Gmsh 2.8

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Gmsh

Christophe Geuzaine and Jean-François Remacle

Gmsh is an automatic 3D finite element mesh generator with build-in pre- and post-processing facilities. This is the Gmsh Reference Manual for Gmsh 2.8 (7 February 2014).

--- The Detailed Node Listing ---

Overview

How to read this reference manual?

Running Gmsh on your system

General tools

Expressions

Geometry module

Geometry commands

Mesh module

Mesh commands

Solver module

Post-processing module

File formats

Legacy formats

Tutorial

Options

Information for developers

Frequently asked questions


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Obtaining Gmsh

The source code and various pre-compiled versions of Gmsh (for Windows, Mac and Unix) can be downloaded from http://geuz.org/gmsh/. Gmsh is also directly available in pre-packaged form in various Linux and BSD distributions (Debian, Ubuntu, FreeBSD, ...).

If you use Gmsh, we would appreciate that you mention it in your work by citing the following paper: “C. Geuzaine and J.-F. Remacle, Gmsh: a three-dimensional finite element mesh generator with built-in pre- and post-processing facilities. International Journal for Numerical Methods in Engineering, Volume 79, Issue 11, pages 1309-1331, 2009”. A preprint of that paper as well as other references and the latest news about Gmsh development are available on http://geuz.org/gmsh/.


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Copying conditions

Gmsh is “free software”; this means that everyone is free to use it and to redistribute it on a free basis. Gmsh is not in the public domain; it is copyrighted and there are restrictions on its distribution, but these restrictions are designed to permit everything that a good cooperating citizen would want to do. What is not allowed is to try to prevent others from further sharing any version of Gmsh that they might get from you.

Specifically, we want to make sure that you have the right to give away copies of Gmsh, that you receive source code or else can get it if you want it, that you can change Gmsh or use pieces of Gmsh in new free programs, and that you know you can do these things.

To make sure that everyone has such rights, we have to forbid you to deprive anyone else of these rights. For example, if you distribute copies of Gmsh, you must give the recipients all the rights that you have. You must make sure that they, too, receive or can get the source code. And you must tell them their rights.

Also, for our own protection, we must make certain that everyone finds out that there is no warranty for Gmsh. If Gmsh is modified by someone else and passed on, we want their recipients to know that what they have is not what we distributed, so that any problems introduced by others will not reflect on our reputation.

The precise conditions of the license for Gmsh are found in the General Public License that accompanies the source code (see License). Further information about this license is available from the GNU Project webpage http://www.gnu.org/copyleft/gpl-faq.html. Detailed copyright information can be found in Copyright and credits.

If you want to integrate parts of Gmsh into a closed-source software, or want to sell a modified closed-source version of Gmsh, you will need to obtain a different license. Please contact us directly for more information.


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1 Overview

Gmsh is a three-dimensional finite element grid generator with a build-in CAD engine and post-processor. Its design goal is to provide a fast, light and user-friendly meshing tool with parametric input and advanced visualization capabilities.

Gmsh is built around four modules: geometry, mesh, solver and post-processing. All geometrical, mesh, solver and post-processing instructions are prescribed either interactively using the graphical user interface (GUI) or in text files using Gmsh's own scripting language. Interactive actions generate language bits in the input files, and vice versa. This makes it possible to automate all treatments, using loops, conditionals and external system calls. A brief description of the four modules is given hereafter.


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1.1 Geometry: geometrical entity definition

Gmsh uses a boundary representation (“BRep”) to describe geometries. Models are created in a bottom-up flow by successively defining points, oriented lines (line segments, circles, ellipses, splines, ...), oriented surfaces (plane surfaces, ruled surfaces, triangulated surfaces, ...) and volumes. Groups of geometrical entities (called “physical groups”) can also be defined, based on these elementary geometric entities. Gmsh's scripting language allows all geometrical entities to be fully parametrized.


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1.2 Mesh: finite element mesh generation

A finite element mesh is a tessellation of a given subset of the three-dimensional space by elementary geometrical elements of various shapes (in Gmsh's case: lines, triangles, quadrangles, tetrahedra, prisms, hexahedra and pyramids), arranged in such a way that if two of them intersect, they do so along a face, an edge or a node, and never otherwise. All the finite element meshes produced by Gmsh are considered as “unstructured”, even if they were generated in a “structured” way (e.g., by extrusion). This implies that the elementary geometrical elements are defined only by an ordered list of their nodes but that no predefined order relation is assumed between any two elements.

The mesh generation is performed in the same bottom-up flow as the geometry creation: lines are discretized first; the mesh of the lines is then used to mesh the surfaces; then the mesh of the surfaces is used to mesh the volumes. In this process, the mesh of an entity is only constrained by the mesh of its boundary. For example, in three dimensions, the triangles discretizing a surface will be forced to be faces of tetrahedra in the final 3D mesh only if the surface is part of the boundary of a volume; the line elements discretizing a curve will be forced to be edges of tetrahedra in the final 3D mesh only if the curve is part of the boundary of a surface, itself part of the boundary of a volume; a single node discretizing a point in the middle of a volume will be forced to be a vertex of one of the tetrahedra in the final 3D mesh only if this point is connected to a curve, itself part of the boundary of a surface, itself part of the boundary of a volume. This automatically assures the conformity of the mesh when, for example, two surfaces share a common line. But this also implies that the discretization of an “isolated” (n-1)-th dimensional entity inside an n-th dimensional entity does not constrain the n-th dimensional mesh—unless it is explicitly told to do so (see Miscellaneous mesh commands). Every meshing step is constrained by a “size field” (sometimes called “characteristic length field”), which prescribes the desired size of the elements in the mesh. This size field can be uniform, specified by values associated with points in the geometry, or defined by general “fields” (for example related to the distance to some boundary, to a arbitrary scalar field defined on another mesh, etc.).

For each meshing step, all structured mesh directives are executed first, and serve as additional constraints for the unstructured parts 1.


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1.3 Solver: external solver interface

External solvers can be interfaced with Gmsh through Unix or TCP/IP sockets, which permits to modify solver parameters, launch external computations and process the results directly from within Gmsh's post-processing module. The default solver interfaced with Gmsh is GetDP (http://geuz.org/getdp/). Examples on how to interface other solvers are available in the source distribution (in the utils/solvers/ directory).


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1.4 Post-processing: scalar, vector and tensor field visualization

Gmsh can load and manipulate multiple post-processing scalar, vector or tensor maps along with the geometry and the mesh. Scalar fields are represented by iso-value lines/surfaces or color maps, while vector fields are represented by three-dimensional arrows or displacement maps. Post-processing functions include section computation, offset, elevation, boundary and component extraction, color map and range modification, animation, vector graphic output, etc. All the post-processing options can be accessed either interactively or through the input script files. Scripting permits to automate all post-processing operations, as for example to create animations. User-defined operations can also be performed on post-processing views through dynamically loadable plugins.


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1.5 What Gmsh is pretty good at ...

Here is a tentative list of what Gmsh does best:


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1.6 ... and what Gmsh is not so good at

As of version 2.8, here are some known weaknesses of Gmsh:

If you have the skills and some free time, feel free to join the project: we gladly accept any code contributions (see Information for developers) to remedy the aforementioned (and all other) shortcomings!


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1.7 Bug reports

If you think you have found a bug in Gmsh, you can report it by email to the public Gmsh mailing list at gmsh@geuz.org, or file it directly into our bug tracking database at https://geuz.org/trac/gmsh/report (login: gmsh, password: gmsh). Please send as precise a description of the problem as you can, including sample input files that produce the bug. Don't forget to mention both the version of Gmsh and the version of your operation system (see Command-line options to see how to get this information).

See Frequently asked questions, and the bug tracking system to see which problems we already know about.


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2 How to read this reference manual?

Gmsh can be used at three levels:

  1. as a stand-alone graphical program, driven by an interactive graphical user interface (GUI);
  2. as a stand-alone script-driven program;
  3. as a library.

You can skip most of this reference manual if you only want to use Gmsh at the first level (i.e., interactively with the GUI). Just read the next chapter (see Running Gmsh on your system) to learn how to launch Gmsh on your system, then go experiment with the GUI and the tutorial files (see Tutorial) provided in the distribution. Screencasts that show how to use the GUI are available here: http://geuz.org/gmsh/screencasts/.

The aim of the reference manual is to explain everything you need to use Gmsh at the second level, i.e., using the built-in scripting language. A Gmsh script file is an ASCII text file that contains instructions in Gmsh's built-in scripting language. Such a file is interpreted by Gmsh's parser, and can be given any extension (or no extension at all). By convention, Gmsh uses the .geo extension for geometry scripts, and the .pos extension for parsed post-processing datasets. Once you master the tutorial (read the source files: they are heavily commented!), start reading chapter General tools, then proceed with the next four chapters, which detail the syntax of the geometry, mesh, solver and post-processing scripting commands. You will see that most of the interactive actions in the GUI have a direct equivalent in the scripting language. If you want to use Gmsh as a pre- or post-processor for your own software, you will also want to learn about the non-scripting input/output files that Gmsh can read/write. In addition to Gmsh's native “MSH” file format (see File formats), Gmsh can read/write many standard mesh files, depending on how it was built: check the `File->Save As' menu for a list of available formats.

Finally, to use Gmsh at the third level (i.e., to link the Gmsh library with your own code), you will need to learn the internal Gmsh Application Programming Interface (API). No complete documentation of this API is available yet; a good starting point is Source code structure, which gives a short introduction to Gmsh's internal source code structure. Then have a look e.g. at the examples in the utils/api_demos/ directory in the source code. To build the library see the instructions in Compiling the source code and in the top-level README.txt file in the source distribution.


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2.1 Syntactic rules used in the manual

Here are the rules we tried to follow when writing this reference manual. Note that metasyntactic variable definitions stay valid throughout the manual (and not only in the sections where the definitions appear).

  1. Keywords and literal symbols are printed like this.
  2. Metasyntactic variables (i.e., text bits that are not part of the syntax, but stand for other text bits) are printed like this.
  3. A colon (:) after a metasyntactic variable separates the variable from its definition.
  4. Optional rules are enclosed in < > pairs.
  5. Multiple choices are separated by |.
  6. Three dots (...) indicate a possible (multiple) repetition of the preceding rule.


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3 Running Gmsh on your system


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3.1 Interactive mode

To launch Gmsh in interactive mode, just double-click on the Gmsh icon, or type

     > gmsh

at your shell prompt in a terminal. This will open the main Gmsh window, with a tree-like menu on the left, a graphic area on the right, and a status bar at the bottom. (You can detach the tree menu using `Window->Attach/Detach Menu'.)

To open the first tutorial file (see Tutorial), select the `File->Open' menu, and choose t1.geo. When using a terminal, you can specify the file name directly on the command line, i.e.:

     > gmsh t1.geo

To perform the mesh generation, go to the mesh module (by selecting `Mesh' in the tree) and choose the dimension (`1D' will mesh all the lines; `2D' will mesh all the surfaces—as well as all the lines if `1D' was not called before; `3D' will mesh all the volumes—and all the surfaces if `2D' was not called before). To save the resulting mesh in the current mesh format click on `Save', or select the appropriate format and file name with the `File->Save As' menu. The default mesh file name is based on the name of the current active model, with an appended extension depending on the mesh format2.

To create a new geometry or to modify an existing geometry, select 'Geometry' in the tree. For example, to create a spline, select `Elementary', `Add', `New' and `Spline'. You will then be asked to select a list of points, and to type e to finish the selection (or q to abort it). Once the interactive command is completed, a text string is automatically added at the end of the current script file. You can edit the script file by hand at any time by pressing the `Edit' button in the `Geometry' menu and then reloading the model by pressing `Reload'. For example, it is often faster to define variables and points directly in the script file, and then use the GUI to define the lines, the surfaces and the volumes interactively.

Several files can be loaded simultaneously in Gmsh. When specified on the command line, the first one defines the active model and the others are `merged' into this model. You can merge such files with the `File->Merge' menu. For example, to merge the post-processing views contained in the files view1.pos and view5.msh together with the geometry of the first tutorial t1.geo, you can type the following command:

     > gmsh t1.geo view1.pos view5.msh

In the Post-Processing module (select `Post-Processing' in the tree), three items will appear, respectively labeled `A scalar map', `Nodal scalar map' and `Element 1 vector'. In this example the views contain several time steps: you can loop through them with the small “remote-control” icons in the status bar. A mouse click on the view name will toggle the visibility of the selected view, while a click on the arrow button on the right will provide access to the view's options.

Note that all the options specified interactively can also be directly specified in the script files. You can save the current options of the current active model with the `File->Save Model Options'. This will create a new option file with the same filename as the active model, but with an extra .opt extension added. The next time you open this model, the associated options will be automatically loaded, too. To save the current options as your default preferences for all future Gmsh sessions, use the `File->Save Options As Default' menu instead. Finally, you can also save the current options in an arbitrary file by choosing the `Gmsh options' format in `File->Save As'.

For more information about available options (and how to reset them to their default values), see Options. A full list of options with their current values is also available in the `Help->Current Options' menu.


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3.2 Non-interactive mode

Gmsh can be run non-interactively in `batch' mode, without GUI3. For example, to mesh the first tutorial in batch mode, just type:

     > gmsh t1.geo -2

To mesh the same example, but with the background mesh available in the file bgmesh.pos, type:

     > gmsh t1.geo -2 -bgm bgmesh.pos

For the list of all command-line options, see Command-line options.


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3.3 Command-line options

Geometry options:
-0
Output model, then exit
-tol float
Set geometrical tolerance
-match
Match geometries and meshes
Mesh options:
-1, -2, -3
Perform 1D, 2D or 3D mesh generation, then exit
-o file
Specify output file name
-format string
Select output mesh format (auto (default), msh, msh1, msh2, unv, vrml, ply2, stl, mesh, bdf, cgns, p3d, diff, med, ...)
-bin
Use binary format when available
-refine
Perform uniform mesh refinement, then exit
-part int
Partition after batch mesh generation
-partWeight tri|quad|tet|prism|hex int
Weight of a triangle/quad/etc. during partitioning
-saveall
Save all elements (discard physical group definitions)
-parametric
Save vertices with their parametric coordinates
-algo string
Select mesh algorithm (meshadapt, del2d, front2d, delquad, del3d, front3d, mmg3d)
-smooth int
Set number of mesh smoothing steps
-order int
Set mesh order (1, ..., 5)
-optimize[_netgen]
Optimize quality of tetrahedral elements
-optimize_ho
Optimize high order meshes
-ho_[min,max,nlayers]
High-order optimization parameters
-optimize_lloyd
Optimize 2D meshes using Lloyd algorithm
-clscale float
Set global mesh element size scaling factor
-clmin float
Set minimum mesh element size
-clmax float
Set maximum mesh element size
-anisoMax float
Set maximum anisotropy (only used in bamg for now)
-smoothRatio float
Set smoothing ration between mesh sizes at nodes of a same edge (only used in bamg)
-clcurv
Automatically compute element sizes from curvatures
-epslc1d
Set accuracy of evaluation of LCFIELD for 1D mesh
-swapangle
Set the threshold angle (in degree) between two adjacent faces below which a swap is allowed
-rand float
Set random perturbation factor
-bgm file
Load background mesh from file
-check
Perform various consistency checks on mesh
-mpass int
Do several passes on the mesh for complex backround fields
-ignorePartBound
Ignore partitions boundaries
Post-processing options:
-link int
Select link mode between views (0, 1, 2, 3, 4)
-combine
Combine views having identical names into multi-time-step views
Display options:
-n
Hide all meshes and post-processing views on startup
-nodb
Disable double buffering
-numsubedges
Set num of subdivisions for high order element display
-fontsize int
Specify the font size for the GUI
-theme string
Specify FLTK GUI theme
-display string
Specify display
-camera
Use camera mode view;
-stereo
OpenGL quad-buffered stereo rendering (requires special graphic card)
-gamepad
Use gamepad controller if available
Other options:
-, -parse_and_exit
Parse input files, then exit
-new
Create new model before merge next file
-merge
Merge next files
-open
Open next files
-a, -g, -m, -s, -p
Start in automatic, geometry, mesh, solver or post-processing mode
-pid
Print process id on stdout
-listen
Always listen to incoming connection requests
-watch pattern
Pattern of files to merge as they become available
-v int
Set verbosity level
-nopopup
Don't popup dialog windows in scripts
-string "string"
Parse command string at startup
-setnumber name value
Set constant number name=value
-setstring name value
Set constant string name=value
-option file
Parse option file at startup
-convert files
Convert files into latest binary formats, then exit
-version
Show version number
-info
Show detailed version information
-help
Show command line usage


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3.4 Mouse actions

Move
- Highlight the entity under the mouse pointer and display its properties
- Resize a lasso zoom or a lasso (un)selection
Left button
- Rotate
- Select an entity
- Accept a lasso zoom or a lasso selection
Ctrl+Left button
Start a lasso zoom or a lasso (un)selection
Middle button
- Zoom
- Unselect an entity
- Accept a lasso zoom or a lasso unselection
Ctrl+Middle button
Orthogonalize display
Right button
- Pan
- Cancel a lasso zoom or a lasso (un)selection
- Pop-up menu on post-processing view button
Ctrl+Right button
Reset to default viewpoint

For a 2 button mouse, Middle button = Shift+Left button.

For a 1 button mouse, Middle button = Shift+Left button, Right button = Alt+Left button.


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3.5 Keyboard shortcuts

(On Mac Ctrl is replaced by Cmd (the `Apple key') in the shortcuts below.)

Left arrow
Go to previous time step
Right arrow
Go to next time step
Up arrow
Make previous view visible
Down arrow
Make next view visible
0
Reload project file
1 or F1
Mesh lines
2 or F2
Mesh surfaces
3 or F3
Mesh volumes
Escape
Cancel lasso zoom/selection, toggle mouse selection ON/OFF
g
Go to geometry module
m
Go to mesh module
p
Go to post-processing module
s
Go to solver module
Shift+a
Bring all windows to front
Shift+g
Show geometry options
Shift+m
Show mesh options
Shift+o
Show general options
Shift+p
Show post-processing options
Shift+s
Show solver options
Shift+u
Show post-processing view plugins
Shift+w
Show post-processing view options
Shift+Escape
Enable full mouse selection
Ctrl+d
Attach/detach menu
Ctrl+f
Enter full screen
Ctrl+i
Show statistics window
Ctrl+j
Save model options
Ctrl+l
Show message console
Ctrl+m
Minimize window
Ctrl+n
Create new project file
Ctrl+o
Open project file
Ctrl+q
Quit
Ctrl+r
Rename project file
Ctrl+s
Save file as
Shift+Ctrl+c
Show clipping plane window
Shift+Ctrl+j
Save options as default
Shift+Ctrl+m
Show manipulator window
Shift+Ctrl+n
Show option window
Shift+Ctrl+o
Merge file(s)
Shift+Ctrl+s
Save mesh in default format
Shift+Ctrl+u
Show plugin window
Shift+Ctrl+v
Show visibility window
Alt+a
Loop through axes modes
Alt+b
Hide/show bounding boxes
Alt+c
Loop through predefined color schemes
Alt+e
Hide/Show element outlines for visible post-pro views
Alt+f
Change redraw mode (fast/full)
Alt+h
Hide/show all post-processing views
Alt+i
Hide/show all post-processing view scales
Alt+l
Hide/show geometry lines
Alt+m
Toggle visibility of all mesh entities
Alt+n
Hide/show all post-processing view annotations
Alt+o
Change projection mode (orthographic/perspective)
Alt+p
Hide/show geometry points
Alt+r
Loop through range modes for visible post-pro views
Alt+s
Hide/show geometry surfaces
Alt+t
Loop through interval modes for visible post-pro views
Alt+v
Hide/show geometry volumes
Alt+w
Enable/disable all lighting
Alt+x
Set X view
Alt+y
Set Y view
Alt+z
Set Z view
Alt+Shift+a
Hide/show small axes
Alt+Shift+b
Hide/show mesh volume faces
Alt+Shift+d
Hide/show mesh surface faces
Alt+Shift+l
Hide/show mesh lines
Alt+Shift+p
Hide/show mesh points
Alt+Shift+s
Hide/show mesh surface edges
Alt+Shift+v
Hide/show mesh volume edges
Alt+Shift+w
Reverse all mesh normals
Alt+Shift+x
Set -X view
Alt+Shift+y
Set -Y view
Alt+Shift+z
Set -Z view


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4 General tools

This chapter describes the general commands and options that can be used in Gmsh's script files. By “general”, we mean “not specifically related to one of the geometry, mesh, solver or post-processing modules”. Commands peculiar to these modules will be introduced in Geometry module, Mesh module, Solver module, and Post-processing module, respectively.


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4.1 Comments

Gmsh script files support both C and C++ style comments:

  1. any text comprised between /* and */ pairs is ignored;
  2. the rest of a line after a double slash // is ignored.

These commands won't have the described effects inside double quotes or inside keywords. Also note that `white space' (spaces, tabs, new line characters) is ignored inside all expressions.


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4.2 Expressions

The two constant types used in Gmsh scripts are real and string (there is no integer type). These types have the same meaning and syntax as in the C or C++ programming languages.


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4.2.1 Floating point expressions

Floating point expressions (or, more simply, “expressions”) are denoted by the metasyntactic variable expression (remember the definition of the syntactic rules in Syntactic rules), and are evaluated during the parsing of the script file:

     expression:
       real |
       string |
       string ~ { expression }
       string [ expression ] |
       # string [ ] |
       ( expression ) |
       operator-unary-left expression |
       expression operator-unary-right |
       expression operator-binary expression |
       expression operator-ternary-left expression operator-ternary-right expression |
       built-in-function |
       real-option |
       StrFind(char-expression, char-expression) |
       StrCmp(char-expression, char-expression) |
       TextAttributes(char-expression<,char-expression...>) |
       GetValue("string", expression)

Such expressions are used in most of Gmsh's scripting commands. When ~{expression} is appended to a string string, the result is a new string formed by the concatenation of string, _ (an underscore) and the value of the expression. This is most useful in loops (see Loops and conditionals), where it permits to define unique strings automatically. For example,

     For i In {1:3}
       x~{i} = i;
     EndFor

is the same as

     x_1 = 1;
     x_2 = 2;
     x_3 = 3;

The brackets [] permit to extract one item from a list and to get the size of a list, respectively. The operators operator-unary-left, operator-unary-right, operator-binary, operator-ternary-left and operator-ternary-right are defined in Operators. For the definition of built-in-functions, see Built-in functions. The various real-options are listed in Options. StrFind searches the first char-expression for any occurrence of the second char-expression. StrCmp compares the two strings (returns an integer greater than, equal to, or less than 0, according as the first string is greater than, equal to, or less than the second string). TextAttributes creates attributes for text strings.

The last case in the definition allows to ask the user for a value interactively. For example, inserting GetValue("Value of parameter alpha?", 5.76) in an input file will query the user for the value of a certain parameter alpha, assuming the default value is 5.76. If the option General.NoPopup is set (see General options list), no question is asked and the default value is automatically used.

List of expressions are also widely used, and are defined as:

     expression-list:
       expression-list-item <, expression-list-item> ...

with

     expression-list-item:
       expression |
       expression : expression |
       expression : expression : expression |
       string [ ] |
       string ( ) |
       List [ string ] |
       string [ { expression-list } ] |
       string ( { expression-list } ) |
       Point { expression } |
       transform |
       extrude
       Point { expression } |
       Point|Line|Surface|Volume "*" |
       Physical Point|Line|Surface|Volume { expression-list }
     

The second case in this last definition permits to create a list containing the range of numbers comprised between two expressions, with a unit incrementation step. The third case also permits to create a list containing the range of numbers comprised between two expressions, but with a positive or negative incrementation step equal to the third expression. The fourth, fifth and sixth cases permit to reference an expression list. The seventh and eight cases permit to reference an expression sublist (whose elements are those corresponding to the indices provided by the expression-list). The next two cases permit to retrieve the indices of entities created through geometrical transformations and extrusions (see Transformations, and Extrusions). The last three cases permit to retrieve the coordinates of a given geometry point (see Points), to retrieve the id numbers of all points, lines, surfaces or volumes in the model, or to retrieve the elementary entities making up physical groups.

To see the practical use of such expressions, have a look at the first couple of examples in Tutorial. Note that, in order to lighten the syntax, you can omit the braces {} enclosing an expression-list if this expression-list only contains a single item. Also note that a braced expression-list can be preceded by a minus sign in order to change the sign of all the expression-list-items.


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4.2.2 Character expressions

Character expressions are defined as:

     char-expression:
       "string" |
       Today |
       StrPrefix ( char-expression ) |
       StrRelative ( char-expression ) |
       StrCat ( char-expression , char-expression ) |
       Str ( char-expression , ... ) |
       Sprintf ( char-expression , expression-list ) |
       Sprintf ( char-expression ) |
       Sprintf ( char-option ) |
       GetEnv ( char-expression ) |
       GetString ( char-expression , char-expression ) |
       StrReplace ( char-expression , char-expression , char-expression )

StrPrefix and StrRelative permit to take the prefix (e.g. to remove the extension) or the relative path of a file name. StrCat and Str permit to concatenate character expressions (Str adds a newline character after each string except the last). Sprintf is equivalent to the sprintf C function (where char-expression is a format string that can contain floating point formatting characters: %e, %g, etc.) The various char-options are listed in Options. GetEnvThe gets the value of an environment variable from the operating system. GetString allows to ask the user for a value interactively. StrReplace's arguments are: input string, old substring, new substring.4

Character expressions are mostly used to specify non-numeric options and input/output file names. See t8.geo, for an interesting usage of char-expressions in an animation script.


Previous: Character expressions, Up: Expressions

4.2.3 Color expressions

Colors expressions are hybrids between fixed-length braced expression-lists and strings:

     color-expression:
       string |
       { expression, expression, expression } |
       { expression, expression, expression, expression } |
       color-option

The first case permits to use the X Windows names to refer to colors, e.g., Red, SpringGreen, LavenderBlush3, ... (see Common/Colors.h in the source code for a complete list). The second case permits to define colors by using three expressions to specify their red, green and blue components (with values comprised between 0 and 255). The third case permits to define colors by using their red, green and blue color components as well as their alpha channel. The last case permits to use the value of a color-option as a color-expression. The various color-options are listed in Options.

See t3.geo, for an example of the use of color expressions.


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4.3 Operators

Gmsh's operators are similar to the corresponding operators in C and C++. Here is the list of the unary, binary and ternary operators currently implemented.

operator-unary-left:

-
Unary minus.
!
Logical not.

operator-unary-right:

++
Post-incrementation.
--
Post-decrementation.

operator-binary:

^
Exponentiation.
*
Multiplication.
/
Division.
%
Modulo.
+
Addition.
-
Subtraction.
==
Equality.
!=
Inequality.
>
Greater.
>=
Greater or equality.
<
Less.
<=
Less or equality.
&&
Logical `and'.
||
Logical `or'. (Warning: the logical `or' always implies the evaluation of both arguments. That is, unlike in C or C++, the second operand of || is evaluated even if the first one is true).

operator-ternary-left:

?
operator-ternary-right:
:
The only ternary operator, formed by operator-ternary-left and operator-ternary-right, returns the value of its second argument if the first argument is non-zero; otherwise it returns the value of its third argument.

The evaluation priorities are summarized below5 (from stronger to weaker, i.e., * has a highest evaluation priority than +). Parentheses () may be used anywhere to change the order of evaluation:

  1. (), [], ., #
  2. ^
  3. !, ++, --, - (unary)
  4. *, /, %
  5. +, -
  6. <, >, <=, >=
  7. ==, !=
  8. &&
  9. ||
  10. ?:
  11. =, +=, -=, *=, /=


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4.4 Built-in functions

A built-in function is composed of an identifier followed by a pair of parentheses containing an expression-list (the list of its arguments)6. Here is the list of the built-in functions currently implemented:

build-in-function:

Acos ( expression )
Arc cosine (inverse cosine) of an expression in [-1,1]. Returns a value in [0,Pi].
Asin ( expression )
Arc sine (inverse sine) of an expression in [-1,1]. Returns a value in [-Pi/2,Pi/2].
Atan ( expression )
Arc tangent (inverse tangent) of expression. Returns a value in [-Pi/2,Pi/2].
Atan2 ( expression, expression )
Arc tangent (inverse tangent) of the first expression divided by the second. Returns a value in [-Pi,Pi].
Ceil ( expression )
Rounds expression up to the nearest integer.
Cos ( expression )
Cosine of expression.
Cosh ( expression )
Hyperbolic cosine of expression.
Exp ( expression )
Returns the value of e (the base of natural logarithms) raised to the power of expression.
Fabs ( expression )
Absolute value of expression.
Fmod ( expression, expression )
Remainder of the division of the first expression by the second, with the sign of the first.
Floor ( expression )
Rounds expression down to the nearest integer.
Hypot ( expression, expression )
Returns the square root of the sum of the square of its two arguments.
Log ( expression )
Natural logarithm of expression (expression > 0).
Log10 ( expression )
Base 10 logarithm of expression (expression > 0).
Modulo ( expression, expression )
see Fmod( expression, expression ).
Rand ( expression )
Random number between zero and expression.
Round ( expression )
Rounds expression to the nearest integer.
Sqrt ( expression )
Square root of expression (expression >= 0).
Sin ( expression )
Sine of expression.
Sinh ( expression )
Hyperbolic sine of expression.
Tan ( expression )
Tangent of expression.
Tanh ( expression )
Hyperbolic tangent of expression.


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4.5 User-defined functions

User-defined functions take no arguments, and are evaluated as if a file containing the function body was included at the location of the Call statement.

Function string
Begins the declaration of a user-defined function named string. The body of the function starts on the line after `Function string', and can contain any Gmsh command.
Return
Ends the body of the current user-defined function. Function declarations cannot be imbricated.
Call string;
Executes the body of a (previously defined) function named string.

See t5.geo, for an example of a user-defined function. A shortcoming of Gmsh's scripting language is that all variables are “public”. Variables defined inside the body of a function will thus be available outside, too!


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4.6 Loops and conditionals

Loops and conditionals are defined as follows, and can be imbricated:

For ( expression : expression )
Iterates from the value of the first expression to the value of the second expression, with a unit incrementation step. At each iteration, the commands comprised between `For ( expression : expression )' and the matching EndFor are executed.
For ( expression : expression : expression )
Iterates from the value of the first expression to the value of the second expression, with a positive or negative incrementation step equal to the third expression. At each iteration, the commands comprised between `For ( expression : expression : expression )' and the matching EndFor are executed.
For string In { expression : expression }
Iterates from the value of the first expression to the value of the second expression, with a unit incrementation step. At each iteration, the value of the iterate is affected to an expression named string, and the commands comprised between `For string In { expression : expression }' and the matching EndFor are executed.
For string In { expression : expression : expression }
Iterates from the value of the first expression to the value of the second expression, with a positive or negative incrementation step equal to the third expression. At each iteration, the value of the iterate is affected to an expression named string, and the commands comprised between `For string In { expression : expression : expression }' and the matching EndFor are executed.
EndFor
Ends a matching For command.
If ( expression )
The body enclosed between `If ( expression )' and the matching Endif is evaluated if expression is non-zero.
EndIf
Ends a matching If command.

See t5.geo, for an example of For and If commands. Gmsh does not provide any Else (or similar) command at the time of this writing.


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4.7 General commands

The following commands can be used anywhere in a Gmsh script:

string = expression;
Creates a new expression identifier string, or affects expression to an existing expression identifier. Thirteen expression identifiers are predefined (hardcoded in Gmsh's parser):
Pi
Returns 3.1415926535897932.
GMSH_MAJOR_VERSION
Returns Gmsh's major version number.
GMSH_MINOR_VERSION
Returns Gmsh's minor version number.
GMSH_PATCH_VERSION
Returns Gmsh's patch version number.
MPI_Size
Returns the number of processors on which Gmsh is running. It is always 1, except if you compiled Gmsh with ENABLE_MPI (see Compiling the source code).
MPI_Rank
Returns the rank of the current processor.
Cpu
Returns the current CPU time (in seconds).
Memory
Returns the current memory usage (in Mb).
newp
Returns the next available point number. As explained in Geometry module, a unique number must be associated with every geometrical point: newp permits to know the highest number already attributed (plus one). This is mostly useful when writing user-defined functions (see User-defined functions) or general geometric primitives, when one does not know a priori which numbers are already attributed, and which ones are still available.
newl
Returns the next available line number.
news
Returns the next available surface number.
newv
Returns the next available volume number.
newll
Returns the next available line loop number.
newsl
Returns the next available surface loop number.
newreg
Returns the next available region number. That is, newreg returns the maximum of newp, newl, news, newv, newll, newsl and all physical entity numbers7.

string = { };
Creates a new expression list identifier string with an empty list.
string = { expression-list };
Creates a new expression list identifier string with the list expression-list, or affects expression-list to an existing expression list identifier. The following syntax is also allowed: string[] = { expression-list };
string [ { expression-list } ] = { expression-list };
Affects each item in the right hand side expression-list to the elements (indexed by the left hand side expression-list) of an existing expression list identifier. The two expression-lists must contain the same number of items.
string ( { expression-list } ) = { expression-list };
Same as above.
string += expression;
Adds and affects expression to an existing expression identifier.
string -= expression;
Subtracts and affects expression to an existing expression identifier.
string *= expression;
Multiplies and affects expression to an existing expression identifier.
string /= expression;
Divides and affects expression to an existing expression identifier.
string += { expression-list };
Appends expression-list to an existing expression list or creates a new expression list with expression-list.
string -= { expression-list };
Removes the items in expression-list from the existing expression list.
string [ { expression-list } ] += { expression-list };
Adds and affects, item per item, the right hand side expression-list to an existing expression list identifier.
string [ { expression-list } ] -= { expression-list };
Subtracts and affects, item per item, the right hand side expression-list to an existing expression list identifier.
string [ { expression-list } ] *= { expression-list };
Multiplies and affects, item per item, the right hand side expression-list to an existing expression list identifier.
string [ { expression-list } ] /= { expression-list };
Divides and affects, item per item, the right hand side expression-list to an existing expression list identifier.
string = char-expression;
Creates a new character expression identifier string with a given char-expression.
real-option = expression;
Affects expression to a real option.
char-option = char-expression;
Affects char-expression to a character option.
color-option = color-expression;
Affects color-expression to a color option.
real-option += expression;
Adds and affects expression to a real option.
real-option -= expression;
Subtracts and affects expression to a real option.
real-option *= expression;
Multiplies and affects expression to a real option.
real-option /= expression;
Divides and affects expression to a real option.
Abort;
Aborts the current script.
Exit;
Exits Gmsh.
Printf ( char-expression <, expression-list> );
Prints a character expression in the information window and/or on the terminal. Printf is equivalent to the printf C function: char-expression is a format string that can contain formatting characters (%f, %e, etc.). Note that all expressions are evaluated as floating point values in Gmsh (see Expressions), so that only valid floating point formatting characters make sense in char-expression. See t5.geo, for an example of the use of Printf.
Printf ( char-expression , expression-list ) > char-expression;
Same as Printf above, but output the expression in a file.
Printf ( char-expression , expression-list ) >> char-expression;
Same as Printf above, but appends the expression at the end of the file.
Error ( char-expression <, expression-list> );
Same as Printf, but raises an error.
Merge char-expression;
Merges a file named char-expression. This command is equivalent to the `File->Merge' menu in the GUI. If the path in char-expression is not absolute, char-expression is appended to the path of the current file.
Draw;
Redraws the scene.
SetChanged;
Force the mesh and post-processing vertex arrays to be regenerated. Useful e.g. for creating animations with changing clipping planes, etc.
BoundingBox;
Recomputes the bounding box of the scene (which is normally computed only after new geometrical entities are added or after files are included or merged). The bounding box is computed as follows:
  1. If there is a mesh (i.e., at least one mesh vertex), the bounding box is taken as the box enclosing all the mesh vertices;
  2. If there is no mesh but there is a geometry (i.e., at least one geometrical point), the bounding box is taken as the box enclosing all the geometrical points;
  3. If there is no mesh and no geometry, but there are some post-processing views, the bounding box is taken as the box enclosing all the primitives in the views.

BoundingBox { expression, expression, expression, expression, expression, expression };
Forces the bounding box of the scene to the given expressions (X min, X max, Y min, Y max, Z min, Z max).
Delete Model;
Deletes the current model (all geometrical entities and their associated meshes).
Delete Physicals;
Deletes all physical groups.
Delete Variables;
Deletes all the expressions.
Delete Options;
Deletes the current options and revert to the default values.
Delete string;
Deletes the expression string.
Mesh expression;
Generates expression-D mesh.
RefineMesh;
Refines the current mesh by splitting all elements. If Mesh.SecondOrderLinear is set, the new vertices are inserted by linear interpolatinon. Otherwise they are snapped on the actual geometry.
AdaptMesh { expression-list } { expression-list } { { expression-list < , ... > } };
Performs adaptive mesh generation. Documentation not yet available.
RelocateMesh Point | Line | Surface { expression-list } | "*";
Relocates the mesh vertices on the given entities using the parametric coordinates stored in the vertices. Useful for creating perturbation of meshes e.g. for sensitivity analyzes.
SetOrder expression;
Changes the order of the elements in the current mesh.
Print char-expression;
Prints the graphic window in a file named char-expression, using the current Print.Format (see General options list). If the path in char-expression is not absolute, char-expression is appended to the path of the current file.
Sleep expression;
Suspends the execution of Gmsh during expression seconds.
SystemCall char-expression;
Executes a (blocking) system call.
NonBlockingSystemCall char-expression;
Executes a (non-blocking) system call.
SetName char-expression;
Changes the name of the current model.
SyncModel;
Forces an immediate transfer from the old geometrical database into the new one (this transfer normally occurs right after a file is read).
Include char-expression;
Includes the file named char-expression at the current position in the input file. The include command should be given on a line of its own. If the path in char-expression is not absolute, char-expression is appended to the path of the current file.


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4.8 General options

The list of all the general char-options, real-options and color-options (in that order—check the default values to see the actual types) is given in General options list. Most of these options are accessible in the GUI, but not all of them. When running Gmsh interactively, changing an option in the script file will modify the option in the GUI in real time. This permits for example to resize the graphical window in a script, or to interact with animations in the script and in the GUI at the same time.


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5 Geometry module

Gmsh's geometry module provides a simple CAD engine, using a boundary representation (“BRep”) approach: you need to first define points (using the Point command: see below), then lines (using Line, Circle, Spline, ..., commands or by extruding points), then surfaces (using for example the Plane Surface or Ruled Surface commands, or by extruding lines), and finally volumes (using the Volume command or by extruding surfaces).

These geometrical entities are called “elementary” in Gmsh's jargon, and are assigned identification numbers (stricly positive) when they are created:

  1. each elementary point must possess a unique identification number;
  2. each elementary line must possess a unique identification number;
  3. each elementary surface must possess a unique identification number;
  4. each elementary volume must possess a unique identification number.

Elementary geometrical entities can then be manipulated in various ways, for example using the Translate, Rotate, Scale or Symmetry commands. They can be deleted with the Delete command, provided that no higher-dimension entity references them. Zero or negative identification numbers are reserved by the system for special uses: do not use them in your scripts.

Groups of elementary geometrical entities can also be defined and are called “physical” entities. These physical entities cannot be modified by geometry commands: their only purpose is to assemble elementary entities into larger groups, possibly modifying their orientation, so that they can be referred to by the mesh module as single entities. As is the case with elementary entities, each physical point, physical line, physical surface or physical volume must be assigned a unique identification number. See Mesh module, for more information about how physical entities affect the way meshes are saved.


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5.1 Geometry commands

The next subsections describe all the available geometry commands. These commands can be used anywhere in a Gmsh script file. Note that the following general syntax rule is followed for the definition of geometrical entities: “If an expression defines a new entity, it is enclosed between parentheses. If an expression refers to a previously defined entity, it is enclosed between braces.”


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5.1.1 Points

Point ( expression ) = { expression, expression, expression <, expression > };
Creates an elementary point. The expression inside the parentheses is the point's identification number; the three first expressions inside the braces on the right hand side give the three X, Y and Z coordinates of the point in the three-dimensional Euclidean space; the optional last expression sets the prescribed mesh element size at that point. See Specifying mesh element sizes, for more information about how this value is used in the meshing process.
Physical Point ( expression | char-expression ) = { expression-list };
Creates a physical point. The expression inside the parentheses is the physical point's identification number (if a char-expression is given instead, a unique identification number is automatically created); the expression-list on the right hand side should contain the identification numbers of all the elementary points that need to be grouped inside the physical point.


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5.1.2 Lines

BSpline ( expression ) = { expression-list };
Creates a B-spline curve. The expression inside the parentheses is the B-spline curve's identification number; the expression-list on the right hand side should contain the identification numbers of all the B-spline's control points. Repeating control points has the expected effect.
Circle ( expression ) = { expression, expression, expression };
Creates a circle arc (strictly) smaller than Pi. The expression inside the parentheses is the circle arc's identification number; the first expression inside the braces on the right hand side gives the identification number of the start point of the arc; the second expression gives the identification number of the center of the circle; the last expression gives the identification number of the end point of the arc.
CatmullRom ( expression ) = { expression-list };
CatmullRom is a synonym for Spline.
Ellipse ( expression ) = { expression, expression, expression, expression };
Creates an ellipse arc. The expression inside the parentheses is the ellipse arc's identification number; the first expression inside the braces on the right hand side gives the identification number of the start point of the arc; the second expression gives the identification number of the center of the ellipse; the third expression gives the identification number of any point located on the major axis of the ellipse; the last expression gives the identification number of the end point of the arc.
Line ( expression ) = { expression, expression };
Creates a straight line segment. The expression inside the parentheses is the line segment's identification number; the two expressions inside the braces on the right hand side give identification numbers of the start and end points of the segment.
Spline ( expression ) = { expression-list };
Creates a spline curve. The expression inside the parentheses is the spline's identification number; the expression-list on the right hand side should contain the identification numbers of all the spline's control points.
Line Loop ( expression ) = { expression-list };
Creates an oriented line loop. The expression inside the parentheses is the line loop's identification number; the expression-list on the right hand side should contain the identification numbers of all the elementary lines that constitute the line loop. A line loop must be a closed loop, and the elementary lines should be ordered and oriented (using negative identification numbers to specify reverse orientation). If the orientation is correct, but the ordering is wrong, Gmsh will actually reorder the list internally to create a consistent loop. Although Gmsh supports it, it is not recommended to specify multiple line loops (or subloops) in a single Line Loop command. (Line loops are used to create surfaces: see Surfaces.)
Compound Line ( expression ) = { expression-list };
Creates a compound line from several elementary lines. When meshed, a compound line will be reparametrized as a single line, whose mesh can thus cross internal boundaries. The expression inside the parentheses is the compound line's identification number; the expression-list on the right hand side contains the identification number of the elementary lines that should be reparametrized as a single line. See Compound Surface for additional information on compound entities.
Physical Line ( expression | char-expression ) = { expression-list };
Creates a physical line. The expression inside the parentheses is the physical line's identification number (if a char-expression is given instead, a unique identification number is automatically created); the expression-list on the right hand side should contain the identification numbers of all the elementary lines that need to be grouped inside the physical line. Specifying negative identification numbers in the expression-list will reverse the orientation of the mesh elements belonging to the corresponding elementary lines in the saved mesh.


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5.1.3 Surfaces

Plane Surface ( expression ) = { expression-list };
Creates a plane surface. The expression inside the parentheses is the plane surface's identification number; the expression-list on the right hand side should contain the identification numbers of all the line loops defining the surface. The first line loop defines the exterior boundary of the surface; all other line loops define holes in the surface. A line loop defining a hole should not have any lines in common with the exterior line loop (in which case it is not a hole, and the two surfaces should be defined separately). Likewise, a line loop defining a hole should not have any lines in common with another line loop defining a hole in the same surface (in which case the two line loops should be combined).
Ruled Surface ( expression ) = { expression-list } < In Sphere { expression } >;
Creates a ruled surface, i.e., a surface that can be interpolated using transfinite interpolation. The expression inside the parentheses is the ruled surface's identification number; the first expression-list on the right hand side should contain the identification number of a line loop composed of either three or four elementary lines. The optional In Sphere argument forces the surface to be a spherical patch (the extra parameter gives the identification number of the center of the sphere).
Surface Loop ( expression ) = { expression-list };
Creates a surface loop (a shell). The expression inside the parentheses is the surface loop's identification number; the expression-list on the right hand side should contain the identification numbers of all the elementary surfaces that constitute the surface loop. A surface loop must always represent a closed shell, and the elementary surfaces should be oriented consistently (using negative identification numbers to specify reverse orientation). (Surface loops are used to create volumes: see Volumes.)
Compound Surface ( expression ) = { expression-list } < Boundary { { expression-list }, { expression-list }, { expression-list }, { expression-list } } > ;
Creates a compound surface from several elementary surfaces. When meshed, a compound surface will be reparametrized as a single surface, whose mesh can thus cross internal boundaries. Compound surfaces are mostly useful for remeshing discrete models; see “J.-F. Remacle, C. Geuzaine, G. Compere and E. Marchandise, High Quality Surface Remeshing Using Harmonic Maps, International Journal for Numerical Methods in Engineering, 2009” for details as well as the wiki for more examples. The expression inside the parentheses is the compound surface's identification number; the mandatory expression-list on the right hand side contains the identification number of the elementary surfaces that should be reparametrized as a single surface.
Physical Surface ( expression | char-expression ) = { expression-list };
Creates a physical surface. The expression inside the parentheses is the physical surface's identification number (if a char-expression is given instead, a unique identification number is automatically created); the expression-list on the right hand side should contain the identification numbers of all the elementary surfaces that need to be grouped inside the physical surface. Specifying negative identification numbers in the expression-list will reverse the orientation of the mesh elements belonging to the corresponding elementary surfaces in the saved mesh.


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5.1.4 Volumes

Volume ( expression ) = { expression-list };
Creates a volume. The expression inside the parentheses is the volume's identification number; the expression-list on the right hand side should contain the identification numbers of all the surface loops defining the volume. The first surface loop defines the exterior boundary of the volume; all other surface loops define holes in the volume. A surface loop defining a hole should not have any surfaces in common with the exterior surface loop (in which case it is not a hole, and the two volumes should be defined separately). Likewise, a surface loop defining a hole should not have any surfaces in common with another surface loop defining a hole in the same volume (in which case the two surface loops should be combined).
Compound Volume ( expression ) = { expression-list };
Creates a compound volume from several elementary volumes. When meshed, a compound volume will be reparametrized as a single volume, whose mesh can thus cross internal boundaries. The expression inside the parentheses is the compound volume's identification number; the expression-list on the right hand side contains the identification number of the elementary volumes that should be reparametrized as a single volume. See Compound Surface for additional information on compound entities.
Physical Volume ( expression | char-expression ) = { expression-list };
Creates a physical volume. The expression inside the parentheses is the physical volume's identification number (if a char-expression is given instead, a unique identification number is automatically created); the expression-list on the right hand side should contain the identification numbers of all the elementary volumes that need to be grouped inside the physical volume.


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5.1.5 Extrusions

Lines, surfaces and volumes can also be created through extrusion of points, lines and surfaces, respectively. Here is the syntax of the geometrical extrusion commands (go to Structured grids, to see how these commands can be extended in order to also extrude the mesh):

extrude:

Extrude { expression-list } { extrude-list }
Extrudes all elementary entities (points, lines or surfaces) in extrude-list using a translation. The expression-list should contain three expressions giving the X, Y and Z components of the translation vector.
Extrude { { expression-list }, { expression-list }, expression } { extrude-list }
Extrudes all elementary entities (points, lines or surfaces) in extrude-list using a rotation. The first expression-list should contain three expressions giving the X, Y and Z direction of the rotation axis; the second expression-list should contain three expressions giving the X, Y and Z components of any point on this axis; the last expression should contain the rotation angle (in radians).
Extrude { { expression-list }, { expression-list }, { expression-list }, expression } { extrude-list }
Extrudes all elementary entities (points, lines or surfaces) in extrude-list using a translation combined with a rotation. The first expression-list should contain three expressions giving the X, Y and Z components of the translation vector; the second expression-list should contain three expressions giving the X, Y and Z direction of the rotation axis; the third expression-list should contain three expressions giving the X, Y and Z components of any point on this axis; the last expression should contain the rotation angle (in radians).

with

     extrude-list:
       Point | Line | Surface { expression-list }; ...

As explained in Floating point expressions, extrude can be used in an expression, in which case it returns a list of identification numbers. By default, the list contains the “top” of the extruded entity at index 0 and the extruded entity at index 1, followed by the “sides” of the extruded entity at indices 2, 3, etc. For example:

       Point(1) = {0,0,0};
       Point(2) = {1,0,0};
       Line(1) = {1, 2};
       out[] = Extrude{0,1,0}{ Line{1}; };
       Printf("top line = %g", out[0]);
       Printf("surface = %g", out[1]);
       Printf("side lines = %g and %g", out[2], out[3]);

This behaviour can be changed with the Geometry.ExtrudeReturnLateralEntities option (see Geometry options list).


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5.1.6 Transformations

Geometrical transformations can be applied to elementary entities, or to copies of elementary entities (using the Duplicata command: see below). The syntax of the transformation commands is:

transform:

Dilate { { expression-list }, expression } { transform-list }
Scales all elementary entities in transform-list by a factor expression. The expression-list should contain three expressions giving the X, Y and Z direction of the homothetic transformation.
Rotate { { expression-list }, { expression-list }, expression } { transform-list }
Rotates all elementary entities in transform-list by an angle of expression radians. The first expression-list should contain three expressions giving the X, Y and Z direction of the rotation axis; the second expression-list should contain three expressions giving the X, Y and Z components of any point on this axis.
Symmetry { expression-list } { transform-list }
Transforms all elementary entities symmetrically to a plane. The expression-list should contain four expressions giving the coefficients of the plane's equation.
Translate { expression-list } { transform-list }
Translates all elementary entities in transform-list. The expression-list should contain three expressions giving the X, Y and Z components of the translation vector.
Boundary { transform-list }
(Not a transformation per-se.) Returns the boundary of the elementary entities in transform-list.
CombinedBoundary { transform-list }
(Not a transformation per-se.) Returns the boundary of the elementary entities, combined as if a single entity, in transform-list. Useful to compute the boundary of a complex part.

with

     transform-list:
       Point | Line | Surface | Volume { expression-list }; ... |
       Duplicata { Point | Line | Surface | Volume { expression-list }; ... } |
       transform


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5.1.7 Miscellaneous

Here is a list of all other geometry commands currently available:

Coherence;
Removes all duplicate elementary geometrical entities (e.g., points having identical coordinates). Note that Gmsh executes the Coherence command automatically after each geometrical transformation, unless Geometry.AutoCoherence is set to zero (see Geometry options list).
Delete { Point | Line | Surface | Volume { expression-list }; ... }
Deletes all elementary entities whose identification numbers are given in expression-list. If an entity is linked to another entity (for example, if a point is used as a control point of a curve), Delete has no effect (the line will have to be deleted before the point can).
< Recursive > Hide { Point | Line | Surface | Volume { expression-list }; ... }
Hide the entities listed in expression-list, if General.VisibilityMode is set to 0 or 1.
Hide char-expression;
Hide the entity char-expression, if General.VisibilityMode is set to 0 or 1 (char-expression can for example be "*").
< Recursive > Show { Point | Line | Surface | Volume { expression-list }; ... }
Show the entities listed in expression-list, if General.VisibilityMode is set to 0 or 1.
Show char-expression;
Show the entity char-expression, if General.VisibilityMode is set to 0 or 1 (char-expression can for example be "*").


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5.2 Geometry options

The list of all the options that control the behavior of geometry commands, as well as the way geometrical entities are handled in the GUI, is give in Geometry options list.


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6 Mesh module

Gmsh's mesh module regroups several 1D, 2D and 3D meshing algorithms, all producing grids conforming in the sense of finite elements (see Mesh):

All meshes can be subdivided to generate fully quadrangular or fully hexahedral meshes with the Mesh.SubdivisionAlgorihm option (see Mesh options list). However, beware that the quality of subdivided elements initially generated with an unstructured algorithm can be quite poor.


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6.1 Choosing the right unstructured algorithm

Gmsh currently provides a choice between three 2D unstructured algorithms and between two 3D unstructured algorithms. Each algorithm has its own advantages and disadvantages.

For all 2D unstructured algorithms a Delaunay mesh that contains all the points of the 1D mesh is initially constructed using a divide-and-conquer algorithm8. Missing edges are recovered using edge swaps9. After this initial step three different algorithms can be applied to generate the final mesh:

  1. The “MeshAdapt” algorithm10 is based on local mesh modifications. This technique makes use of edge swaps, splits, and collapses: long edges are split, short edges are collapsed, and edges are swapped if a better geometrical configuration is obtained.
  2. The “Delaunay” algorithm is inspired by the work of the GAMMA team at INRIA11. New points are inserted sequentially at the circumcenter of the element that has the largest adimensional circumradius. The mesh is then reconnected using an anisotropic Delaunay criterion.
  3. The “Frontal” algorithm is inspired by the work of S. Rebay12.

These algorithms can be ranked as follows:

                   Robustness        Performance      Element quality
     MeshAdapt         1                  3                 2
     Delaunay          2                  1                 2
     Frontal           3                  2                 1

For very complex curved surfaces the “MeshAdapt” algorithm is the best choice. When high element quality is important, the “Frontal” algorithm should be tried. For very large meshes of plane surfaces the “Delaunay” algorithm is the fastest.

The “Automatic” algorithm tries to select the best algorithm automatically for each surface in the model. As of Gmsh 2.8, the “Automatic” algorithm selects “Delaunay” for plane surfaces and “MeshAdapt” for all other surfaces.

In 3D two unstructured algorithms are available:

  1. The “Delaunay” algorithm is split into two separate steps. First, an initial mesh of the union of all the volumes in the model is performed using H. Si's Tetgen algorithm13. Then a three-dimensional version of the 2D Delaunay algorithm described above is applied.
  2. The “Frontal” algorithm uses J. Schoeberl's Netgen algorithm 14.

The “Delaunay” algorithm is the most robust and the fastest, and is the only one that supports the Field mechanism to specify element sizes (see Specifying mesh element sizes). However, this algorithm will sometimes modify the surface mesh, and is thus not suitable for producing hybrid structured/unstructured grids. In that case the “Frontal” algorithm should be preferred. The quality of the elements produced by both algorithms is comparable. If element quality is important the mesh optimizer(s) should be applied.


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6.2 Elementary vs. physical entities

If only elementary geometrical entities are defined (or if the Mesh.SaveAll option is set; see Mesh options list), the grid produced by the mesh module will be saved “as is”. That is, all the elements in the grid will be saved using the identification number of the elementary entities they discretize as their elementary region number (and 0 as their physical region number15; File formats). This can sometimes be inconvenient:

To remedy these problems, the geometry module (see Geometry module) introduces the notion of “physical” entities (also called “physical groups”). The purpose of physical entities is to assemble elementary entities into larger, possibly overlapping groups, and to control the orientation of the elements in these groups. The introduction of physical entities in large models usually greatly facilitates the manipulation of the model (e.g., using `Tools->Visibility' in the GUI) and the interfacing with external solvers.

In the MSH file format (see File formats), if physical entities are defined, the output mesh only contains those elements that belong to physical entities. Other file formats each treat physical entities in slightly different ways, depending on their capability to define groups.

In all cases, Gmsh reindexes the mesh vertices and elements so that they are numbered in a continuous sequence in the output files. Note that the numbers displayed on screen after mesh generation thus usually differ from the ones saved in the mesh files. To check the actual numbers saved in the output file just load the file back using `File->Open'.


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6.3 Mesh commands

The mesh module commands mostly permit to modify the mesh element sizes and specify structured grid parameters. The actual mesh “actions” (i.e., “mesh the lines”, “mesh the surfaces” and “mesh the volumes”) cannot be specified in the script files. They have to be given either in the GUI or on the command line (see Running Gmsh on your system, and Command-line options).


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6.3.1 Specifying mesh element sizes

There are three ways to specify the size of the mesh elements for a given geometry:

  1. First, if Mesh.CharacteristicLengthFromPoints is set (it is by default), you can simply specify desired mesh element sizes at the geometrical points of the model (with the Point command: see Points). The size of the mesh elements will then be computed by linearly interpolating these values on the initial mesh (see Mesh). This might sometimes lead to over-refinement in some areas, so that you may have to add “dummy” geometrical entities in the model in order to get the desired element sizes.

    This method works with all the algorithms implemented in the mesh module. The final element sizes are of course constrained by the structured algorithms for which the element sizes are explicitly specified (e.g., transfinite and extruded grids: see Structured grids).

  2. Second, if Mesh.CharacteristicLengthFromCurvature is set (it is not by default), the mesh will be adapted with respect to the curvature of the geometrical entities.
  3. Finally, you can specify general mesh size “fields”. Various fields exist:

    Fields are supported by all the algorithms except those based on Netgen. The list of available fields with their options is given below.

The three aforementioned methods can be used simultaneously, in which case the smallest element size is selected at any given point.

All element sizes are further constrained by the Mesh.CharacteristicLengthMin, Mesh.CharacteristicLengthMax and Mesh.CharacteristicLengthFactor options (see Mesh options list)

Here are the mesh commands that are related to the specification of mesh element sizes:

Characteristic Length { expression-list } = expression;
Modify the prescribed mesh element size of the points whose identification numbers are listed in expression-list. The new value is given by expression.
Field[expression] = string;
Create a new field (with id number expression), of type string.
Field[expression].string = char-expression | expression | expression-list;
Set the option string of the expression-th field.
Background Field = expression;
Select the expression-th field as the one used to compute element sizes. Only one background field can be given; if you want to combine several field, use the Min or Max field (see below).

Here is the list of all available fields with their associated options:

Attractor
Compute the distance from the nearest node in a list. It can also be used to compute the distance from curves, in which case each curve is replaced by NNodesByEdge equidistant nodes and the distance from those nodes is computed.
Options:
EdgesList
Indices of curves in the geometric model
type: list
default value: {}
FacesList
Indices of surfaces in the geometric model (Warning, this feature is still experimental. It might (read: will probably) give wrong results for complex surfaces)
type: list
default value: {}
FieldX
Id of the field to use as x coordinate.
type: integer
default value: -1
FieldY
Id of the field to use as y coordinate.
type: integer
default value: -1
FieldZ
Id of the field to use as z coordinate.
type: integer
default value: -1
NNodesByEdge
Number of nodes used to discretized each curve
type: integer
default value: 20
NodesList
Indices of nodes in the geometric model
type: list
default value: {}

AttractorAnisoCurve
Compute the distance from the nearest curve in a list. Then the mesh size can be specified independently in the direction normal to the curve and in the direction parallel to the curve (Each curve is replaced by NNodesByEdge equidistant nodes and the distance from those nodes is computed.)
Options:
EdgesList
Indices of curves in the geometric model
type: list
default value: {}
NNodesByEdge
Number of nodes used to discretized each curve
type: integer
default value: 20
dMax
Maxmium distance, above this distance from the curves, prescribe the maximum mesh sizes.
type: float
default value: 0.5
dMin
Minimum distance, bellow this distance from the curves, prescribe the minimum mesh sizes.
type: float
default value: 0.1
lMaxNormal
Maximum mesh size in the direction normal to the closest curve.
type: float
default value: 0.5
lMaxTangent
Maximum mesh size in the direction tangeant to the closest curve.
type: float
default value: 0.5
lMinNormal
Minimum mesh size in the direction normal to the closest curve.
type: float
default value: 0.05
lMinTangent
Minimum mesh size in the direction tangeant to the closest curve.
type: float
default value: 0.5

BoundaryLayer
hwall * ratio^(dist/hwall)
Options:
AnisoMax
Threshold angle for creating a mesh fan in the boundary layer
type: float
default value: 10000000000
EdgesList
Indices of curves in the geometric model for which a boundary layer is needed
type: list
default value: {}
FacesList
Indices of faces in the geometric model for which a boundary layer is needed
type: list
default value: {}
FanNodesList
Indices of vertices in the geometric model for which a fan is created
type: list
default value: {}
FansList
Indices of edges in the geometric model for which a fan is created
type: list
default value: {}
IntersectMetrics
Intersect metrics of all faces
type: integer
default value: 0
NodesList
Indices of nodes in the geometric model
type: list
default value: {}
Quads
Generate recombined elements in the boundary layer
type: integer
default value: 0
hfar
Element size far from the wall
type: float
default value: 1
hwall_n
Mesh Size Normal to the The Wall
type: float
default value: 0.1
hwall_t
Mesh Size Tangent to the Wall
type: float
default value: 0.5
ratio
Size Ratio Between Two Successive Layers
type: float
default value: 1.1
thickness
Maximal thickness of the boundary layer
type: float
default value: 0.01

Box
The value of this field is VIn inside the box, VOut outside the box. The box is given by

Xmin <= x <= XMax &&
YMin <= y <= YMax &&
ZMin <= z <= ZMax
Options:
VIn
Value inside the box
type: float
default value: 0
VOut
Value outside the box
type: float
default value: 0
XMax
Maximum X coordinate of the box
type: float
default value: 0
XMin
Minimum X coordinate of the box
type: float
default value: 0
YMax
Maximum Y coordinate of the box
type: float
default value: 0
YMin
Minimum Y coordinate of the box
type: float
default value: 0
ZMax
Maximum Z coordinate of the box
type: float
default value: 0
ZMin
Minimum Z coordinate of the box
type: float
default value: 0

Centerline
The value of this field is the distance to the centerline.

You should specify a fileName that contains the centerline. The centerline of a surface can be obtained with the open source software vmtk (http://www.vmtk.org/) using the following script:

vmtk vmtkcenterlines -seedselector openprofiles -ifile mysurface.stl -ofile centerlines.vtp –pipe vmtksurfacewriter -ifile centerlines.vtp -ofile centerlines.vtk

Options:
FileName
File name for the centerlines
type: string
default value: "centerlines.vtk"
closeVolume
Action: Create In/Outlet planar faces
type: integer
default value: 0
extrudeWall
Action: Extrude wall
type: integer
default value: 0
hLayer
Thickness (% of radius) of the extruded layer
type: float
default value: 0.3
hSecondLayer
Thickness (% of radius) of the second extruded layer
type: float
default value: 0.3
nbElemLayer
Number of mesh elements the extruded layer
type: integer
default value: 3
nbElemSecondLayer
Number of mesh elements the second extruded layer
type: integer
default value: 0
nbPoints
Number of mesh elements in a circle
type: integer
default value: 25
reMesh
Action: Cut the initial mesh in different mesh partitions using the centerlines
type: integer
default value: 0

Actions:

run
Run actions (closeVolume, extrudeWall, cutMesh)

Curvature
Compute the curvature of Field[IField]:

F = div(norm(grad(Field[IField])))
Options:
Delta
Step of the finite differences
type: float
default value: 0
IField
Field index
type: integer
default value: 1

Cylinder
The value of this field is VIn inside a frustrated cylinder, VOut outside. The cylinder is given by

||dX||^2 < R^2 &&
(X-X0).A < ||A||^2
dX = (X - X0) - ((X - X0).A)/(||A||^2) . A
Options:
Radius
Radius
type: float
default value: 0
VIn
Value inside the cylinder
type: float
default value: 0
VOut
Value outside the cylinder
type: float
default value: 0
XAxis
X component of the cylinder axis
type: float
default value: 0
XCenter
X coordinate of the cylinder center
type: float
default value: 0
YAxis
Y component of the cylinder axis
type: float
default value: 0
YCenter
Y coordinate of the cylinder center
type: float
default value: 0
ZAxis
Z component of the cylinder axis
type: float
default value: 1
ZCenter
Z coordinate of the cylinder center
type: float
default value: 0

Frustum
This field is an extended cylinder with inner (i) and outer (o) radiuseson both endpoints (1 and 2). Length scale is bilinearly interpolated betweenthese locations (inner and outer radiuses, endpoints 1 and 2)The field values for a point P are given by : u = P1P.P1P2/||P1P2|| r = || P1P - u*P1P2 || Ri = (1-u)*R1i + u*R2i Ro = (1-u)*R1o + u*R2o v = (r-Ri)/(Ro-Ri) lc = (1-v)*( (1-u)*v1i + u*v2i ) + v*( (1-u)*v1o + u*v2o ) where (u,v) in [0,1]x[0,1]
Options:
R1_inner
Inner radius of Frustum at endpoint 1
type: float
default value: 0
R1_outer
Outer radius of Frustum at endpoint 1
type: float
default value: 1
R2_inner
Inner radius of Frustum at endpoint 2
type: float
default value: 0
R2_outer
Outer radius of Frustum at endpoint 2
type: float
default value: 1
V1_inner
Element size at point 1, inner radius
type: float
default value: 0.1
V1_outer
Element size at point 1, outer radius
type: float
default value: 1
V2_inner
Element size at point 2, inner radius
type: float
default value: 0.1
V2_outer
Element size at point 2, outer radius
type: float
default value: 1
X1
X coordinate of endpoint 1
type: float
default value: 0
X2
X coordinate of endpoint 2
type: float
default value: 0
Y1
Y coordinate of endpoint 1
type: float
default value: 0
Y2
Y coordinate of endpoint 2
type: float
default value: 0
Z1
Z coordinate of endpoint 1
type: float
default value: 1
Z2
Z coordinate of endpoint 2
type: float
default value: 2.26338226046034e+146

Gradient
Compute the finite difference gradient of Field[IField]:

F = (Field[IField](X + Delta/2) - Field[IField](X - Delta/2)) / Delta
Options:
Delta
Finite difference step
type: float
default value: 0
IField
Field index
type: integer
default value: 1
Kind
Component of the gradient to evaluate: 0 for X, 1 for Y, 2 for Z, 3 for the norm
type: integer
default value: 0

Laplacian
Compute finite difference the Laplacian of Field[IField]:

F = G(x+d,y,z) + G(x-d,y,z) +
G(x,y+d,z) + G(x,y-d,z) +
G(x,y,z+d) + G(x,y,z-d) - 6 * G(x,y,z),

where G=Field[IField] and d=Delta
Options:
Delta
Finite difference step
type: float
default value: 0.1
IField
Field index
type: integer
default value: 1

LonLat
Evaluate Field[IField] in geographic coordinates (longitude, latitude):

F = Field[IField](atan(y/x), asin(z/sqrt(x^2+y^2+z^2))
Options:
FromStereo
if = 1, the mesh is in stereographic coordinates. xi = 2Rx/(R+z), eta = 2Ry/(R+z)
type: integer
default value: 0
IField
Index of the field to evaluate.
type: integer
default value: 1
RadiusStereo
radius of the sphere of the stereograpic coordinates
type: float
default value: 6371000

MathEval
Evaluate a mathematical expression. The expression can contain x, y, z for spatial coordinates, F0, F1, ... for field values, and and mathematical functions.
Options:
F
Mathematical function to evaluate.
type: string
default value: "F2 + Sin(z)"

Actions:

test
description blabla

MathEvalAniso
Evaluate a metric expression. The expressions can contain x, y, z for spatial coordinates, F0, F1, ... for field values, and and mathematical functions.
Options:
m11
element 11 of the metric tensor.
type: string
default value: "F2 + Sin(z)"
m12
element 12 of the metric tensor.
type: string
default value: "F2 + Sin(z)"
m13
element 13 of the metric tensor.
type: string
default value: "F2 + Sin(z)"
m22
element 22 of the metric tensor.
type: string
default value: "F2 + Sin(z)"
m23
element 23 of the metric tensor.
type: string
default value: "F2 + Sin(z)"
m33
element 33 of the metric tensor.
type: string
default value: "F2 + Sin(z)"

Max
Take the maximum value of a list of fields.
Options:
FieldsList
Field indices
type: list
default value: {}

MaxEigenHessian
Compute the maximum eigenvalue of the Hessian matrix of Field[IField], with the gradients evaluated by finite differences:

F = max(eig(grad(grad(Field[IField]))))
Options:
Delta
Step used for the finite differences
type: float
default value: 0
IField
Field index
type: integer
default value: 1

Mean
Simple smoother:

F = (G(x+delta,y,z) + G(x-delta,y,z) +
G(x,y+delta,z) + G(x,y-delta,z) +
G(x,y,z+delta) + G(x,y,z-delta) +
G(x,y,z)) / 7,

where G=Field[IField]
Options:
Delta
Distance used to compute the mean value
type: float
default value: 0.0001
IField
Field index
type: integer
default value: 0

Min
Take the minimum value of a list of fields.
Options:
FieldsList
Field indices
type: list
default value: {}

MinAniso
Take the intersection of a list of possibly anisotropic fields.
Options:
FieldsList
Field indices
type: list
default value: {}

Param
Evaluate Field IField in parametric coordinates:

F = Field[IField](FX,FY,FZ)

See the MathEval Field help to get a description of valid FX, FY and FZ expressions.
Options:
FX
X component of parametric function
type: string
default value: ""
FY
Y component of parametric function
type: string
default value: ""
FZ
Z component of parametric function
type: string
default value: ""
IField
Field index
type: integer
default value: 1

PostView
Evaluate the post processing view IView.
Options:
CropNegativeValues
return LC_MAX instead of a negative value (this option is needed for backward compatibility with the BackgroundMesh option
type: boolean
default value: 1
IView
Post-processing view index
type: integer
default value: 0

Restrict
Restrict the application of a field to a given list of geometrical curves, surfaces or volumes.
Options:
EdgesList
Curve indices
type: list
default value: {}
FacesList
Surface indices
type: list
default value: {}
IField
Field index
type: integer
default value: 1
RegionsList
Volume indices
type: list
default value: {}

Structured
Linearly interpolate between data provided on a 3D rectangular structured grid.

The format of the input file is:

Ox Oy Oz
Dx Dy Dz
nx ny nz
v(0,0,0) v(0,0,1) v(0,0,2) ...
v(0,1,0) v(0,1,1) v(0,1,2) ...
v(0,2,0) v(0,2,1) v(0,2,2) ...
... ... ...
v(1,0,0) ... ...

where O are the coordinates of the first node, D are the distances between nodes in each direction, n are the numbers of nodes in each direction, and v are the values on each node.
Options:
FileName
Name of the input file
type: path
default value: ""
OutsideValue
Value of the field outside the grid (only used if the "SetOutsideValue" option is true).
type: float
default value: 0
SetOutsideValue
True to use the "OutsideValue" option. If False, the last values of the grid are used.
type: boolean
default value: 0
TextFormat
True for ASCII input files, false for binary files (4 bite signed integers for n, double precision floating points for v, D and O)
type: boolean
default value: 0

Threshold
F = LCMin if Field[IField] <= DistMin,
F = LCMax if Field[IField] >= DistMax,
F = interpolation between LcMin and LcMax if DistMin < Field[IField] < DistMax
Options:
DistMax
Distance from entity after which element size will be LcMax
type: float
default value: 10
DistMin
Distance from entity up to which element size will be LcMin
type: float
default value: 1
IField
Index of the field to evaluate
type: integer
default value: 0
LcMax
Element size outside DistMax
type: float
default value: 1
LcMin
Element size inside DistMin
type: float
default value: 0.1
Sigmoid
True to interpolate between LcMin and LcMax using a sigmoid, false to interpolate linearly
type: boolean
default value: 0
StopAtDistMax
True to not impose element size outside DistMax (i.e., F = a very big value if Field[IField] > DistMax)
type: boolean
default value: 0


Next: , Previous: Specifying mesh element sizes, Up: Mesh commands

6.3.2 Structured grids

Extrude { expression-list } { extrude-list layers }
Extrudes both the geometry and the mesh using a translation (see Extrusions). The layers option determines how the mesh is extruded and has the following syntax:
          layers:
            Layers { expression } |
            Layers { { expression-list }, { expression-list } } |
            Recombine; ...
            QuadTriNoNewVerts <RecombLaterals>; |
            QuadTriAddVerts <RecombLaterals>; ...

In the first Layers form, expression gives the number of elements to be created in the (single) layer. In the second form, the first expression-list defines how many elements should be created in each extruded layer, and the second expression-list gives the normalized height of each layer (the list should contain a sequence of n numbers 0 < h1 < h2 < ... < hn <= 1). See t3.geo, for an example.

For line extrusions, the Recombine option will recombine triangles into quadrangles when possible. For surface extrusions, the Recombine option will recombine tetrahedra into prisms, hexahedra or pyramids.

Please note that, starting with Gmsh 2.0, region numbers cannot be specified explicitly anymore in Layers commands. Instead, as with all other geometry commands, you must use the automatically created entity identifier created by the extrusion command. For example, the following extrusion command will return the id of the new “top” surface in num[0] and the id of the new volume in num[1]:

          num[] = Extrude {0,0,1} { Surface{1}; Layers{10}; };

QuadTriNoNewVerts and QuadTriAddVerts allow to connect structured, extruded volumes containing quadrangle-faced elements to structured or unstructured tetrahedral volumes, by subdividing into triangles any quadrangles on boundary surfaces shared with tetrahedral volumes. (They have no effect for 1D or 2D extrusions.) QuadTriNoNewVerts subdivides any of the region's quad-faced 3D elements that touch these boundary triangles into pyramids, prisms, or tetrahedra as necessary, all WITHOUT adding new vertices. QuadTriAddVerts works in a simular way, but subdivides 3D elements touching the boundary triangles by adding a new vertex inside each element at the vertex-based centroid. Either method results in a structured extrusion with an outer layer of subdivided elements that interface the inner, unmodified elements to the triangle-meshed region boundaries.

In some rare cases, due to certain lateral boundary conditions, it may not be possible make a valid element subdivision with QuadTriNoNewVerts without adding additional vertices. In this case, an internal vertex is created at the vertex-based centroid of the element. The element is then divided using that vertex. When an internal vertex is created with QuadTriNoNewVerts, the user is alerted by a warning message sent for each instance; however, the mesh will still be valid and conformal.

Both QuadTriNoNewVerts and QuadTriAddVerts can be used with the optional RecombLaterals keyword. By default, the QuadTri algorithms will mesh any free laterals as triangles, if possible. RecombLaterals forces any free laterals to remain as quadrangles, if possible. Lateral surfaces between two QuadTri regions will always be meshed as quadrangles.

Note that the QuadTri algorithms will handle all potential meshing conflicts along the lateral surfaces of the extrusion. In other words, QuadTri will not subdivide a lateral that must remain as quadrangles, nor will it leave a lateral as quadrangles if it must be divided. The user should therefore feel free to mix different types of neighboring regions with a QuadTri meshed region; the mesh should work. However, be aware that the top surface of the QuadTri extrusion will always be meshed as triangles, unless it is extruded back onto the original source in a toroidal loop (a case which also works with QuadTri).

QuadTriNoNewVerts and QuadTriAddVerts may be used interchangeably, but QuadTriAddVerts often gives better element quality.

If the user wishes to interface a structured extrusion to a tetrahedral volume without modifying the original structured mesh, the user may create dedicated interface volumes around the structured geometry and apply a QuadTri algorithm to those volumes only.

Extrude { { expression-list }, { expression-list }, expression } { extrude-list layers }
Extrudes both the geometry and the mesh using a rotation (see Extrusions). The layers option is defined as above.
Extrude { { expression-list }, { expression-list }, { expression-list }, expression } { extrude-list layers }
Extrudes both the geometry and the mesh using a combined translation and rotation (see Extrusions). The layers option is defined as above.
Extrude { Surface { expression-list }; layers < Using Index[expr]; > < Using View[expr]; > < ScaleLastLayer; > }
Extrudes a boundary layer from the specified surfaces. If no view is specified, the boundary layer is created using gouraud-shaped (smoothed) normal field. Specifying a boundary layer index allows to extrude several independent boundary layers (with independent normal smoothing).

ScaleLastLayer scales the height of the last (top) layer of each normal's extrusion by the average length of the edges in all the source elements that contain the source vertex (actually, the average of the averages for each element–edges actually touching the source vertex are counted twice). This allows the height of the last layer to vary along with the size of the source elements in order to achieve better element quality. For example, in a boundary layer extruded with the Layers definition 'Layers{ {1,4,2}, {0.5, 0.6, 1.6} },' a source vertex adjacent to elements with an overall average edge length of 5.0 will extrude to have a last layer height = (1.6-0.6) * 5.0 = 5.0.

Transfinite Line { expression-list } | "*" = expression < Using Progression | Bump expression >;
Selects the lines in expression-list to be meshed with the 1D transfinite algorithm. The expression on the right hand side gives the number of nodes that will be created on the line (this overrides any other mesh element size prescription—see Specifying mesh element sizes). The optional argument `Using Progression expression' instructs the transfinite algorithm to distribute the nodes following a geometric progression (Progression 2 meaning for example that each line element in the series will be twice as long as the preceding one). The optional argument `Using Bump expression' instructs the transfinite algorithm to distribute the nodes with a refinement at both ends of the line.
Transfinite Surface { expression-list } | "*" < = { expression-list } > < Left | Right | Alternate | AlternateRight | AlternateLeft > ;
Selects surfaces to be meshed with the 2D transfinite algorithm. The expression-list on the right-hand-side should contain the identification numbers of three or four points on the boundary of the surface that define the corners of the transfinite interpolation. If no identification numbers are given, the transfinite algorithm will try to find the corners automatically. The optional argument specifies the way the triangles are oriented when the mesh is not recombined. (Alternate is a synonym for AlternateRight).
Transfinite Volume { expression-list } | "*" < = { expression-list } > ;
Selects five- or six-face volumes to be meshed with the 3D transfinite algorithm. The expression-list on the right-hand-side should contain the identification numbers of the six or eight points on the boundary of the volume that define the corners of the transfinite interpolation. If no identification numbers are given, the transfinite algorithm will try to find the corners automatically.
TransfQuadTri { expression-list } | "*";
Applies the transfinite QuadTri algorithm on the expression-list list of volumes ("*" can be used to apply TransfQuadTri to all existing volumes). A transfinite volume with any combination of recombined and un-recombined transfinite boundary surfaces is valid when meshed with TransfQuadTri. When applied to non-Transfinite volumes, TransfQuadTri has no effect on those volumes.


Previous: Structured grids, Up: Mesh commands

6.3.3 Miscellaneous

Here is a list of all other mesh commands currently available:

Point | Line { expression-list } In Surface { expression };
Embed the point(s) or line(s) in the given surface. The surface mesh will conform to the mesh of the point(s) or lines(s).
Surface { expression-list } In Volume { expression };
Embed the surface in the given volume. The volume mesh will conform to the mesh of the surface.
Periodic Line { expression-list } = { expression-list };
Force mesh of lines on the left-hand side (slaves) to match the mesh of the lines on the right-hand side (masters).
Periodic Surface expression { expression-list } = expression { expression-list };
Force mesh of the surface on the left-hand side (slave, with boundary edges specified between braces) to match the mesh of the surface on the right-hand side (master, with boundary edges specified between braces).
Coherence Mesh;
Removes all duplicate mesh vertices.
< Recursive > Color color-expression { Point | Line | Surface | Volume { expression-list }; ... }
Sets the mesh color of the entities in expression-list to color-expression.
< Recursive > Hide { Point | Line | Surface | Volume { expression-list }; ... }
Hides the mesh of the entities in expression-list, if General.VisibilityMode is set to 0 or 2.
Hide char-expression;
Hides the mesh of the entity char-expression, if General.VisibilityMode is set to 0 or 2 (char-expression can for example be "*").
Recombine Surface { expression-list } | "*" < = expression >;
Recombines the triangular meshes of the surfaces listed in expression-list into mixed triangular/quadrangular meshes. The optional expression on the right hand side specifies the maximum difference (in degrees) allowed between the largest angle of a quadrangle and a right angle (a value of 0 would only accept quadrangles with right angles; a value of 90 would allow degenerate quadrangles; default value is 45).
Reverse Line | Surface { expression-list } | "*" ;
Reverses the mesh of the given line(s) or surface(s).
Save char-expression;
Saves the mesh in a file named char-expression, using the current Mesh.Format (see Mesh options list). If the path in char-expression is not absolute, char-expression is appended to the path of the current file.
< Recursive > Show { Point | Line | Surface | Volume { expression-list }; ... }
Shows the mesh of the entities in expression-list, if General.VisibilityMode is set to 0 or 2.
Show char-expression;
Shows the mesh of the entity char-expression, if General.VisibilityMode is set to 0 or 2 (char-expression can for example be "*").
Smoother Surface { expression-list } = expression;
Sets number of elliptic smoothing steps for the surfaces listed in expression-list (smoothing only applies to transfinite meshes at the moment).
Homology ( { expression-list } ) { { expression-list } , { expression-list } };
Compute a basis representation for homology spaces after a mesh has been generated. The first expression-list is a list of dimensions whose homology bases are computed; if empty, all bases are computed. The second expression-list is a list physical groups that constitute the computation domain; if empty, the whole mesh is the domain. The third expression-list is a list of physical groups that constitute the relative subdomain of relative homology computation; if empty, absolute homology is computed. Resulting basis representation chains are stored as physical groups in the mesh.
Cohomology ( { expression-list } ) { { expression-list } , { expression-list } };
Similar to command Homology, but computes a basis representation for cohomology spaces instead.


Previous: Mesh commands, Up: Mesh module

6.4 Mesh options

The list of all the options that control the behavior of mesh commands, as well as the way meshes are displayed in the GUI, is given in Mesh options list.


Next: , Previous: Mesh module, Up: Top

7 Solver module

External solvers can be driven by Gmsh through the ONELAB http://www.onelab.info interface. To add a new solver in the solver module, you need to specify its name (Solver.Name0, Solver.Name1, etc.) and the path to the executable (Solver.Executable0, Solver.Executable1, etc.); see Solver options list).

The client-server API for the solver interface is defined in the onelab.h header. See utils/solvers/c++/solver.cpp for a simple example on how to use the ONELAB programming interface. See the sources of GetDP (http://geuz.org/getdp for a more comprehensive example.


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7.1 Solver options

The list of all the solver options is given in Solver options list.


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8 Post-processing module

Gmsh's post-processing module can handle multiple scalar, vector or tensor datasets along with the geometry and the mesh. The datasets can be given in several formats: in human-readable “parsed” format (these are just part of a standard input script, but are usually put in separate files with a .pos extension), in native MSH files (ASCII or binary files with .msh extensions: see File formats), or in standard third-party formats (like MED: http://www.code-aster.org/outils/med/).

Once loaded into Gmsh, scalar fields can be displayed as iso-value lines and surfaces or color maps, whereas vector fields can be represented either by three-dimensional arrows or by displacement maps. (Tensor fields are currently displayed as Von-Mises effective stresses, min/max eigenvalues, eigenvectors, ellipsis or ellipsoid. To display other (combinations of) components, you can use the Force scalar or Force vector options, or use Plugin(MathEval): see Post-processing plugins.)

In Gmsh's jargon, each dataset is called a “view”. Each view is given a name, and can be manipulated either individually (each view has its own button in the GUI and can be referred to by its index in a script) or globally (see the PostProcessing.Link option in Post-processing options list).

By default, Gmsh treats all post-processing views as three-dimensional plots, i.e., draws the scalar, vector and tensor primitives (points, lines, triangles, tetrahedra, etc.) in 3D space. But Gmsh can also represent each post-processing view containing scalar points as two-dimensional (“X-Y”) plots, either space- or time-oriented:

Although visualization is usually mostly an interactive task, Gmsh exposes all the post-processing commands and options to the user in its scripting language to permit a complete automation of the post-processing process (see e.g., t8.geo, and t9.geo).

The two following sections summarize all available post-processing commands and options. Most options apply to both 2D and 3D plots (colormaps, point/line sizes, interval types, time step selection, etc.), but some are peculiar to 3D (lightning, element selection, etc.) or 2D plots (abscissa labels, etc.). Note that 2D plots can be positioned explicitly inside the graphical window, or be automatically positioned in order to avoid overlaps.

Sample post-processing files in human-readable “parsed” format and in the native MSH file format are available in the tutorial directory of Gmsh's distribution (.pos and .msh files). The “parsed” format is defined in the next section (cf. the View command); the MSH format is defined in File formats.


Next: , Previous: Post-processing module, Up: Post-processing module

8.1 Post-processing commands

Alias View[expression];
Creates an alias of the expression-th post-processing view.

Note that Alias creates a logical duplicate of the view without actually duplicating the data in memory. This is very useful when you want multiple simultaneous renderings of the same large dataset (usually with different display options), but you cannot afford to store all copies in memory. If what you really want is multiple physical copies of the data, just merge the file containing the post-processing view multiple times.

AliasWithOptions View[expression];
Creates an alias of the expression-th post-processing view and copies all the options of the expression-th view to the new aliased view.
CopyOptions View[expression, expression];
Copy all the options from the first expression-th post-processing view to the second one.
Combine ElementsByViewName;
Combines all the post-processing views having the same name into new views. The combination is done “spatially”, i.e., simply by appending the elements at the end of the new views.
Combine ElementsFromAllViews | Combine Views;
Combines all the post-processing views into a single new view. The combination is done “spatially”, i.e., simply by appending the elements at the end of the new view.
Combine ElementsFromVisibleViews;
Combines all the visible post-processing views into a single new view. The combination is done “spatially”, i.e., simply by appending the elements at the end of the new view.
Combine TimeStepsByViewName | Combine TimeSteps;
Combines the data from all the post-processing views having the same name into new multi-time-step views. The combination is done “temporally”, i.e., as if the data in each view corresponds to a different time instant. The combination will fail if the meshes in all the views are not identical.
Combine TimeStepsFromAllViews;
Combines the data from all the post-processing views into a new multi-time-step view. The combination is done “temporally”, i.e., as if the data in each view corresponds to a different time instant. The combination will fail if the meshes in all the views are not identical.
Combine TimeStepsFromVisibleViews;
Combines the data from all the visible post-processing views into a new multi-time-step view. The combination is done “temporally”, i.e., as if the data in each view corresponds to a different time instant. The combination will fail if the meshes in all the views are not identical.
Delete View[expression];
Deletes (removes) the expression-th post-processing view. Note that post-processing view numbers start at 0.
Delete Empty Views;
Deletes (removes) all the empty post-processing views.
Background Mesh View[expression];
Applies the expression-th post-processing view as the current background mesh. Note that post-processing view numbers start at 0.
Plugin (string) . Run;
Executes the plugin string. The list of default plugins is given in Post-processing plugins.
Plugin (string) . string = expression | char-expression;
Sets an option for a given plugin. See Post-processing plugins, for a list of default plugins and t9.geo, for some examples.
Save View[expression] char-expression;
Saves the the expression-th post-processing view in a file named char-expression. If the path in char-expression is not absolute, char-expression is appended to the path of the current file.
View "string" { string < ( expression-list ) > { expression-list }; ... };
Creates a new post-processing view, named "string". This is an easy and quite powerful way to import post-processing data: all the values are expressions, you can embed datasets directly into your geometrical descriptions (see, e.g., t4.geo), the data can be easily generated “on-the-fly” (there is no header containing a priori information on the size of the dataset). The syntax is also very permissive, which makes it ideal for testing purposes.

However this “parsed format” is read by Gmsh's script parser, which makes it inefficient if there are many elements in the dataset. Also, there is no connectivity information in parsed views and all the elements are independent (all fields can be discontinuous), so a lot of information can be duplicated. For large datasets, you should thus use the mesh-based post-processing file format described in File formats, or use one of the standard formats like MED.

More explicitly, the syntax for a parsed View is the following

          View "string" {
            type ( list-of-coords ) { list-of-values }; ...
            < TIME { expression-list }; >
            < INTERPOLATION_SCHEME { val-coef-matrix } { val-exp-matrix }
                            < { geo-coef-matrix } { geo-exp-matrix } > ; >
          };

where the 47 object types that can be displayed are:

                                        type  #list-of-coords  #list-of-values
          --------------------------------------------------------------------
          Scalar point                  SP    3            1  * nb-time-steps
          Vector point                  VP    3            3  * nb-time-steps
          Tensor point                  TP    3            9  * nb-time-steps
          Scalar line                   SL    6            2  * nb-time-steps
          Vector line                   VL    6            6  * nb-time-steps
          Tensor line                   TL    6            18 * nb-time-steps
          Scalar triangle               ST    9            3  * nb-time-steps
          Vector triangle               VT    9            9  * nb-time-steps
          Tensor triangle               TT    9            27 * nb-time-steps
          Scalar quadrangle             SQ    12           4  * nb-time-steps
          Vector quadrangle             VQ    12           12 * nb-time-steps
          Tensor quadrangle             TQ    12           36 * nb-time-steps
          Scalar tetrahedron            SS    12           4  * nb-time-steps
          Vector tetrahedron            VS    12           12 * nb-time-steps
          Tensor tetrahedron            TS    12           36 * nb-time-steps
          Scalar hexahedron             SH    24           8  * nb-time-steps
          Vector hexahedron             VH    24           24 * nb-time-steps
          Tensor hexahedron             TH    24           72 * nb-time-steps
          Scalar prism                  SI    18           6  * nb-time-steps
          Vector prism                  VI    18           18 * nb-time-steps
          Tensor prism                  TI    18           54 * nb-time-steps
          Scalar pyramid                SY    15           5  * nb-time-steps
          Vector pyramid                VY    15           15 * nb-time-steps
          Tensor pyramid                TY    15           45 * nb-time-steps
          2D text                       T2    3            arbitrary
          3D text                       T3    4            arbitrary

The coordinates are given `by node', i.e.,

The ordering of the nodes is given in Node ordering.

The values are given by time step, by node and by component, i.e.:

          comp1-node1-time1, comp2-node1-time1, comp3-node1-time1,
          comp1-node2-time1, comp2-node2-time1, comp3-node2-time1,
          comp1-node3-time1, comp2-node3-time1, comp3-node3-time1,
          comp1-node1-time2, comp2-node1-time2, comp3-node1-time2,
          comp1-node2-time2, comp2-node2-time2, comp3-node2-time2,
          comp1-node3-time2, comp2-node3-time2, comp3-node3-time2,
          ...

For the 2D text objects, the two first expressions in list-of-coords give the X-Y position of the string in screen coordinates, measured from the top-left corner of the window. If the first (respectively second) expression is negative, the position is measured from the right (respectively bottom) edge of the window. If the value of the first (respectively second) expression is larger than 99999, the string is centered horizontally (respectively vertically). If the third expression is equal to zero, the text is aligned bottom-left and displayed using the default font and size. Otherwise, the third expression is converted into an integer whose eight lower bits give the font size, whose eight next bits select the font (the index corresponds to the position in the font menu in the GUI), and whose eight next bits define the text alignment (0=bottom-left, 1=bottom-center, 2=bottom-right, 3=top-left, 4=top-center, 5=top-right, 6=center-left, 7=center-center, 8=center-right).

For the 3D text objects, the three first expressions in list-of-coords give the XYZ position of the string in model (real world) coordinates. The fourth expression has the same meaning as the third expression in 2D text objects.

For both 2D and 3D text objects, the list-of-values can contain an arbitrary number of char-expressions.

The optional TIME list can contain a list of expressions giving the value of the time (or any other variable) for which an evolution was saved.

The optional INTERPOLATION_SCHEME lists can contain the interpolation matrices used for high-order adaptive visualization.

Let us assume that the approximation of the view's value over an element is written as a linear combination of d basis functions f[i], i=0, ..., d-1 (the coefficients being stored in list-of-values). Defining f[i] = Sum(j=0, ..., d-1) F[i][j] p[j], with p[j] = u^P[j][0] v^P[j][1] w^P[j][2] (u, v and w being the coordinates in the element's parameter space), then val-coef-matrix denotes the d x d matrix F and val-exp-matrix denotes the d x 3 matrix P.

In the same way, let us also assume that the coordinates x, y and z of the element are obtained through a geometrical mapping from parameter space as a linear combination of m basis functions g[i], i=0, ..., m-1 (the coefficients being stored in list-of-coords). Defining g[i] = Sum(j=0, ..., m-1) G[i][j] q[j], with q[j] = u^Q[j][0] v^Q[j][1] w^Q[j][2], then val-coef-matrix denotes the m x m matrix G and val-exp-matrix denotes the m x 3 matrix Q.

Here are for example the interpolation matrices for a first order quadrangle:

          INTERPOLATION_SCHEME
          {
            {1/4,-1/4, 1/4,-1/4},
            {1/4, 1/4,-1/4,-1/4},
            {1/4, 1/4, 1/4, 1/4},
            {1/4,-1/4,-1/4, 1/4}
          }
          {
            {0, 0, 0},
            {1, 0, 0},
            {0, 1, 0},
            {1, 1, 0}
          };


Next: , Previous: Post-processing commands, Up: Post-processing module

8.2 Post-processing plugins

Post-processing plugins permit to extend the functionality of Gmsh's post-processing module. The difference between regular post-processing options (see Post-processing options list) and post-processing plugins is that regular post-processing options only change the way the data is displayed, while post-processing plugins either create new post-processing views, or modify the data stored in a view (in a destructive, non-reversible way).

Plugins are available in the GUI by right-clicking on a view button (or by clicking on the black arrow next to the view button) and then selecting the `Plugin' submenu.

Here is the list of the plugins that are shipped by default with Gmsh:

Plugin(AnalyseCurvedMesh)
Plugin(AnalyseCurvedMesh) check the jacobian of all elements of dimension 'Dim' or the greater model dimension if 'Dim' is either <0 or >3.

Analysis : 0 do nothing +1 find invalid elements (*) +2 compute J_min and J_max of all elements and print some statistics

Effect (for *) : 0 do nothing +1 print a list of invalid elements +2 print some statistics +4 hide valid elements (for GUI)

MaxDepth = 0,1,... 0 : only sample the jacobian 1 : compute Bezier coefficients 2+ : execute a maximum of 1+ subdivision(s)

JacBreak = [0,1[ : if a value of the jacobian <= 'JacBreak' is found, the element is said to be invalid

BezBreak = [0,JacBreak[ : if all Bezier coefficients are > 'BezBreak', the element is said to be valid

Tolerance = R+ , << 1 : tolerance (relatively to J_min and J_max) used during the computation of J_min and J_max Numeric options:

Dim
Default value: -1
Analysis
Default value: 2
Effect (1)
Default value: 6
JacBreak (1)
Default value: 0
BezBreak (1)
Default value: 0
MaxDepth (1,2)
Default value: 20
Tolerance (2)
Default value: 0.001

Plugin(Annotate)
Plugin(Annotate) adds the text string `Text', in font `Font' and size `FontSize', in the view `View'. The string is aligned according to `Align'.

If `ThreeD' is equal to 1, the plugin inserts the string in model coordinates at the position (`X',`Y',`Z'). If `ThreeD' is equal to 0, the plugin inserts the string in screen coordinates at the position (`X',`Y').

If `View' < 0, the plugin is run on the current view.

Plugin(Annotate) is executed in-place for list-based datasets or creates a new view for other datasets. String options:

Text
Default value: "My Text"
Font
Default value: "Helvetica"
Align
Default value: "Left"
Numeric options:
X
Default value: 50
Y
Default value: 30
Z
Default value: 0
ThreeD
Default value: 0
FontSize
Default value: 14
View
Default value: -1

Plugin(Bubbles)
Plugin(Bubbles) constructs a geometry consisting of `bubbles' inscribed in the Voronoi of an input triangulation. `ShrinkFactor' allows to change the size of the bubbles. The plugin expects a triangulation in the `z = 0' plane to exist in the current model.

Plugin(Bubbles) creates one `.geo' file. String options:

OutputFile
Default value: "bubbles.geo"
Numeric options:
ShrinkFactor
Default value: 0

Plugin(Crack)
Plugin(Crack) creates a crack around the physical group `PhysicalGroup' of dimension `Dimension' (1 or 2). The plugin duplicates the vertices and the elements on the crack and stores them in a new discrete curve (`Dimension' = 1) or surface (`Dimension' = 2). The elements touching the crack on the negative side are modified to use the newly generated vertices.If `OpenBoundaryPhysicalGroup' is given (> 0), its vertices are duplicated and the crack will be left open on that (part of the) boundary. Otherwise, the lips of the crack are sealed, i.e., its vertices are not duplicated. Numeric options:
Dimension
Default value: 1
PhysicalGroup
Default value: 1
OpenBoundaryPhysicalGroup
Default value: 0

Plugin(Curl)
Plugin(Curl) computes the curl of the field in the view `View'.

If `View' < 0, the plugin is run on the current view.

Plugin(Curl) creates one new view. Numeric options:

View
Default value: -1

Plugin(CutBox)
Plugin(CutBox) cuts the view `View' with a rectangular box defined by the 4 points (`X0',`Y0',`Z0') (origin), (`X1',`Y1',`Z1') (axis of U), (`X2',`Y2',`Z2') (axis of V) and (`X3',`Y3',`Z3') (axis of W).

The number of points along U, V, W is set with the options `NumPointsU', `NumPointsV' and `NumPointsW'.

If `ConnectPoints' is zero, the plugin creates points; otherwise, the plugin generates hexahedra, quadrangles, lines or points depending on the values of `NumPointsU', `NumPointsV' and `NumPointsW'.

If `Boundary' is zero, the plugin interpolates the view inside the box; otherwise the plugin interpolates the view at its boundary.

If `View' < 0, the plugin is run on the current view.

Plugin(CutBox) creates one new view. Numeric options:

X0
Default value: 0
Y0
Default value: 0
Z0
Default value: 0
X1
Default value: 1
Y1
Default value: 0
Z1
Default value: 0
X2
Default value: 0
Y2
Default value: 1
Z2
Default value: 0
X3
Default value: 0
Y3
Default value: 0
Z3
Default value: 1
NumPointsU
Default value: 20
NumPointsV
Default value: 20
NumPointsW
Default value: 20
ConnectPoints
Default value: 1
Boundary
Default value: 1
View
Default value: -1

Plugin(CutGrid)
Plugin(CutGrid) cuts the view `View' with a rectangular grid defined by the 3 points (`X0',`Y0',`Z0') (origin), (`X1',`Y1',`Z1') (axis of U) and (`X2',`Y2',`Z2') (axis of V).

The number of points along U and V is set with the options `NumPointsU' and `NumPointsV'.

If `ConnectPoints' is zero, the plugin creates points; otherwise, the plugin generates quadrangles, lines or points depending on the values of `NumPointsU' and `NumPointsV'.

If `View' < 0, the plugin is run on the current view.

Plugin(CutGrid) creates one new view. Numeric options:

X0
Default value: 0
Y0
Default value: 0
Z0
Default value: 0
X1
Default value: 1
Y1
Default value: 0
Z1
Default value: 0
X2
Default value: 0
Y2
Default value: 1
Z2
Default value: 0
NumPointsU
Default value: 20
NumPointsV
Default value: 20
ConnectPoints
Default value: 1
View
Default value: -1

Plugin(CutParametric)
Plugin(CutParametric) cuts the view `View' with the parametric function (`X'(u,v), `Y'(u,v), `Z'(u,v)), using `NumPointsU' values of the parameter u in [`MinU', `MaxU'] and `NumPointsV' values of the parameter v in [`MinV', `MaxV'].

If `ConnectPoints' is set, the plugin creates surface or line elements; otherwise, the plugin generates points.

If `View' < 0, the plugin is run on the current view.

Plugin(CutParametric) creates one new view. String options:

X
Default value: "2 * Cos(u) * Sin(v)"
Y
Default value: "4 * Sin(u) * Sin(v)"
Z
Default value: "0.1 + 0.5 * Cos(v)"
Numeric options:
MinU
Default value: 0
MaxU
Default value: 6.2832
NumPointsU
Default value: 180
MinV
Default value: 0
MaxV
Default value: 6.2832
NumPointsV
Default value: 180
ConnectPoints
Default value: 0
View
Default value: -1

Plugin(CutPlane)
Plugin(CutPlane) cuts the view `View' with the plane `A'*X + `B'*Y + `C'*Z + `D' = 0.

If `ExtractVolume' is nonzero, the plugin extracts the elements on one side of the plane (depending on the sign of `ExtractVolume').

If `View' < 0, the plugin is run on the current view.

Plugin(CutPlane) creates one new view. Numeric options:

A
Default value: 1
B
Default value: 0
C
Default value: 0
D
Default value: -0.01
ExtractVolume
Default value: 0
RecurLevel
Default value: 4
TargetError
Default value: 0
View
Default value: -1

Plugin(CutSphere)
Plugin(CutSphere) cuts the view `View' with the sphere (X-`Xc')^2 + (Y-`Yc')^2 + (Z-`Zc')^2 = `R'^2.

If `ExtractVolume' is nonzero, the plugin extracts the elements inside (if `ExtractVolume' < 0) or outside (if `ExtractVolume' > 0) the sphere.

If `View' < 0, the plugin is run on the current view.

Plugin(CutSphere) creates one new view. Numeric options:

Xc
Default value: 0
Yc
Default value: 0
Zc
Default value: 0
R
Default value: 0.25
ExtractVolume
Default value: 0
RecurLevel
Default value: 4
TargetError
Default value: 0
View
Default value: -1

Plugin(DiscretizationError)
Plugin(DiscretizationError) computes the error between the mesh and the geometry. It does so by supersampling the elements and computing the distance between the supersampled points dans their projection on the geometry. Numeric options:
SuperSamplingNodes
Default value: 10

Plugin(Distance)
Plugin(Distance) computes distances to physical entities in a mesh.

Define the physical entities to which the distance is computed. If Point=0, Line=0, and Surface=0, then the distance is computed to all the boundaries of the mesh (edges in 2D and faces in 3D).

Computation<0. computes the geometrical euclidian distance (warning: different than the geodesic distance), and Computation=a>0.0 solves a PDE on the mesh with the diffusion constant mu = a*bbox, with bbox being the max size of the bounding box of the mesh (see paper Legrand 2006).

Min Scale and max Scale, scale the distance function. If min Scale<0 and max Scale<0, then no scaling is applied to the distance function.

Plugin(Distance) creates a new distance view and also saves the view in the fileName.pos file. String options:

Filename
Default value: "distance.pos"
Numeric options:
PhysPoint
Default value: 0
PhysLine
Default value: 0
PhysSurface
Default value: 0
Computation
Default value: -1
MinScale
Default value: -1
MaxScale
Default value: -1
Orthogonal
Default value: -1

Plugin(Divergence)
Plugin(Divergence) computes the divergence of the field in the view `View'.

If `View' < 0, the plugin is run on the current view.

Plugin(Divergence) creates one new view. Numeric options:

View
Default value: -1

Plugin(Eigenvalues)
Plugin(Eigenvalues) computes the three real eigenvalues of each tensor in the view `View'.

If `View' < 0, the plugin is run on the current view.

Plugin(Eigenvalues) creates three new scalar views. Numeric options:

View
Default value: -1

Plugin(Eigenvectors)
Plugin(Eigenvectors) computes the three (right) eigenvectors of each tensor in the view `View' and sorts them according to the value of the associated eigenvalues.

If `ScaleByEigenvalues' is set, each eigenvector is scaled by its associated eigenvalue. The plugin gives an error if the eigenvectors are complex.

If `View' < 0, the plugin is run on the current view.

Plugin(Eigenvectors) creates three new vector view. Numeric options:

ScaleByEigenvalues
Default value: 1
View
Default value: -1

Plugin(ExtractEdges)
Plugin(ExtractEdges) extracts sharp edges from a triangular mesh.

Plugin(ExtractEdges) creates one new view. Numeric options:

Angle
Default value: 40
IncludeBoundary
Default value: 1

Plugin(ExtractElements)
Plugin(ExtractElements) extracts some elements from the view `View'. If `MinVal' != `MaxVal', it extracts the elements whose `TimeStep'-th values (averaged by element) are comprised between `MinVal' and `MaxVal'. If `Visible' != 0, it extracts visible elements.

If `View' < 0, the plugin is run on the current view.

Plugin(ExtractElements) creates one new view. Numeric options:

MinVal
Default value: 0
MaxVal
Default value: 0
TimeStep
Default value: 0
Visible
Default value: 1
Dimension
Default value: -1
View
Default value: -1

Plugin(FaultZone)
Plugin(FaultZone) convert all the embedded lines of an existing surfacic mesh to flat quadrangles. Flat quadrangles represent joint elements suitable to model a fault zone with Code_Aster.

`SurfaceTag' must be an existing plane surface containing embedded lines. Embedded lines must have been added to the surface via the command Line In Surface. The surface must be meshed with quadratic incomplete elements.

`Thickness' is the thichness of the flat quadrangles. Set a value different to zero can be helpfull to check the connectivity.

`Prefix' is the prefix of the name of physicals containing the new embedded. All physicals containing embedded lines are replaced by physicals containing the coresponding joint elements. String options:

Prefix
Default value: "FAMI_"
Numeric options:
SurfaceTag
Default value: 1
Thickness
Default value: 0

Plugin(FieldFromAmplitudePhase)
Plugin(FieldFromAmplitudePhase) builds a complex field 'u' from amplitude 'a' (complex) and phase 'phi' given in two different 'Views' u = a * exp(k*phi), with k the wavenumber.

The result is to be interpolated in a sufficiently fine mesh: 'MeshFile'.

Plugin(FieldFromAmplitudePhase) generates one new view. String options:

MeshFile
Default value: "fine.msh"
Numeric options:
Wavenumber
Default value: 5
AmplitudeView
Default value: 0
PhaseView
Default value: 1

Plugin(Gradient)
Plugin(Gradient) computes the gradient of the field in the view `View'.

If `View' < 0, the plugin is run on the current view.

Plugin(Gradient) creates one new view. Numeric options:

View
Default value: -1

Plugin(HarmonicToTime)
Plugin(HarmonicToTime) takes the values in the time steps `RealPart' and `ImaginaryPart' of the view `View', and creates a new view containing

`View'[`RealPart'] * cos(p) - `View'[`ImaginaryPart'] * sin(p)

with p = 2*Pi*k/`NumSteps', k = 0, ..., `NumSteps'-1.

If `View' < 0, the plugin is run on the current view.

Plugin(HarmonicToTime) creates one new view. Numeric options:

RealPart
Default value: 0
ImaginaryPart
Default value: 1
NumSteps
Default value: 20
View
Default value: -1

Plugin(HomologyComputation)
Plugin(HomologyComputation) computes representative chains of basis elements of (relative) homology and cohomology spaces.

Define physical groups in order to specify the computation domain and the relative subdomain. Otherwise the whole mesh is the domain and the relative subdomain is empty.

Plugin(HomologyComputation) creates new views, one for each basis element. The resulting basis chains of desired dimension together with the mesh are saved to the given file. String options:

DomainPhysicalGroups
Default value: ""
SubdomainPhysicalGroups
Default value: ""
ReductionImmunePhysicalGroups
Default value: ""
DimensionOfChainsToSave
Default value: "0, 1, 2, 3"
Filename
Default value: "homology.msh"
Numeric options:
ComputeHomology
Default value: 1
ComputeCohomology
Default value: 0
HomologyPhysicalGroupsBegin
Default value: -1
CohomologyPhysicalGroupsBegin
Default value: -1
CreatePostProcessingViews
Default value: 1
ReductionOmit
Default value: 1
ReductionCombine
Default value: 3
PostProcessSimplify
Default value: 1
ReductionHeuristic
Default value: 1

Plugin(HomologyPostProcessing)
Plugin(HomologyPostProcessing) operates on representative basis chains of homology and cohomology spaces. Functionality:

1. (co)homology basis transformation: 'TransformationMatrix': Integer matrix of the transformation. 'PhysicalGroupsOfOperatedChains': (Co)chains of a (co)homology space basis to be transformed. Results a new (co)chain basis that is an integer cobination of the given basis.

2. Make basis representations of a homology space and a cohomology space compatible: 'PhysicalGroupsOfOperatedChains': Chains of a homology space basis. 'PhysicalGroupsOfOperatedChains2': Cochains of a cohomology space basis. Results a new basis for the homology space such that the incidence matrix of the new basis and the basis of the cohomology space is the identity matrix.

Options: 'PhysicalGroupsToTraceResults': Trace the resulting (co)chains to the given physical groups. 'PhysicalGroupsToProjectResults': Project the resulting (co)chains to the complement of the given physical groups. 'NameForResultChains': Post-processing view name prefix for the results. 'ApplyBoundaryOperatorToResults': Apply boundary operator to the resulting chains.

String options:

TransformationMatrix
Default value: "1, 0; 0, 1"
PhysicalGroupsOfOperatedChains
Default value: "1, 2"
PhysicalGroupsOfOperatedChains2
Default value: ""
PhysicalGroupsToTraceResults
Default value: ""
PhysicalGroupsToProjectResults
Default value: ""
NameForResultChains
Default value: "c"
Numeric options:
ApplyBoundaryOperatorToResults
Default value: 0

Plugin(Integrate)
Plugin(Integrate) integrates a scalar field over all the elements of the view `View' (if `Dimension' < 0), or over all elements of the prescribed dimension (if `Dimension' > 0). If the field is a vector field,the circulation/flux of the field over line/surface elements is calculated.

If `View' < 0, the plugin is run on the current view.

If `OverTime' = 1 , the plugin integrates the scalar view over time instead of over space.

Plugin(Integrate) creates one new view. Numeric options:

View
Default value: -1
OverTime
Default value: -1
Dimension
Default value: -1

Plugin(Isosurface)
Plugin(Isosurface) extracts the isosurface of value `Value' from the view `View', and draws the `OtherTimeStep'-th step of the view `OtherView' on this isosurface.

If `ExtractVolume' is nonzero, the plugin extracts the isovolume with values greater (if `ExtractVolume' > 0) or smaller (if `ExtractVolume' < 0) than the isosurface `Value'.

If `OtherTimeStep' < 0, the plugin uses, for each time step in `View', the corresponding time step in `OtherView'. If `OtherView' < 0, the plugin uses `View' as the value source.

If `View' < 0, the plugin is run on the current view.

Plugin(Isosurface) creates as many views as there are time steps in `View'. Numeric options:

Value
Default value: 0
ExtractVolume
Default value: 0
RecurLevel
Default value: 4
TargetError
Default value: 0
View
Default value: -1
OtherTimeStep
Default value: -1
OtherView
Default value: -1

Plugin(Lambda2)
Plugin(Lambda2) computes the eigenvalues Lambda(1,2,3) of the tensor (S_ik S_kj + Om_ik Om_kj), where S_ij = 0.5 (ui,j + uj,i) and Om_ij = 0.5 (ui,j - uj,i) are respectively the symmetric and antisymmetric parts of the velocity gradient tensor.

Vortices are well represented by regions where Lambda(2) is negative.

If `View' contains tensor elements, the plugin directly uses the tensors as the values of the velocity gradient tensor; if `View' contains vector elements, the plugin uses them as the velocities from which to derive the velocity gradient tensor.

If `View' < 0, the plugin is run on the current view.

Plugin(Lambda2) creates one new view. Numeric options:

Eigenvalue
Default value: 2
View
Default value: -1

Plugin(LongitudeLatitude)
Plugin(LongituteLatitude) projects the view `View' in longitude-latitude.

If `View' < 0, the plugin is run on the current view.

Plugin(LongituteLatitude) is executed in place. Numeric options:

View
Default value: -1

Plugin(MakeSimplex)
Plugin(MakeSimplex) decomposes all non-simplectic elements (quadrangles, prisms, hexahedra, pyramids) in the view `View' into simplices (triangles, tetrahedra).

If `View' < 0, the plugin is run on the current view.

Plugin(MakeSimplex) is executed in-place. Numeric options:

View
Default value: -1

Plugin(MathEval)
Plugin(MathEval) creates a new view using data from the time step `TimeStep' in the view `View'.

If only `Expression0' is given (and `Expression1', ..., `Expression8' are all empty), the plugin creates a scalar view. If `Expression0', `Expression1' and/or `Expression2' are given (and `Expression3', ..., `Expression8' are all empty) the plugin creates a vector view. Otherwise the plugin creates a tensor view.

In addition to the usual mathematical functions (Exp, Log, Sqrt, Sin, Cos, Fabs, etc.) and operators (+, -, *, /, ^), all expressions can contain:

- the symbols v0, v1, v2, ..., vn, which represent the n components in `View';

- the symbols w0, w1, w2, ..., wn, which represent the n components of `OtherView', at time step `OtherTimeStep';

- the symbols x, y and z, which represent the three spatial coordinates.

If `TimeStep' < 0, the plugin extracts data from all the time steps in the view.

If `View' < 0, the plugin is run on the current view.

Plugin(MathEval) creates one new view.If `PhysicalRegion' < 0, the plugin is run on all physical regions.

Plugin(MathEval) creates one new view. String options:

Expression0
Default value: "Sqrt(v0^2+v1^2+v2^2)"
Expression1
Default value: ""
Expression2
Default value: ""
Expression3
Default value: ""
Expression4
Default value: ""
Expression5
Default value: ""
Expression6
Default value: ""
Expression7
Default value: ""
Expression8
Default value: ""
Numeric options:
TimeStep
Default value: -1
View
Default value: -1
OtherTimeStep
Default value: -1
OtherView
Default value: -1
ForceInterpolation
Default value: 0
PhysicalRegion
Default value: -1

Plugin(MinMax)
Plugin(MinMax) computes the min/max of a view.

If `View' < 0, the plugin is run on the current view.

If `OverTime' = 1, calculates the min/max over space AND time

If `Argument' = 1, calculates the min/max AND the argmin/argmax

Plugin(MinMax) creates two new views. Numeric options:

View
Default value: -1
OverTime
Default value: 0
Argument
Default value: 0

Plugin(ModifyComponent)
Plugin(ModifyComponent) sets the `Component'-th component of the `TimeStep'-th time step in the view `View' to the expression `Expression'.

`Expression' can contain:

- the usual mathematical functions (Log, Sqrt, Sin, Cos, Fabs, ...) and operators (+, -, *, /, ^);

- the symbols x, y and z, to retrieve the coordinates of the current node;

- the symbols Time and TimeStep, to retrieve the current time and time step values;

- the symbol v, to retrieve the `Component'-th component of the field in `View' at the `TimeStep'-th time step;

- the symbols v0, v1, v2, ..., v8, to retrieve each component of the field in `View' at the `TimeStep'-th time step;

- the symbol w, to retrieve the `Component'-th component of the field in `OtherView' at the `OtherTimeStep'-th time step. If `OtherView' and `View' are based on different spatial grids, or if their data types are different, `OtherView' is interpolated onto `View';

- the symbols w0, w1, w2, ..., w8, to retrieve each component of the field in `OtherView' at the `OtherTimeStep'-th time step.

If `TimeStep' < 0, the plugin automatically loops over all the time steps in `View' and evaluates `Expression' for each one.

If `OtherTimeStep' < 0, the plugin uses `TimeStep' instead.

If `Component' < 0, the plugin automatically ops over all the components in the view and evaluates `Expression' for each one.

If `View' < 0, the plugin is run on the current view.

If `OtherView' < 0, the plugin uses `View' instead.

Plugin(ModifyComponent) is executed in-place. String options:

Expression
Default value: "v0 * Sin(x)"
Numeric options:
Component
Default value: -1
TimeStep
Default value: -1
View
Default value: -1
OtherTimeStep
Default value: -1
OtherView
Default value: -1
ForceInterpolation
Default value: 0

Plugin(ModulusPhase)
Plugin(ModulusPhase) interprets the time steps `realPart' and `imaginaryPart' in the view `View' as the real and imaginary parts of a complex field and replaces them with their corresponding modulus and phase.

If `View' < 0, the plugin is run on the current view.

Plugin(ModulusPhase) is executed in-place. Numeric options:

RealPart
Default value: 0
ImaginaryPart
Default value: 1
View
Default value: -1

Plugin(NearToFarField)
Plugin(NearToFarField) computes the far field pattern from the near electric E and magnetic H fields on a surface enclosing the radiating device (antenna).

Parameters: the wavenumber, the angular discretisation (phi in [0, 2*Pi] and theta in [0, Pi]) of the far field sphere and the indices of the views containing the complex-valued E and H fields. If `Normalize' is set, the far field is normalized to 1. If `dB' is set, the far field is computed in dB. If `NegativeTime' is set, E and H are assumed to have exp(-iwt) time dependency; otherwise they are assume to have exp(+iwt) time dependency. If `MatlabOutputFile' is given the raw far field data is also exported in Matlab format.

Plugin(NearToFarField) creates one new view. String options:

MatlabOutputFile
Default value: "farfield.m"
Numeric options:
Wavenumber
Default value: 1
PhiStart
Default value: 0
PhiEnd
Default value: 6.28319
NumPointsPhi
Default value: 60
ThetaStart
Default value: 0
ThetaEnd
Default value: 3.14159
NumPointsTheta
Default value: 30
EView
Default value: 0
HView
Default value: 1
Normalize
Default value: 1
dB
Default value: 1
NegativeTime
Default value: 0
RFar
Default value: 0

Plugin(NearestNeighbor)
Plugin(NearestNeighbor) computes the distance from each point in `View' to its nearest neighbor.

If `View' < 0, the plugin is run on the current view.

Plugin(NearestNeighbor) is executed in-place. Numeric options:

View
Default value: -1

Plugin(NewView)
Plugin(NewView) creates a new view from a mesh. Numeric options:
View
Default value: -1

Plugin(Particles)
Plugin(Particles) computes the trajectory of particules in the force field given by the `TimeStep'-th time step of a vector view `View'.

The plugin takes as input a grid defined by the 3 points (`X0',`Y0',`Z0') (origin), (`X1',`Y1',`Z1') (axis of U) and (`X2',`Y2',`Z2') (axis of V).

The number of particles along U and V that are to be transported is set with the options `NumPointsU' and `NumPointsV'. The equation

A2 * d^2X(t)/dt^2 + A1 * dX(t)/dt + A0 * X(t) = F

is then solved with the initial conditions X(t=0) chosen as the grid, dX/dt(t=0)=0, and with F interpolated from the vector view.

Time stepping is done using a Newmark scheme with step size `DT' and `MaxIter' maximum number of iterations.

If `View' < 0, the plugin is run on the current view.

Plugin(Particles) creates one new view containing multi-step vector points. Numeric options:

X0
Default value: 0
Y0
Default value: 0
Z0
Default value: 0
X1
Default value: 1
Y1
Default value: 0
Z1
Default value: 0
X2
Default value: 0
Y2
Default value: 1
Z2
Default value: 0
NumPointsU
Default value: 10
NumPointsV
Default value: 1
A2
Default value: 1
A1
Default value: 0
A0
Default value: 0
DT
Default value: 0.1
MaxIter
Default value: 100
TimeStep
Default value: 0
View
Default value: -1

Plugin(Probe)
Plugin(Probe) gets the value of the view `View' at the point (`X',`Y',`Z').

If `View' < 0, the plugin is run on the current view.

Plugin(Probe) creates one new view. Numeric options:

X
Default value: 0
Y
Default value: 0
Z
Default value: 0
View
Default value: -1

Plugin(Remove)
Plugin(Remove) removes the marked items from the view `View'.

If `View' < 0, the plugin is run on the current view.

Plugin(Remove) is executed in-place. Numeric options:

Text2D
Default value: 1
Text3D
Default value: 1
Points
Default value: 0
Lines
Default value: 0
Triangles
Default value: 0
Quadrangles
Default value: 0
Tetrahedra
Default value: 0
Hexahedra
Default value: 0
Prisms
Default value: 0
Pyramids
Default value: 0
Scalar
Default value: 1
Vector
Default value: 1
Tensor
Default value: 1
View
Default value: -1

Plugin(Scal2Vec)
Plugin(Scal2Vec) converts the scalar fields of 'ViewX', 'ViewY' and/or 'ViewZ' into a vectorial field. The new view 'NameNewView' contains it.

If the value of 'ViewX', 'ViewY' or 'ViewZ' is -1, the value of the vectorial field in the corresponding direction is 0. String options:

NameNewView
Default value: "NewView"
Numeric options:
ViewX
Default value: -1
ViewY
Default value: -1
ViewZ
Default value: -1

Plugin(SimplePartition)
Plugin(SimplePartition) partitions the current mesh into `NumSlices' slices, along the X-, Y- or Z-axis depending on the value of `Direction' (0,1,2). The plugin creates partition boundaries if `CreateBoundaries' is set. String options:
Mapping
Default value: "t"
Numeric options:
NumSlices
Default value: 4
Direction
Default value: 0
CreateBoundaries
Default value: 1

Plugin(Skin)
Plugin(Skin) extracts the boundary (skin) of the current mesh (if `FromMesh' = 1), or from the the view `View' (in which case it creates a new view). If `View' < 0 and `FromMesh' = 0, the plugin is run on the current view. If `Visible' is set, the plugin only extracts the skin of visible entities. Numeric options:
Visible
Default value: 1
FromMesh
Default value: 0
View
Default value: -1

Plugin(Smooth)
Plugin(Smooth) averages the values at the nodes of the view `View'.

If `View' < 0, the plugin is run on the current view.

Plugin(Smooth) is executed in-place. Numeric options:

View
Default value: -1

Plugin(SphericalRaise)
Plugin(SphericalRaise) transforms the coordinates of the elements in the view `View' using the values associated with the `TimeStep'-th time step.

Instead of elevating the nodes along the X, Y and Z axes as with the View[`View'].RaiseX, View[`View'].RaiseY and View[`View'].RaiseZ options, the raise is applied along the radius of a sphere centered at (`Xc', `Yc', `Zc').

To produce a standard radiation pattern, set `Offset' to minus the radius of the sphere the original data lives on.

If `View' < 0, the plugin is run on the current view.

Plugin(SphericalRaise) is executed in-place. Numeric options:

Xc
Default value: 0
Yc
Default value: 0
Zc
Default value: 0
Raise
Default value: 1
Offset
Default value: 0
TimeStep
Default value: 0
View
Default value: -1

Plugin(StreamLines)
Plugin(StreamLines) computes stream lines from the `TimeStep'-th time step of a vector view `View' and optionally interpolates the scalar view `OtherView' on the resulting stream lines.

The plugin takes as input a grid defined by the 3 points (`X0',`Y0',`Z0') (origin), (`X1',`Y1',`Z1') (axis of U) and (`X2',`Y2',`Z2') (axis of V).

The number of points along U and V that are to be transported is set with the options `NumPointsU' and `NumPointsV'. The equation

dX(t)/dt = V(x,y,z)

is then solved with the initial condition X(t=0) chosen as the grid and with V(x,y,z) interpolated on the vector view.

The time stepping scheme is a RK44 with step size `DT' and `MaxIter' maximum number of iterations.

If `TimeStep' < 0, the plugin tries to compute streamlines of the unsteady flow.

If `View' < 0, the plugin is run on the current view.

Plugin(StreamLines) creates one new view. This view contains multi-step vector points if `OtherView' < 0, or single-step scalar lines if `OtherView' >= 0. Numeric options:

X0
Default value: 0
Y0
Default value: 0
Z0
Default value: 0
X1
Default value: 1
Y1
Default value: 0
Z1
Default value: 0
X2
Default value: 0
Y2
Default value: 1
Z2
Default value: 0
NumPointsU
Default value: 10
NumPointsV
Default value: 1
DT
Default value: 0.1
MaxIter
Default value: 100
TimeStep
Default value: 0
View
Default value: -1
OtherView
Default value: -1

Plugin(Tetrahedralize)
Plugin(Tetrahedralize) tetrahedralizes the points in the view `View'.

If `View' < 0, the plugin is run on the current view.

Plugin(Tetrahedralize) creates one new view. Numeric options:

View
Default value: -1

Plugin(Transform)
Plugin(Transform) transforms the homogeneous node coordinates (x,y,z,1) of the elements in the view `View' by the matrix

[`A11' `A12' `A13' `Tx'] [`A21' `A22' `A23' `Ty'] [`A31' `A32' `A33' `Tz'].

If `SwapOrientation' is set, the orientation of the elements is reversed.

If `View' < 0, the plugin is run on the current view.

Plugin(Transform) is executed in-place. Numeric options:

A11
Default value: 1
A12
Default value: 0
A13
Default value: 0
A21
Default value: 0
A22
Default value: 1
A23
Default value: 0
A31
Default value: 0
A32
Default value: 0
A33
Default value: 1
Tx
Default value: 0
Ty
Default value: 0
Tz
Default value: 0
SwapOrientation
Default value: 0
View
Default value: -1

Plugin(Triangulate)
Plugin(Triangulate) triangulates the points in the view `View', assuming that all the points belong to a surface that can be projected one-to-one onto a plane.

If `View' < 0, the plugin is run on the current view.

Plugin(Triangulate) creates one new view. Numeric options:

View
Default value: -1

Plugin(Warp)
Plugin(Warp) transforms the elements in the view `View' by adding to their node coordinates the vector field stored in the `TimeStep'-th time step of the view `OtherView', scaled by `Factor'.

If `View' < 0, the plugin is run on the current view.

If `OtherView' < 0, the vector field is taken as the field of surface normals multiplied by the `TimeStep' value in `View'. (The smoothing of the surface normals is controlled by the `SmoothingAngle' parameter.)

Plugin(Warp) is executed in-place. Numeric options:

Factor
Default value: 1
TimeStep
Default value: 0
SmoothingAngle
Default value: 180
View
Default value: -1
OtherView
Default value: -1


Previous: Post-processing plugins, Up: Post-processing module

8.3 Post-processing options

General post-processing option names have the form `PostProcessing.string'. Options peculiar to post-processing views take two forms.

  1. options that should apply to all views can be set through `View.string', before any view is loaded;
  2. options that should apply only to the n-th view take the form `View[n].string' (n = 0, 1, 2, ...), after the n-th view is loaded.

The list of all post-processing and view options is given in Post-processing options list. See t8.geo, and t9.geo, for some examples.


Next: , Previous: Post-processing module, Up: Top

9 File formats

This chapter describes Gmsh's native “MSH” file format, used to store meshes and associated post-processing datasets. The MSH format exists in two flavors: ASCII and binary. The format has a version number (currently: 2.2) that is independent of Gmsh's main version number.

(Remember that for small post-processing datasets you can also use human-readable “parsed” post-processing views, as described in Post-processing commands. Such “parsed” views do not require an underlying mesh, and can therefore be easier to use in some cases.)


Next: , Previous: File formats, Up: File formats

9.1 MSH ASCII file format

The MSH ASCII file format contains one mandatory section giving information about the file ($MeshFormat), followed by several optional sections defining the nodes ($Nodes), elements ($Elements), region names ($PhysicalName), periodicity relations ($Periodic) and post-processing datasets ($NodeData, $ElementData, $ElementNodeData).

When $Elements are given, $Nodes should also be provided, before the $Elements section. Currently only one $Nodes and one $Elements section are allowed per file. (This might/will change in the future.)

Important note about efficiency. Node and element tags can be "sparse", i.e., do not have to constitute a continuous list of indexes starting at 1. However, using non-continuous tags will lead to performance degradation. For meshes, non-continuous indexing forces Gmsh to use a map instead of a vector to access nodes and elements. The performance hit is on speed. For post-processing datasets, which always use vectors to access data, the performance hit is on memory. A NodeData with two nodes, tagged 1 and 1000000, will allocate a (mostly empty) vector of 1000000 elements.

Any section with an unrecognized header is simply ignored: you can thus add comments in a .msh file by putting them e.g. inside a $Comments/$EndComments section.

Sections can be repeated in the same file, and post-processing sections can be put into separate files (e.g. one file per time step). Nodes are assumed to be defined before elements.

The format is defined as follows:

     $MeshFormat
     version-number file-type data-size
     $EndMeshFormat
     $Nodes
     number-of-nodes
     node-number x-coord y-coord z-coord
     ...
     $EndNodes
     $Elements
     number-of-elements
     elm-number elm-type number-of-tags < tag > ... node-number-list
     ...
     $EndElements
     $Periodic
     number-of-periodic-entities
     dimension slave-entity-tag master-entity-tag
     number-of-nodes
     slave-node-number master-node-number
     ...
     $EndPeriodic
     $PhysicalNames
     number-of-names
     physical-dimension physical-number "physical-name"
     ...
     $EndPhysicalNames
     $NodeData
     number-of-string-tags
     < "string-tag" >
     ...
     number-of-real-tags
     < real-tag >
     ...
     number-of-integer-tags
     < integer-tag >
     ...
     node-number value ...
     ...
     $EndNodeData
     $ElementData
     number-of-string-tags
     < "string-tag" >
     ...
     number-of-real-tags
     < real-tag >
     ...
     number-of-integer-tags
     < integer-tag >
     ...
     elm-number value ...
     ...
     $EndElementData
     $ElementNodeData
     number-of-string-tags
     < "string-tag" >
     ...
     number-of-real-tags
     < real-tag >
     ...
     number-of-integer-tags
     < integer-tag >
     ...
     elm-number number-of-nodes-per-element value ...
     ...
     $EndElementNodeData
     $InterpolationScheme
     "name"
     number-of-element-topologies
     elm-topology
     number-of-interpolation-matrices
     num-rows num-columns value ...
     ...
     $EndInterpolationScheme

where

version-number
is a real number equal to 2.2
file-type
is an integer equal to 0 in the ASCII file format.
data-size
is an integer equal to the size of the floating point numbers used in the file (currently only data-size = sizeof(double) is supported).
number-of-nodes
is the number of nodes in the mesh.
node-number
is the number (index) of the n-th node in the mesh; node-number must be a postive (non-zero) integer. Note that the node-numbers do not necessarily have to form a dense nor an ordered sequence.
x-coord y-coord z-coord
are the floating point values giving the X, Y and Z coordinates of the n-th node.
number-of-elements
is the number of elements in the mesh.
elm-number
is the number (index) of the n-th element in the mesh; elm-number must be a postive (non-zero) integer. Note that the elm-numbers do not necessarily have to form a dense nor an ordered sequence.
elm-type
defines the geometrical type of the n-th element:
1
2-node line.
2
3-node triangle.
3
4-node quadrangle.
4
4-node tetrahedron.
5
8-node hexahedron.
6
6-node prism.
7
5-node pyramid.
8
3-node second order line (2 nodes associated with the vertices and 1 with the edge).
9
6-node second order triangle (3 nodes associated with the vertices and 3 with the edges).
10
9-node second order quadrangle (4 nodes associated with the vertices, 4 with the edges and 1 with the face).
11
10-node second order tetrahedron (4 nodes associated with the vertices and 6 with the edges).
12
27-node second order hexahedron (8 nodes associated with the vertices, 12 with the edges, 6 with the faces and 1 with the volume).
13
18-node second order prism (6 nodes associated with the vertices, 9 with the edges and 3 with the quadrangular faces).
14
14-node second order pyramid (5 nodes associated with the vertices, 8 with the edges and 1 with the quadrangular face).
15
1-node point.
16
8-node second order quadrangle (4 nodes associated with the vertices and 4 with the edges).
17
20-node second order hexahedron (8 nodes associated with the vertices and 12 with the edges).
18
15-node second order prism (6 nodes associated with the vertices and 9 with the edges).
19
13-node second order pyramid (5 nodes associated with the vertices and 8 with the edges).
20
9-node third order incomplete triangle (3 nodes associated with the vertices, 6 with the edges)
21
10-node third order triangle (3 nodes associated with the vertices, 6 with the edges, 1 with the face)
22
12-node fourth order incomplete triangle (3 nodes associated with the vertices, 9 with the edges)
23
15-node fourth order triangle (3 nodes associated with the vertices, 9 with the edges, 3 with the face)
24
15-node fifth order incomplete triangle (3 nodes associated with the vertices, 12 with the edges)
25
21-node fifth order complete triangle (3 nodes associated with the vertices, 12 with the edges, 6 with the face)
26
4-node third order edge (2 nodes associated with the vertices, 2 internal to the edge)
27
5-node fourth order edge (2 nodes associated with the vertices, 3 internal to the edge)
28
6-node fifth order edge (2 nodes associated with the vertices, 4 internal to the edge)
29
20-node third order tetrahedron (4 nodes associated with the vertices, 12 with the edges, 4 with the faces)
30
35-node fourth order tetrahedron (4 nodes associated with the vertices, 18 with the edges, 12 with the faces, 1 in the volume)
31
56-node fifth order tetrahedron (4 nodes associated with the vertices, 24 with the edges, 24 with the faces, 4 in the volume)
92
64-node third order hexahedron (8 nodes associated with the vertices, 24 with the edges, 24 with the faces, 8 in the volume)
93
125-node fourth order hexahedron (8 nodes associated with the vertices, 36 with the edges, 54 with the faces, 27 in the volume)
See below for the ordering of the nodes.
number-of-tags
gives the number of integer tags that follow for the n-th element. By default, the first tag is the number of the physical entity to which the element belongs; the second is the number of the elementary geometrical entity to which the element belongs; the third is the number of mesh partitions to which the element belongs, followed by the partition ids (negative partition ids indicate ghost cells). A zero tag is equivalent to no tag. Gmsh and most codes using the MSH 2 format require at least the first two tags (physical and elementary tags).
node-number-list
is the list of the node numbers of the n-th element. The ordering of the nodes is given in Node ordering.
number-of-string-tags
gives the number of string tags that follow. By default the first string-tag is interpreted as the name of the post-processing view and the second as the name of the interpolation scheme. The interpolation scheme is provided in the $InterpolationScheme section (see below).
number-of-real-tags
gives the number of real number tags that follow. By default the first real-tag is interpreted as a time value associated with the dataset.
number-of-integer-tags
gives the number of integer tags that follow. By default the first integer-tag is interpreted as a time step index (starting at 0), the second as the number of field components of the data in the view (1, 3 or 9), the third as the number of entities (nodes or elements) in the view, and the fourth as the partition index for the view data (0 for no partition).
number-of-nodes-per-elements
gives the number of node values for an element in an element-based view.
value
is a real number giving the value associated with a node or an element. For NodeData (respectively ElementData) views, there are ncomp values per node (resp. per element), where ncomp is the number of field components. For ElementNodeData views, there are ncomp times number-of-nodes-per-elements values per element.
number-of-element-topologies
is the number of element topologies for which interpolation matrices are provided
elm-topology
is the id tag of a given element topology: 1 for points, 2 for lines, 3 for triangles, 4 for quadrangles, 5 for tetrahedra, 6 for pyramids, 7 for prisms, 8 for hexahedra, 9 for polygons and 10 for polyhedra.
number-of-interpolation-matrices
is the number of interpolation matrices provided for this element topology. Currently you should provide 2 matrices, i.e., the matrices that specify how to interpolate the data (they have the same meaning as in Post-processing commands). The matrices are specified by 2 integers (num-rows and num-columns) followed by the values.

Below is a small example (a mesh consisting of two quadrangles with an associated nodal scalar dataset; the comments are not part of the actual file!):

     $MeshFormat
     2.2 0 8
     $EndMeshFormat
     $Nodes
     6                      six mesh nodes:
     1 0.0 0.0 0.0            node #1: coordinates (0.0, 0.0, 0.0)
     2 1.0 0.0 0.0            node #2: coordinates (1.0, 0.0, 0.0)
     3 1.0 1.0 0.0            etc.
     4 0.0 1.0 0.0
     5 2.0 0.0 0.0
     6 2.0 1.0 0.0
     $EndNodes
     $Elements
     2                      two elements:
     1 3 2 99 2 1 2 3 4       quad #1: type 3, physical 99, elementary 2, nodes 1 2 3 4
     2 3 2 99 2 2 5 6 3       quad #2: type 3, physical 99, elementary 2, nodes 2 5 6 3
     $EndElements
     $NodeData
     1                      one string tag:
     "A scalar view"          the name of the view ("A scalar view")
     1                      one real tag:
     0.0                      the time value (0.0)
     3                      three integer tags:
     0                        the time step (0; time steps always start at 0)
     1                        1-component (scalar) field
     6                        six associated nodal values
     1 0.0                  value associated with node #1 (0.0)
     2 0.1                  value associated with node #2 (0.1)
     3 0.2                  etc.
     4 0.0
     5 0.2
     6 0.4
     $EndNodeData


Next: , Previous: MSH ASCII file format, Up: File formats

9.2 MSH binary file format

The binary file format is similar to the ASCII format described above:

     $MeshFormat
     version-number file-type data-size
     one-binary
     $EndMeshFormat
     $Nodes
     number-of-nodes
     nodes-binary
     $EndNodes
     $Elements
     number-of-elements
     element-header-binary
     elements-binary
     element-header-binary
     elements-binary
     ...
     $EndElements
     
     [ all other sections are identical to ASCII, except that node-number,
       elm-number, number-of-nodes-per-element and values are written in
       binary format ]

where

version-number
is a real number equal to 2.2.
file-type
is an integer equal to 1.
data-size
has the same meaning as in the ASCII file format. Currently only data-size = sizeof(double) is supported.
one-binary
is an integer of value 1 written in binary form. This integer is used for detecting if the computer on which the binary file was written and the computer on which the file is read are of the same type (little or big endian).

Here is a pseudo C code to write one-binary:

          int one = 1;
          fwrite(&one, sizeof(int), 1, file);

number-of-nodes
has the same meaning as in the ASCII file format.
nodes-binary
is the list of nodes in binary form, i.e., a array of number-of-nodes * (4 + 3 * data-size) bytes. For each node, the first 4 bytes contain the node number and the next (3 * data-size) bytes contain the three floating point coordinates.

Here is a pseudo C code to write nodes-binary:

          for(i = 0; i < number_of_nodes; i++){
            fwrite(&num_i, sizeof(int), 1, file);
            double xyz[3] = {node_i_x, node_i_y, node_i_z};
            fwrite(xyz, sizeof(double), 3, file);
          }

number-of-elements
has the same meaning as in the ASCII file format.
element-header-binary
is a list of 3 integers in binary form, i.e., an array of (3 * 4) bytes: the first four bytes contain the type of the elements that follow (same as elm-type in the ASCII format), the next four contain the number of elements that follow, and the last four contain the number of tags per element (same as number-of-tags in the ASCII format).

Here is a pseudo C code to write element-header-binary:

          int header[3] = {elm_type, num_elm_follow, num_tags};
          fwrite(header, sizeof(int), 3, file);

elements-binary
is a list of elements in binary form, i.e., an array of “number of elements that follow” * (4 + number-of-tags * 4 + #node-number-list * 4) bytes. For each element, the first four bytes contain the element number, the next (number-of-tags * 4) contain the tags, and the last (#node-number-list * 4) contain the node indices.

Here is a pseudo C code to write elements-binary for triangles with the 2 standard tags (the physical and elementary regions):

          for(i = 0; i < number_of_triangles; i++){
            int data[6] = {num_i, physical, elementary,
                           node_i_1, node_i_2, node_i_3};
            fwrite(data, sizeof(int), 6, file);
          }


Next: , Previous: MSH binary file format, Up: File formats

9.3 Node ordering

Historically, Gmsh developers have started by implementing linear elements (lines, triangles, quads, tets, prisms and hexes). Then, second and sometimes third order elements have been hardcoded. We here distinguish “low order elements” that have been hardcoded initially and “high order elements” that have been coded in a general fashion, theoretically valid for any order.

9.3.1 Low order elements

For all mesh and post-processing file formats, the reference elements are defined as follows.

     Line:                   Line3:           Line4:
     
     0----------1 --> u      0-----2----1     0----2----3----1
     Triangle:               Triangle6:          Triangle9/10:          Triangle12/15:
     
     v
     ^                                                                   2
     |                                                                   | \
     2                       2                    2                      9   8
     |`\                     |`\                  | \                    |     \
     |  `\                   |  `\                7   6                 10 (14)  7
     |    `\                 5    `4              |     \                |         \
     |      `\               |      `\            8  (9)  5             11 (12) (13) 6
     |        `\             |        `\          |         \            |             \
     0----------1 --> u      0-----3----1         0---3---4---1          0---3---4---5---1
     Quadrangle:            Quadrangle8:            Quadrangle9:
     
           v
           ^
           |
     3-----------2          3-----6-----2           3-----6-----2
     |     |     |          |           |           |           |
     |     |     |          |           |           |           |
     |     +---- | --> u    7           5           7     8     5
     |           |          |           |           |           |
     |           |          |           |           |           |
     0-----------1          0-----4-----1           0-----4-----1
     Tetrahedron:                          Tetrahedron10:
     
                        v
                      .
                    ,/
                   /
                2                                     2
              ,/|`\                                 ,/|`\
            ,/  |  `\                             ,/  |  `\
          ,/    '.   `\                         ,6    '.   `5
        ,/       |     `\                     ,/       8     `\
      ,/         |       `\                 ,/         |       `\
     0-----------'.--------1 --> u         0--------4--'.--------1
      `\.         |      ,/                 `\.         |      ,/
         `\.      |    ,/                      `\.      |    ,9
            `\.   '. ,/                           `7.   '. ,/
               `\. |/                                `\. |/
                  `3                                    `3
                     `\.
                        ` w
     Hexahedron:             Hexahedron20:          Hexahedron27:
     
            v
     3----------2            3----13----2           3----13----2
     |\     ^   |\           |\         |\          |\         |\
     | \    |   | \          | 15       | 14        |15    24  | 14
     |  \   |   |  \         9  \       11 \        9  \ 20    11 \
     |   7------+---6        |   7----19+---6       |   7----19+---6
     |   |  +-- |-- | -> u   |   |      |   |       |22 |  26  | 23|
     0---+---\--1   |        0---+-8----1   |       0---+-8----1   |
      \  |    \  \  |         \  17      \  18       \ 17    25 \  18
       \ |     \  \ |         10 |        12|        10 |  21    12|
        \|      w  \|           \|         \|          \|         \|
         4----------5            4----16----5           4----16----5
     Prism:                      Prism15:               Prism18:
     
                w
                ^
                |
                3                       3                      3
              ,/|`\                   ,/|`\                  ,/|`\
            ,/  |  `\               12  |  13              12  |  13
          ,/    |    `\           ,/    |    `\          ,/    |    `\
         4------+------5         4------14-----5        4------14-----5
         |      |      |         |      8      |        |      8      |
         |    ,/|`\    |         |      |      |        |    ,/|`\    |
         |  ,/  |  `\  |         |      |      |        |  15  |  16  |
         |,/    |    `\|         |      |      |        |,/    |    `\|
        ,|      |      |\        10     |      11       10-----17-----11
      ,/ |      0      | `\      |      0      |        |      0      |
     u   |    ,/ `\    |    v    |    ,/ `\    |        |    ,/ `\    |
         |  ,/     `\  |         |  ,6     `7  |        |  ,6     `7  |
         |,/         `\|         |,/         `\|        |,/         `\|
         1-------------2         1------9------2        1------9------2
     Pyramid:                     Pyramid13:                   Pyramid14:
     
                    4                            4                            4
                  ,/|\                         ,/|\                         ,/|\
                ,/ .'|\                      ,/ .'|\                      ,/ .'|\
              ,/   | | \                   ,/   | | \                   ,/   | | \
            ,/    .' | `.                ,/    .' | `.                ,/    .' | `.
          ,/      |  '.  \             ,7      |  12  \             ,7      |  12  \
        ,/       .' w |   \          ,/       .'   |   \          ,/       .'   |   \
      ,/         |  ^ |    \       ,/         9    |    11      ,/         9    |    11
     0----------.'--|-3    `.     0--------6-.'----3    `.     0--------6-.'----3    `.
      `\        |   |  `\    \      `\        |      `\    \     `\        |      `\    \
        `\     .'   +----`\ - \ -> v  `5     .'        10   \      `5     .' 13     10   \
          `\   |    `\     `\  \        `\   |           `\  \       `\   |           `\  \
            `\.'      `\     `\`          `\.'             `\`         `\.'             `\`
               1----------------2            1--------8-------2           1--------8-------2
                         `\
                            u

9.3.2 High order elements

The node ordering of a higher order (possibly curved) element is compatible with the numbering of low order element (it is a generalization). We number nodes in the following order:

The numbering for internal nodes is recursive, ie. the numbering follows that of the nodes of an embedded edge/face/volume of lower order. The higher order nodes are assumed to be equispaced. Edges and faces are numbered following the lowest order template that generates a single high-order on this edge/face. Furthermore, an edge is oriented from the vertex with the lowest to the highest index. The orientation of a face is such that the computed normal points outward; the starting point is the vertex with the lowest index.


Previous: Node ordering, Up: File formats

9.4 Legacy formats

This section describes Gmsh's older native file formats. Future versions of Gmsh will continue to support these formats, but we recommend that you do not use them in new applications.


Next: , Previous: Legacy formats, Up: Legacy formats

9.4.1 MSH file format version 1.0 (Legacy)

The MSH file format version 1.0 is Gmsh's old native mesh file format, now superseded by the format described in MSH ASCII file format. It is defined as follows:

     $NOD
     number-of-nodes
     node-number x-coord y-coord z-coord
     ...
     $ENDNOD
     $ELM
     number-of-elements
     elm-number elm-type reg-phys reg-elem number-of-nodes node-number-list
     ...
     $ENDELM

where

number-of-nodes
is the number of nodes in the mesh.
node-number
is the number (index) of the n-th node in the mesh; node-number must be a postive (non-zero) integer. Note that the node-numbers do not necessarily have to form a dense nor an ordered sequence.
x-coord y-coord z-coord
are the floating point values giving the X, Y and Z coordinates of the n-th node.
number-of-elements
is the number of elements in the mesh.
elm-number
is the number (index) of the n-th element in the mesh; elm-number must be a postive (non-zero) integer. Note that the elm-numbers do not necessarily have to form a dense nor an ordered sequence.
elm-type
defines the geometrical type of the n-th element:
1
2-node line.
2
3-node triangle.
3
4-node quadrangle.
4
4-node tetrahedron.
5
8-node hexahedron.
6
6-node prism.
7
5-node pyramid.
8
3-node second order line (2 nodes associated with the vertices and 1 with the edge).
9
6-node second order triangle (3 nodes associated with the vertices and 3 with the edges).
10
9-node second order quadrangle (4 nodes associated with the vertices, 4 with the edges and 1 with the face).
11
10-node second order tetrahedron (4 nodes associated with the vertices and 6 with the edges).
12
27-node second order hexahedron (8 nodes associated with the vertices, 12 with the edges, 6 with the faces and 1 with the volume).
13
18-node second order prism (6 nodes associated with the vertices, 9 with the edges and 3 with the quadrangular faces).
14
14-node second order pyramid (5 nodes associated with the vertices, 8 with the edges and 1 with the quadrangular face).
15
1-node point.
16
8-node second order quadrangle (4 nodes associated with the vertices and 4 with the edges).
17
20-node second order hexahedron (8 nodes associated with the vertices and 12 with the edges).
18
15-node second order prism (6 nodes associated with the vertices and 9 with the edges).
19
13-node second order pyramid (5 nodes associated with the vertices and 8 with the edges).
See below for the ordering of the nodes.
reg-phys
is the number of the physical entity to which the element belongs; reg-phys must be a postive integer, or zero. If reg-phys is equal to zero, the element is considered not to belong to any physical entity.
reg-elem
is the number of the elementary entity to which the element belongs; reg-elem must be a postive (non-zero) integer.
number-of-nodes
is the number of nodes for the n-th element. This is redundant, but kept for backward compatibility.
node-number-list
is the list of the number-of-nodes node numbers of the n-th element. The ordering of the nodes is given in Node ordering.


Next: , Previous: MSH file format version 1.0, Up: Legacy formats

9.4.2 POS ASCII file format (Legacy)

The POS ASCII file is Gmsh's old native post-processing format, now superseded by the format described in MSH ASCII file format. It is defined as follows:

     $PostFormat
     1.4 file-type data-size
     $EndPostFormat
     $View
     view-name nb-time-steps
     nb-scalar-points nb-vector-points nb-tensor-points
     nb-scalar-lines nb-vector-lines nb-tensor-lines
     nb-scalar-triangles nb-vector-triangles nb-tensor-triangles
     nb-scalar-quadrangles nb-vector-quadrangles nb-tensor-quadrangles
     nb-scalar-tetrahedra nb-vector-tetrahedra nb-tensor-tetrahedra
     nb-scalar-hexahedra nb-vector-hexahedra nb-tensor-hexahedra
     nb-scalar-prisms nb-vector-prisms nb-tensor-prisms
     nb-scalar-pyramids nb-vector-pyramids nb-tensor-pyramids
     nb-scalar-lines2 nb-vector-lines2 nb-tensor-lines2
     nb-scalar-triangles2 nb-vector-triangles2 nb-tensor-triangles2
     nb-scalar-quadrangles2 nb-vector-quadrangles2 nb-tensor-quadrangles2
     nb-scalar-tetrahedra2 nb-vector-tetrahedra2 nb-tensor-tetrahedra2
     nb-scalar-hexahedra2 nb-vector-hexahedra2 nb-tensor-hexahedra2
     nb-scalar-prisms2 nb-vector-prisms2 nb-tensor-prisms2
     nb-scalar-pyramids2 nb-vector-pyramids2 nb-tensor-pyramids2
     nb-text2d nb-text2d-chars nb-text3d nb-text3d-chars
     time-step-values
     < scalar-point-value > ... < vector-point-value > ...
         < tensor-point-value > ...
     < scalar-line-value > ... < vector-line-value > ...
         < tensor-line-value > ...
     < scalar-triangle-value > ... < vector-triangle-value > ...
         < tensor-triangle-value > ...
     < scalar-quadrangle-value > ... < vector-quadrangle-value > ...
         < tensor-quadrangle-value > ...
     < scalar-tetrahedron-value > ... < vector-tetrahedron-value > ...
         < tensor-tetrahedron-value > ...
     < scalar-hexahedron-value > ... < vector-hexahedron-value > ...
         < tensor-hexahedron-value > ...
     < scalar-prism-value > ... < vector-prism-value > ...
         < tensor-prism-value > ...
     < scalar-pyramid-value > ... < vector-pyramid-value > ...
         < tensor-pyramid-value > ...
     < scalar-line2-value > ... < vector-line2-value > ...
         < tensor-line2-value > ...
     < scalar-triangle2-value > ... < vector-triangle2-value > ...
         < tensor-triangle2-value > ...
     < scalar-quadrangle2-value > ... < vector-quadrangle2-value > ...
         < tensor-quadrangle2-value > ...
     < scalar-tetrahedron2-value > ... < vector-tetrahedron2-value > ...
         < tensor-tetrahedron2-value > ...
     < scalar-hexahedron2-value > ... < vector-hexahedron2-value > ...
         < tensor-hexahedron2-value > ...
     < scalar-prism2-value > ... < vector-prism2-value > ...
         < tensor-prism2-value > ...
     < scalar-pyramid2-value > ... < vector-pyramid2-value > ...
         < tensor-pyramid2-value > ...
     < text2d > ... < text2d-chars > ...
     < text3d > ... < text3d-chars > ...
     $EndView

where

file-type
is an integer equal to 0 in the ASCII file format.
data-size
is an integer equal to the size of the floating point numbers used in the file (usually, data-size = sizeof(double)).
view-name
is a string containing the name of the view (max. 256 characters).
nb-time-steps
is an integer giving the number of time steps in the view.
nb-scalar-points
nb-vector-points
...
are integers giving the number of scalar points, vector points, ..., in the view.
nb-text2d
nb-text3d
are integers giving the number of 2D and 3D text strings in the view.
nb-text2d-chars
nb-text3d-chars
are integers giving the total number of characters in the 2D and 3D strings.
time-step-values
is a list of nb-time-steps double precision numbers giving the value of the time (or any other variable) for which an evolution was saved.
scalar-point-value
vector-point-value
...
are lists of double precision numbers giving the node coordinates and the values associated with the nodes of the nb-scalar-points scalar points, nb-vector-points vector points, ..., for each of the time-step-values.

For example, vector-triangle-value is defined as:

          coord1-node1 coord1-node2 coord1-node3
          coord2-node1 coord2-node2 coord2-node3
          coord3-node1 coord3-node2 coord3-node3
          comp1-node1-time1 comp2-node1-time1 comp3-node1-time1
          comp1-node2-time1 comp2-node2-time1 comp3-node2-time1
          comp1-node3-time1 comp2-node3-time1 comp3-node3-time1
          comp1-node1-time2 comp2-node1-time2 comp3-node1-time2
          comp1-node2-time2 comp2-node2-time2 comp3-node2-time2
          comp1-node3-time2 comp2-node3-time2 comp3-node3-time2
          ...

The ordering of the nodes is given in Node ordering.

text2d
is a list of 4 double precision numbers:
          coord1 coord2 style index

where coord1 and coord2 give the X-Y position of the 2D string in screen coordinates (measured from the top-left corner of the window) and where index gives the starting index of the string in text2d-chars. If coord1 (respectively coord2) is negative, the position is measured from the right (respectively bottom) edge of the window. If coord1 (respectively coord2) is larger than 99999, the string is centered horizontally (respectively vertically). If style is equal to zero, the text is aligned bottom-left and displayed using the default font and size. Otherwise, style is converted into an integer whose eight lower bits give the font size, whose eight next bits select the font (the index corresponds to the position in the font menu in the GUI), and whose eight next bits define the text alignment (0=bottom-left, 1=bottom-center, 2=bottom-right, 3=top-left, 4=top-center, 5=top-right, 6=center-left, 7=center-center, 8=center-right).

text2d-chars
is a list of nb-text2d-chars characters. Substrings are separated with the null `\0' character.
text3d
is a list of 5 double precision numbers
          coord1 coord2 coord3 style index

where coord1, coord2 and coord3 give the XYZ coordinates of the string in model (real world) coordinates, index gives the starting index of the string in text3d-chars, and style has the same meaning as in text2d.

text3d-chars
is a list of nb-text3d-chars chars. Substrings are separated with the null `\0' character.


Previous: POS ASCII file format, Up: Legacy formats

9.4.3 POS binary file format (Legacy)

The POS binary file format is the same as the POS ASCII file format described in POS ASCII file format, except that:

  1. file-type equals 1.
  2. all lists of floating point numbers and characters are written in binary format
  3. there is an additional integer, of value 1, written before time-step-values. This integer is used for detecting if the computer on which the binary file was written and the computer on which the file is read are of the same type (little or big endian).

Here is a pseudo C code to write a post-processing file in binary format:

     int one = 1;
     
     fprintf(file, "$PostFormat\n");
     fprintf(file, "%g %d %d\n", 1.4, 1, sizeof(double));
     fprintf(file, "$EndPostFormat\n");
     fprintf(file, "$View\n");
     fprintf(file, "%s %d "
       "%d %d %d %d %d %d %d %d %d "
       "%d %d %d %d %d %d %d %d %d "
       "%d %d %d %d %d %d %d %d %d "
       "%d %d %d %d %d %d %d %d %d "
       "%d %d %d %d %d %d %d %d %d "
       "%d %d %d %d\n",
       view-name, nb-time-steps,
       nb-scalar-points, nb-vector-points, nb-tensor-points,
       nb-scalar-lines, nb-vector-lines, nb-tensor-lines,
       nb-scalar-triangles, nb-vector-triangles, nb-tensor-triangles,
       nb-scalar-quadrangles, nb-vector-quadrangles, nb-tensor-quadrangles,
       nb-scalar-tetrahedra, nb-vector-tetrahedra, nb-tensor-tetrahedra,
       nb-scalar-hexahedra, nb-vector-hexahedra, nb-tensor-hexahedra,
       nb-scalar-prisms, nb-vector-prisms, nb-tensor-prisms,
       nb-scalar-pyramids, nb-vector-pyramids, nb-tensor-pyramids,
       nb-scalar-lines2, nb-vector-lines2, nb-tensor-lines2,
       nb-scalar-triangles2, nb-vector-triangles2, nb-tensor-triangles2,
       nb-scalar-quadrangles2, nb-vector-quadrangles2, nb-tensor-quadrangles2,
       nb-scalar-tetrahedra2, nb-vector-tetrahedra2, nb-tensor-tetrahedra2,
       nb-scalar-hexahedra2, nb-vector-hexahedra2, nb-tensor-hexahedra2,
       nb-scalar-prisms2, nb-vector-prisms2, nb-tensor-prisms2,
       nb-scalar-pyramids2, nb-vector-pyramids2, nb-tensor-pyramids2,
       nb-text2d, nb-text2d-chars, nb-text3d, nb-text3d-chars);
     fwrite(&one, sizeof(int), 1, file);
     fwrite(time-step-values, sizeof(double), nb-time-steps, file);
     fwrite(all-scalar-point-values, sizeof(double), ..., file);
     ...
     fprintf(file, "\n$EndView\n");

In this pseudo-code, all-scalar-point-values is the array of double precision numbers containing all the scalar-point-value lists, put one after each other in order to form a long array of doubles. The principle is the same for all other kinds of values.


Next: , Previous: File formats, Up: Top

Appendix A Tutorial

The following examples introduce new features gradually, starting with t1.geo. The files corresponding to these examples are available in the tutorial directory of the Gmsh distribution.

To learn how to run Gmsh on your computer, see Running Gmsh on your system. Screencasts that show how to use the GUI are available on http://geuz.org/gmsh/screencasts/.


Next: , Previous: Tutorial, Up: Tutorial

A.1 t1.geo

/*********************************************************************
 *
 *  Gmsh tutorial 1
 *
 *  Variables, elementary entities (points, lines, surfaces), physical
 *  entities (points, lines, surfaces)
 *
 *********************************************************************/

// The simplest construction in Gmsh's scripting language is the
// `affectation'. The following command defines a new variable `lc':

lc = 1e-2;

// This variable can then be used in the definition of Gmsh's simplest
// `elementary entity', a `Point'. A Point is defined by a list of
// four numbers: three coordinates (X, Y and Z), and a characteristic
// length (lc) that sets the target element size at the point:

Point(1) = {0, 0, 0, lc};

// The distribution of the mesh element sizes is then obtained by
// interpolation of these characteristic lengths throughout the
// geometry. Another method to specify characteristic lengths is to
// use a background mesh (see `t7.geo' and `bgmesh.pos').

// We can then define some additional points as well as our first
// curve.  Curves are Gmsh's second type of elementery entities, and,
// amongst curves, straight lines are the simplest. A straight line is
// defined by a list of point numbers. In the commands below, for
// example, the line 1 starts at point 1 and ends at point 2:

Point(2) = {.1, 0,  0, lc} ;
Point(3) = {.1, .3, 0, lc} ;
Point(4) = {0,  .3, 0, lc} ;

Line(1) = {1,2} ;
Line(2) = {3,2} ;
Line(3) = {3,4} ;
Line(4) = {4,1} ;

// The third elementary entity is the surface. In order to define a
// simple rectangular surface from the four lines defined above, a
// line loop has first to be defined. A line loop is a list of
// connected lines, a sign being associated with each line (depending
// on the orientation of the line):

Line Loop(5) = {4,1,-2,3} ;

// We can then define the surface as a list of line loops (only one
// here, since there are no holes--see `t4.geo'):

Plane Surface(6) = {5} ;

// At this level, Gmsh knows everything to display the rectangular
// surface 6 and to mesh it. An optional step is needed if we want to
// associate specific region numbers to the various elements in the
// mesh (e.g. to the line segments discretizing lines 1 to 4 or to the
// triangles discretizing surface 6). This is achieved by the
// definition of `physical entities'. Physical entities will group
// elements belonging to several elementary entities by giving them a
// common number (a region number).

// We can for example group the points 1 and 2 into the physical
// entity 1:

Physical Point(1) = {1,2} ;

// Consequently, two punctual elements will be saved in the output
// mesh file, both with the region number 1. The mechanism is
// identical for line or surface elements:

MyLine = 99;
Physical Line(MyLine) = {1,2,4} ;

Physical Surface("My fancy surface label") = {6} ;

// All the line elements created during the meshing of lines 1, 2 and
// 4 will be saved in the output mesh file with the region number 99;
// and all the triangular elements resulting from the discretization
// of surface 6 will be given an automatic region number (100,
// associated with the label "My fancy surface label").

// Note that if no physical entities are defined, then all the
// elements in the mesh will be saved "as is", with their default
// orientation.


Next: , Previous: t1.geo, Up: Tutorial

A.2 t2.geo

/********************************************************************* 
 *
 *  Gmsh tutorial 2
 * 
 *  Includes, geometrical transformations, extruded geometries,
 *  elementary entities (volumes), physical entities (volumes)
 *
 *********************************************************************/

// We first include the previous tutorial file, in order to use it as
// a basis for this one:

Include "t1.geo";

// We can then add new points and lines in the same way as we did in
// `t1.geo':

Point(5) = {0, .4, 0, lc};
Line(5) = {4, 5};

// But Gmsh also provides tools to tranform (translate, rotate, etc.)
// elementary entities or copies of elementary entities. For example,
// the point 3 can be moved by 0.05 units to the left with:

Translate {-0.05, 0, 0} { Point{3}; }

// The resulting point can also be duplicated and translated by 0.1
// along the y axis:

Translate {0, 0.1, 0} { Duplicata{ Point{3}; } }

// This command created a new point with an automatically assigned
// id. This id can be obtained using the graphical user interface by
// hovering the mouse over it and looking at the bottom of the graphic
// window: in this case, the new point has id "6". Point 6 can then be
// used to create new entities, e.g.:

Line(7) = {3, 6};
Line(8) = {6, 5};
Line Loop(10) = {5,-8,-7,3};
Plane Surface(11) = {10};

// Using the graphical user interface to obtain the ids of newly
// created entities can sometimes be cumbersome. It can then be
// advantageous to use the return value of the transformation commands
// directly. For example, the Translate command returns a list
// containing the ids of the translated entities. For example, we can
// translate copies of the two surfaces 6 and 11 to the right with the
// following command:

my_new_surfs[] = Translate {0.12, 0, 0} { Duplicata{ Surface{6, 11}; } };

// my_new_surfs[] (note the square brackets) denotes a list, which in
// this case contains the ids of the two new surfaces (check
// `Tools->Message console' to see the message):

Printf("New surfaces '%g' and '%g'", my_new_surfs[0], my_new_surfs[1]);

// In Gmsh lists use square brackets for their definition (mylist[] =
// {1,2,3};) as well as to access their elements (myotherlist[] =
// {mylist[0], mylist[2]};). Note that list indexing starts at 0.

// Volumes are the fourth type of elementary entities in Gmsh. In the
// same way one defines line loops to build surfaces, one has to
// define surface loops (i.e. `shells') to build volumes. The
// following volume does not have holes and thus consists of a single
// surface loop:

Point(100) = {0., 0.3, 0.13, lc};  Point(101) = {0.08, 0.3, 0.1, lc};
Point(102) = {0.08, 0.4, 0.1, lc}; Point(103) = {0., 0.4, 0.13, lc};

Line(110) = {4, 100};   Line(111) = {3, 101};
Line(112) = {6, 102};   Line(113) = {5, 103};
Line(114) = {103, 100}; Line(115) = {100, 101};
Line(116) = {101, 102}; Line(117) = {102, 103};

Line Loop(118) = {115, -111, 3, 110};  Plane Surface(119) = {118};
Line Loop(120) = {111, 116, -112, -7}; Plane Surface(121) = {120};
Line Loop(122) = {112, 117, -113, -8}; Plane Surface(123) = {122};
Line Loop(124) = {114, -110, 5, 113};  Plane Surface(125) = {124};
Line Loop(126) = {115, 116, 117, 114}; Plane Surface(127) = {126};

Surface Loop(128) = {127, 119, 121, 123, 125, 11};
Volume(129) = {128};

// When a volume can be extruded from a surface, it is usually easier
// to use the Extrude command directly instead of creating all the
// points, lines and surfaces by hand. For example, the following
// command extrudes the surface 11 along the z axis and automatically
// creates a new volume (as well as all the needed points, lines and
// surfaces):

Extrude {0, 0, 0.12} { Surface{my_new_surfs[1]}; }

// The following command permits to manually assign a characteristic
// length to some of the new points:

Characteristic Length {103, 105, 109, 102, 28, 24, 6, 5} = lc * 3;

// Note that, if the transformation tools are handy to create complex
// geometries, it is also sometimes useful to generate the `flat'
// geometry, with an explicit list of all elementary entities. This
// can be achieved by selecting the `File->Save as->Gmsh unrolled
// geometry' menu or by typing
//
// > gmsh t2.geo -0
//
// on the command line.

// To save all the tetrahedra discretizing the volumes 129 and 130
// with a common region number, we finally define a physical
// volume:

Physical Volume (1) = {129,130};


Next: , Previous: t2.geo, Up: Tutorial

A.3 t3.geo

/*********************************************************************
 *
 *  Gmsh tutorial 3
 *
 *  Extruded meshes, parameters, options
 *
 *********************************************************************/

// Again, we start by including the first tutorial:

Include "t1.geo";

// As in `t2.geo', we plan to perform an extrusion along the z axis.
// But here, instead of only extruding the geometry, we also want to
// extrude the 2D mesh. This is done with the same `Extrude' command,
// but by specifying element 'Layers' (2 layers in this case, the
// first one with 8 subdivisions and the second one with 2
// subdivisions, both with a height of h/2):

h = 0.1;

Extrude {0,0,h} {
  Surface{6}; Layers{ {8,2}, {0.5,1} };
}

// The extrusion can also be performed with a rotation instead of a
// translation, and the resulting mesh can be recombined into prisms
// (we use only one layer here, with 7 subdivisions). All rotations
// are specified by an axis direction ({0,1,0}), an axis point
// ({-0.1,0,0.1}) and a rotation angle (-Pi/2):

Extrude { {0,1,0} , {-0.1,0,0.1} , -Pi/2 } {
  Surface{122}; Layers{7}; Recombine;
}

// Note that a translation ({-2*h,0,0}) and a rotation ({1,0,0},
// {0,0.15,0.25}, Pi/2) can also be combined. Here the angle is
// specified as a 'parameter', using the 'DefineConstant' syntax.
// This parameter can be modified insteractively in the GUI, and
// can be exchanged with other codes using the ONELAB framework:

DefineConstant[ angle = {90, Min 0, Max 120, Step 1,
                         Name "Parameters/Twisting angle"} ];

out[] = Extrude { {-2*h,0,0}, {1,0,0} , {0,0.15,0.25} , angle * Pi / 180 } {
  Surface{144}; Layers{10}; Recombine;
};

// In this last extrusion command we retrieved the volume number
// programatically by using the return value (a list) of the Extrude
// command. This list contains the "top" of the extruded surface (in
// out[0]), the newly created volume (in out[1]) and the ids of the
// lateral surfaces (in out[2], out[3], ...)

// We can then define a new physical volume to save all the tetrahedra
// with a common region number (101):

Physical Volume(101) = {1, 2, out[1]};

// Let us now change some options... Since all interactive options are
// accessible in Gmsh's scripting language, we can for example define
// a global characteristic length factor or redefine some colors
// directly in the input file:

Mesh.CharacteristicLengthFactor = 4;
General.Color.Text = White;
Geometry.Color.Points = Orange;
Mesh.Color.Points = {255,0,0};

// Note that all colors can be defined literally or numerically, i.e.
// `Mesh.Color.Points = Red' is equivalent to `Mesh.Color.Points =
// {255,0,0}'; and also note that, as with user-defined variables, the
// options can be used either as right or left hand sides, so that the
// following command will set the surface color to the same color as
// the points:

Geometry.Color.Surfaces = Geometry.Color.Points;

// You can use the `Help->Current options' menu to see the current
// values of all options. To save all the options in a file, use
// `File->Save as->Gmsh options'. To associate the current options
// with the current file use `File->Save Options->For Current
// File'. To save the current options for all future Gmsh sessions use
// `File->Save Options->As default'.


Next: , Previous: t3.geo, Up: Tutorial

A.4 t4.geo

/********************************************************************* 
 *
 *  Gmsh tutorial 4
 * 
 *  Built-in functions, holes, strings, mesh color
 *
 *********************************************************************/

// As usual, we start by defining some variables:

cm = 1e-02;
e1 = 4.5 * cm; e2 = 6 * cm / 2; e3 =  5 * cm / 2;
h1 = 5 * cm; h2 = 10 * cm; h3 = 5 * cm; h4 = 2 * cm; h5 = 4.5 * cm;
R1 = 1 * cm; R2 = 1.5 * cm; r = 1 * cm;
Lc1 = 0.01;
Lc2 = 0.003;

// We can use all the usual mathematical functions (note the
// capitalized first letters), plus some useful functions like
// Hypot(a, b) := Sqrt(a^2 + b^2):

ccos = (-h5*R1 + e2 * Hypot(h5, Hypot(e2, R1))) / (h5^2 + e2^2);
ssin = Sqrt(1 - ccos^2);

// Then we define some points and some lines using these variables:

Point(1) = {-e1-e2, 0    , 0, Lc1}; Point(2) = {-e1-e2, h1   , 0, Lc1};
Point(3) = {-e3-r , h1   , 0, Lc2}; Point(4) = {-e3-r , h1+r , 0, Lc2};
Point(5) = {-e3   , h1+r , 0, Lc2}; Point(6) = {-e3   , h1+h2, 0, Lc1};
Point(7) = { e3   , h1+h2, 0, Lc1}; Point(8) = { e3   , h1+r , 0, Lc2};
Point(9) = { e3+r , h1+r , 0, Lc2}; Point(10)= { e3+r , h1   , 0, Lc2};
Point(11)= { e1+e2, h1   , 0, Lc1}; Point(12)= { e1+e2, 0    , 0, Lc1};
Point(13)= { e2   , 0    , 0, Lc1};

Point(14)= { R1 / ssin, h5+R1*ccos, 0, Lc2};
Point(15)= { 0        , h5        , 0, Lc2};
Point(16)= {-R1 / ssin, h5+R1*ccos, 0, Lc2};
Point(17)= {-e2       , 0.0       , 0, Lc1};

Point(18)= {-R2 , h1+h3   , 0, Lc2}; Point(19)= {-R2 , h1+h3+h4, 0, Lc2};
Point(20)= { 0  , h1+h3+h4, 0, Lc2}; Point(21)= { R2 , h1+h3+h4, 0, Lc2};
Point(22)= { R2 , h1+h3   , 0, Lc2}; Point(23)= { 0  , h1+h3   , 0, Lc2};

Point(24)= { 0, h1+h3+h4+R2, 0, Lc2}; Point(25)= { 0, h1+h3-R2,    0, Lc2};

Line(1)  = {1 , 17}; 
Line(2)  = {17, 16};

// Gmsh provides other curve primitives than stright lines: splines,
// B-splines, circle arcs, ellipse arcs, etc. Here we define a new
// circle arc, starting at point 14 and ending at point 16, with the
// circle's center being the point 15:

Circle(3) = {14,15,16};
 
// Note that, in Gmsh, circle arcs should always be smaller than
// Pi. We can then define additional lines and circles, as well as a
// new surface:

Line(4)  = {14,13}; Line(5)   = {13,12};  Line(6)  = {12,11}; 
Line(7)  = {11,10}; Circle(8) = {8,9,10}; Line(9)  = {8,7};
Line(10) = {7,6};   Line(11)  = {6,5};    Circle(12) = {3,4,5};
Line(13) = {3,2};   Line(14)  = {2,1};    Line(15) = {18,19};
Circle(16) = {21,20,24}; Circle(17) = {24,20,19};
Circle(18) = {18,23,25}; Circle(19) = {25,23,22}; 
Line(20) = {21,22};

Line Loop(21) = {17,-15,18,19,-20,16};
Plane Surface(22) = {21};

// But we still need to define the exterior surface. Since this
// surface has a hole, its definition now requires two lines loops:

Line Loop(23) = {11,-12,13,14,1,2,-3,4,5,6,7,-8,9,10};
Plane Surface(24) = {23,21};

// As a general rule, if a surface has N holes, it is defined by N+1
// line loops: the first loop defines the exterior boundary; the other
// loops define the boundaries of the holes.

// Finally, we can add some comments by embedding a post-processing
// view containing some strings, and change the color of some mesh
// entities:

View "comments" {
  // Add a text string in window coordinates, 10 pixels from the left
  // and 10 pixels from the bottom:
  T2(10, -10, 0){ "Copyright (C) My Company" };

  // Add another text string in window coordinates, 10 pixels from the
  // left and 15 pixels from the top, using the StrCat() function to
  // concatenate a string with the current date:
  T2(10, 15, 0){ StrCat("File created on ", Today) };

  // Add a text string in model coordinates at (X,Y,Z) = (0, 0.11, 0):
  T3(0, 0.11, 0, 0){ "Hole" };
};

Color Grey50{ Surface{ 22 }; }
Color Purple{ Surface{ 24 }; }
Color Red{ Line{ 1:14 }; }
Color Yellow{ Line{ 15:20 }; }


Next: , Previous: t4.geo, Up: Tutorial

A.5 t5.geo

/*********************************************************************
 *
 *  Gmsh tutorial 5
 *
 *  Characteristic lengths, arrays of variables, functions, loops
 *
 *********************************************************************/

// We start by defining some target mesh sizes:

lcar1 = .1;
lcar2 = .0005;
lcar3 = .055;

// If we wanted to change these mesh sizes globally (without changing
// the above definitions), we could give a global scaling factor for
// all characteristic lengths on the command line with the `-clscale'
// option (or with `Mesh.CharacteristicLengthFactor' in an option
// file). For example, with:
//
// > gmsh t5.geo -clscale 1
//
// this input file produces a mesh of approximately 1,300 nodes and
// 11,000 tetrahedra. With
//
// > gmsh t5.geo -clscale 0.2
//
// the mesh counts approximately 350,000 nodes and 2.1 million
// tetrahedra. You can check mesh statistics in the graphical user
// interface with the `Tools->Statistics' menu.

// We proceed by defining some elementary entities describing a
// truncated cube:

Point(1) = {0.5,0.5,0.5,lcar2}; Point(2) = {0.5,0.5,0,lcar1};
Point(3) = {0,0.5,0.5,lcar1};   Point(4) = {0,0,0.5,lcar1};
Point(5) = {0.5,0,0.5,lcar1};   Point(6) = {0.5,0,0,lcar1};
Point(7) = {0,0.5,0,lcar1};     Point(8) = {0,1,0,lcar1};
Point(9) = {1,1,0,lcar1};       Point(10) = {0,0,1,lcar1};
Point(11) = {0,1,1,lcar1};      Point(12) = {1,1,1,lcar1};
Point(13) = {1,0,1,lcar1};      Point(14) = {1,0,0,lcar1};

Line(1) = {8,9};    Line(2) = {9,12};  Line(3) = {12,11};
Line(4) = {11,8};   Line(5) = {9,14};  Line(6) = {14,13};
Line(7) = {13,12};  Line(8) = {11,10}; Line(9) = {10,13};
Line(10) = {10,4};  Line(11) = {4,5};  Line(12) = {5,6};
Line(13) = {6,2};   Line(14) = {2,1};  Line(15) = {1,3};
Line(16) = {3,7};   Line(17) = {7,2};  Line(18) = {3,4};
Line(19) = {5,1};   Line(20) = {7,8};  Line(21) = {6,14};

Line Loop(22) = {-11,-19,-15,-18};   Plane Surface(23) = {22};
Line Loop(24) = {16,17,14,15};       Plane Surface(25) = {24};
Line Loop(26) = {-17,20,1,5,-21,13}; Plane Surface(27) = {26};
Line Loop(28) = {-4,-1,-2,-3};       Plane Surface(29) = {28};
Line Loop(30) = {-7,2,-5,-6};        Plane Surface(31) = {30};
Line Loop(32) = {6,-9,10,11,12,21};  Plane Surface(33) = {32};
Line Loop(34) = {7,3,8,9};           Plane Surface(35) = {34};
Line Loop(36) = {-10,18,-16,-20,4,-8}; Plane Surface(37) = {36};
Line Loop(38) = {-14,-13,-12,19};    Plane Surface(39) = {38};

// Instead of using included files, we now use a user-defined function
// in order to carve some holes in the cube:

Function CheeseHole

  // In the following commands we use the reserved variable name
  // `newp', which automatically selects a new point number. This
  // number is chosen as the highest current point number, plus
  // one. (Note that, analogously to `newp', the variables `newc',
  // `news', `newv' and `newreg' select the highest number amongst
  // currently defined curves, surfaces, volumes and `any entities
  // other than points', respectively.)

  p1 = newp; Point(p1) = {x,  y,  z,  lcar3} ;
  p2 = newp; Point(p2) = {x+r,y,  z,  lcar3} ;
  p3 = newp; Point(p3) = {x,  y+r,z,  lcar3} ;
  p4 = newp; Point(p4) = {x,  y,  z+r,lcar3} ;
  p5 = newp; Point(p5) = {x-r,y,  z,  lcar3} ;
  p6 = newp; Point(p6) = {x,  y-r,z,  lcar3} ;
  p7 = newp; Point(p7) = {x,  y,  z-r,lcar3} ;

  c1 = newreg; Circle(c1) = {p2,p1,p7}; c2 = newreg; Circle(c2) = {p7,p1,p5};
  c3 = newreg; Circle(c3) = {p5,p1,p4}; c4 = newreg; Circle(c4) = {p4,p1,p2};
  c5 = newreg; Circle(c5) = {p2,p1,p3}; c6 = newreg; Circle(c6) = {p3,p1,p5};
  c7 = newreg; Circle(c7) = {p5,p1,p6}; c8 = newreg; Circle(c8) = {p6,p1,p2};
  c9 = newreg; Circle(c9) = {p7,p1,p3}; c10 = newreg; Circle(c10) = {p3,p1,p4};
  c11 = newreg; Circle(c11) = {p4,p1,p6}; c12 = newreg; Circle(c12) = {p6,p1,p7};

  // We need non-plane surfaces to define the spherical holes. Here we
  // use ruled surfaces, which can have 3 or 4 sides:

  l1 = newreg; Line Loop(l1) = {c5,c10,c4};   Ruled Surface(newreg) = {l1};
  l2 = newreg; Line Loop(l2) = {c9,-c5,c1};   Ruled Surface(newreg) = {l2};
  l3 = newreg; Line Loop(l3) = {c12,-c8,-c1}; Ruled Surface(newreg) = {l3};
  l4 = newreg; Line Loop(l4) = {c8,-c4,c11};  Ruled Surface(newreg) = {l4};
  l5 = newreg; Line Loop(l5) = {-c10,c6,c3};  Ruled Surface(newreg) = {l5};
  l6 = newreg; Line Loop(l6) = {-c11,-c3,c7}; Ruled Surface(newreg) = {l6};
  l7 = newreg; Line Loop(l7) = {-c2,-c7,-c12};Ruled Surface(newreg) = {l7};
  l8 = newreg; Line Loop(l8) = {-c6,-c9,c2};  Ruled Surface(newreg) = {l8};

  // We then store the surface loops identification numbers in a list
  // for later reference (we will need these to define the final
  // volume):

  theloops[t] = newreg ;

  Surface Loop(theloops[t]) = {l8+1,l5+1,l1+1,l2+1,l3+1,l7+1,l6+1,l4+1};

  thehole = newreg ;
  Volume(thehole) = theloops[t] ;

Return

// We can use a `For' loop to generate five holes in the cube:

x = 0 ; y = 0.75 ; z = 0 ; r = 0.09 ;

For t In {1:5}

  x += 0.166 ;
  z += 0.166 ;

  // We call the `CheeseHole' function:

  Call CheeseHole ;

  // We define a physical volume for each hole:

  Physical Volume (t) = thehole ;

  // We also print some variables on the terminal (note that, since
  // all variables are treated internally as floating point numbers,
  // the format string should only contain valid floating point format
  // specifiers like `%g', `%f', '%e', etc.):

  Printf("Hole %g (center = {%g,%g,%g}, radius = %g) has number %g!",
	 t, x, y, z, r, thehole) ;

EndFor

// We can then define the surface loop for the exterior surface of the
// cube:

theloops[0] = newreg ;

Surface Loop(theloops[0]) = {35,31,29,37,33,23,39,25,27} ;

// The volume of the cube, without the 5 holes, is now defined by 6
// surface loops: the first surface loop defines the exterior surface;
// the surface loops other than the first one define holes.  (Again,
// to reference an array of variables, its identifier is followed by
// square brackets):

Volume(186) = {theloops[]} ;

// We finally define a physical volume for the elements discretizing
// the cube, without the holes (whose elements were already tagged
// with numbers 1 to 5 in the `For' loop):

Physical Volume (10) = 186 ;


Next: , Previous: t5.geo, Up: Tutorial

A.6 t6.geo

/********************************************************************* 
 *
 *  Gmsh tutorial 6
 * 
 *  Transfinite meshes
 *
 *********************************************************************/

// Let's use the geometry from the first tutorial as a basis for this
// one
Include "t1.geo";

// Delete the left line and create replace it with 3 new ones
Delete{ Surface{6}; Line{4}; }

p1 = newp; Point(p1) = {-0.05, 0.05, 0, lc};
p2 = newp; Point(p2) = {-0.05, 0.1, 0, lc};

l1 = newl; Line(l1) = {1, p1};
l2 = newl; Line(l2) = {p1, p2};
l3 = newl; Line(l3) = {p2, 4};

// Create surface
Line Loop(1) = {2, -1, l1, l2, l3, -3};
Plane Surface(1) = {1};

// Put 20 points with a refinement toward the extremities on curve 2
Transfinite Line{2} = 20 Using Bump 0.05;

// Put 20 points total on combination of curves l1, l2 and l3 (beware
// that the points p1 and p2 are shared by the curves, so we do not
// create 6 + 6 + 10 = 22 points, but 20!)
Transfinite Line{l1} = 6;
Transfinite Line{l2} = 6;
Transfinite Line{l3} = 10;

// Put 30 points following a geometric progression on curve 1
// (reversed) and on curve 3
Transfinite Line{-1,3} = 30 Using Progression 1.2;

// Define the Surface as transfinite, by specifying the four corners
// of the transfinite interpolation
Transfinite Surface{1} = {1,2,3,4};

// (Note that the list on the right hand side refers to points, not
// curves. When the surface has only 3 or 4 points on its boundary the
// list can be omitted. The way triangles are generated can be
// controlled by appending "Left", "Right" or "Alternate" after the
// list.)

// Recombine the triangles into quads
Recombine Surface{1};

// Apply an elliptic smoother to the grid
Mesh.Smoothing = 100;

Physical Surface(1) = 1;


Next: , Previous: t6.geo, Up: Tutorial

A.7 t7.geo

/********************************************************************* 
 *
 *  Gmsh tutorial 7
 * 
 *  Background mesh
 *
 *********************************************************************/

// Characteristic lengths can be specified very accuractely by
// providing a background mesh, i.e., a post-processing view that
// contains the target mesh sizes.

// Merge the first tutorial
Merge "t1.geo";

// Merge a post-processing view containing the target mesh sizes
Merge "bgmesh.pos";

// Apply the view as the current background mesh
Background Mesh View[0];


Next: , Previous: t7.geo, Up: Tutorial

A.8 t8.geo

/*********************************************************************
 *
 *  Gmsh tutorial 8
 *
 *  Post-processing, scripting, animations, options
 *
 *********************************************************************/

// We first include `t1.geo' as well as some post-processing views:

Include "t1.geo";
Include "view1.pos";
Include "view1.pos";
Include "view4.pos";

// We then set some general options:

General.Trackball = 0;
General.RotationX = 0; General.RotationY = 0; General.RotationZ = 0;
General.Color.Background = White; General.Color.Foreground = Black;
General.Color.Text = Black;
General.Orthographic = 0;
General.Axes = 0; General.SmallAxes = 0;

// We also set some options for each post-processing view:

v0 = PostProcessing.NbViews-4;
v1 = v0+1; v2 = v0+2; v3 = v0+3;

View[v0].IntervalsType = 2;
View[v0].OffsetZ = 0.05;
View[v0].RaiseZ = 0;
View[v0].Light = 1;
View[v0].ShowScale = 0;
View[v0].SmoothNormals = 1;

View[v1].IntervalsType = 1;
View[v1].ColorTable = { Green, Blue };
View[v1].NbIso = 10;
View[v1].ShowScale = 0;

View[v2].Name = "Test...";
View[v2].Axes = 1;
View[v2].Color.Axes = Black;
View[v2].IntervalsType = 2;
View[v2].Type = 2;
View[v2].IntervalsType = 2;
View[v2].AutoPosition = 0;
View[v2].PositionX = 85;
View[v2].PositionY = 50;
View[v2].Width = 200;
View[v2].Height = 130;

View[v3].Visible = 0;

// We then loop from 1 to 3 with a step of 1. (To use a different
// step, just add a third argument in the list. For example, `For num
// In {0.5:1.5:0.1}' would increment num from 0.5 to 1.5 with a step
// of 0.1.)

t = 0;

For num In {1:3}

  View[v0].TimeStep = t;
  View[v1].TimeStep = t;
  View[v2].TimeStep = t;
  View[v3].TimeStep = t;

  t = (View[v0].TimeStep < View[v0].NbTimeStep-1) ? t+1 : 0;

  View[v0].RaiseZ += 0.01/View[v0].Max * t;

  If (num == 3)
    // We want to create 640x480 frames when num == 3:
    General.GraphicsWidth = General.MenuWidth + 640;
    General.GraphicsHeight = 480;
  EndIf

  frames = 50;

  // It is possible to nest loops:
  For num2 In {1:frames}

    General.RotationX += 10;
    General.RotationY = General.RotationX / 3;
    General.RotationZ += 0.1;

    Sleep 0.01; // sleep for 0.01 second
    Draw; // draw the scene (one could use DrawForceChanged instead to force the
          // reconstruction of the vertex arrays, e.g. if changing element
          // clipping)

    If (num == 3)
      // The `Print' command saves the graphical window; the `Sprintf'
      // function permits to create the file names on the fly:
      /*
      Print Sprintf("t8-%02g.gif", num2);
      Print Sprintf("t8-%02g.ppm", num2);
      Print Sprintf("t8-%02g.jpg", num2);
      */
    EndIf

  EndFor

  If(num == 3)
    // Here we could make a system call to generate a movie. For example,

    // with whirlgif:
    /*
    System "whirlgif -minimize -loop -o t8.gif t8-*.gif";
    */

    // with mpeg_encode (create parameter file first, then run encoder):
    /*
    Printf("PATTERN I") > "t8.par";
    Printf("BASE_FILE_FORMAT PPM") >> "t8.par";
    Printf("GOP_SIZE 1") >> "t8.par";
    Printf("SLICES_PER_FRAME 1") >> "t8.par";
    Printf("PIXEL HALF") >> "t8.par";
    Printf("RANGE 10") >> "t8.par";
    Printf("PSEARCH_ALG EXHAUSTIVE") >> "t8.par";
    Printf("BSEARCH_ALG CROSS2") >> "t8.par";
    Printf("IQSCALE 1") >> "t8.par";
    Printf("PQSCALE 1") >> "t8.par";
    Printf("BQSCALE 25") >> "t8.par";
    Printf("REFERENCE_FRAME DECODED") >> "t8.par";
    Printf("OUTPUT t8.mpg") >> "t8.par";
    Printf("INPUT_CONVERT *") >> "t8.par";
    Printf("INPUT_DIR .") >> "t8.par";
    Printf("INPUT") >> "t8.par";
    tmp = Sprintf("t8-*.ppm [01-%02g]", frames);
    Printf(tmp) >> "t8.par";
    Printf("END_INPUT") >> "t8.par";
    System "mpeg_encode t8.par";
    */

    // with mencoder:
    /*
    System "mencoder 'mf://*.jpg' -mf fps=5 -o t8.mpg -ovc lavc
            -lavcopts vcodec=mpeg1video:vhq";
    System "mencoder 'mf://*.jpg' -mf fps=5 -o t8.mpg -ovc lavc
           -lavcopts vcodec=mpeg4:vhq";
    */

    // with ffmpeg:
    /*
    System "ffmpeg -hq -r 5 -b 800 -vcodec mpeg1video
            -i t8-%02d.jpg t8.mpg"
    System "ffmpeg -hq -r 5 -b 800 -i t8-%02d.jpg t8.asf"
    */
  EndIf

EndFor


Next: , Previous: t8.geo, Up: Tutorial

A.9 t9.geo

/********************************************************************* 
 *
 *  Gmsh tutorial 9
 * 
 *  Post-processing plugins (levelsets, sections, annotations)
 *
 *********************************************************************/

// Plugins can be added to Gmsh in order to extend its
// capabilities. For example, post-processing plugins can modify a
// view, or create a new view based on previously loaded
// views. Several default plugins are statically linked with Gmsh,
// e.g. Isosurface, CutPlane, CutSphere, Skin, Transform or Smooth.
// Plugins can be controlled in the same way as other options: either
// from the graphical interface (right click on the view button, then
// `Plugins'), or from the command file.

// Let us for example include a three-dimensional scalar view:

Include "view3.pos" ;

// We then set some options for the `Isosurface' plugin (which
// extracts an isosurface from a 3D scalar view), and run it:

Plugin(Isosurface).Value = 0.67 ; // iso-value level
Plugin(Isosurface).View = 0 ; // source view is View[0]
Plugin(Isosurface).Run ; // run the plugin!

// We also set some options for the `CutPlane' plugin (which computes
// a section of a 3D view using the plane A*x+B*y+C*z+D=0), and then
// run it:

Plugin(CutPlane).A = 0 ; 
Plugin(CutPlane).B = 0.2 ; 
Plugin(CutPlane).C = 1 ; 
Plugin(CutPlane).D = 0 ; 
Plugin(CutPlane).View = 0 ;
Plugin(CutPlane).Run ; 

// Add a title (By convention, for window coordinates a value greater
// than 99999 represents the center. We could also use
// `General.GraphicsWidth / 2', but that would only center the string
// for the current window size.):

Plugin(Annotate).Text = "A nice title" ; 
Plugin(Annotate).X = 1.e5;
Plugin(Annotate).Y = 50 ; 
Plugin(Annotate).Font = "Times-BoldItalic" ; 
Plugin(Annotate).FontSize = 28 ; 
Plugin(Annotate).Align = "Center" ; 
Plugin(Annotate).View = 0 ;
Plugin(Annotate).Run ; 

Plugin(Annotate).Text = "(and a small subtitle)" ; 
Plugin(Annotate).Y = 70 ; 
Plugin(Annotate).Font = "Times-Roman" ; 
Plugin(Annotate).FontSize = 12 ; 
Plugin(Annotate).Run ; 

// We finish by setting some options:

View[0].Light = 1;
View[0].IntervalsType = 1;
View[0].NbIso = 6;
View[0].SmoothNormals = 1;
View[1].IntervalsType = 2;
View[2].IntervalsType = 2;


Next: , Previous: t9.geo, Up: Tutorial

A.10 t10.geo

/********************************************************************* 
 *
 *  Gmsh tutorial 10
 * 
 *  General mesh size fields
 *
 *********************************************************************/

// In addition to specifying target mesh sizes at the points of the
// geometry (see t1) or using a background mesh (see t7), you can use
// general mesh size "Fields". 

// Let's create a simple rectangular geometry
lc = .15;
Point(1) = {0.0,0.0,0,lc}; Point(2) = {1,0.0,0,lc}; 
Point(3) = {1,1,0,lc};     Point(4) = {0,1,0,lc}; 
Point(5) = {0.2,.5,0,lc};

Line(1) = {3,2}; Line(2) = {2,1}; Line(3) = {1,4}; Line(4) = {4,3};

Line Loop(5) = {1,2,3,4}; Plane Surface(6) = {5};

// Say we would like to obtain mesh elements with size lc/30 near line
// 1 and point 5, and size lc elsewhere. To achieve this, we can use
// two fields: "Attractor", and "Threshold". We first define an
// Attractor field (Field[1]) on points 5 and on line 1. This field
// returns the distance to point 5 and to (100 equidistant points on)
// line 1.
Field[1] = Attractor;
Field[1].NodesList = {5};
Field[1].NNodesByEdge = 100;
Field[1].EdgesList = {1};

// We then define a Threshold field, which uses the return value of
// the Attractor Field[1] in order to define a simple change in
// element size around the attractors (i.e., around point 5 and line
// 1)
//
// LcMax -                         /------------------
//                               /
//                             /
//                           /
// LcMin -o----------------/
//        |                |       |
//     Attractor       DistMin   DistMax
Field[2] = Threshold;
Field[2].IField = 1;
Field[2].LcMin = lc / 30;
Field[2].LcMax = lc;
Field[2].DistMin = 0.15;
Field[2].DistMax = 0.5;

// Say we want to modulate the mesh element sizes using a mathematical
// function of the spatial coordinates. We can do this with the
// MathEval field:
Field[3] = MathEval;
Field[3].F = "Cos(4*3.14*x) * Sin(4*3.14*y) / 10 + 0.101";

// We could also combine MathEval with values coming from other
// fields. For example, let's define an Attractor around point 1
Field[4] = Attractor;
Field[4].NodesList = {1};

// We can then create a MathEval field with a function that depends on
// the return value of the Attractr Field[4], i.e., depending on the
// distance to point 1 (here using a cubic law, with minumum element
// size = lc / 100)
Field[5] = MathEval;
Field[5].F = Sprintf("F4^3 + %g", lc / 100);

// We could also use a Box field to impose a step change in element
// sizes inside a box
Field[6] = Box;
Field[6].VIn = lc / 15;
Field[6].VOut = lc;
Field[6].XMin = 0.3; 
Field[6].XMax = 0.6;
Field[6].YMin = 0.3;
Field[6].YMax = 0.6;

// Many other types of fields are available: see the reference manual
// for a complete list. You can also create fields directly in the
// graphical user interface by selecting Define->Fields in the Mesh
// module.

// Finally, let's use the minimum of all the fields as the background
// mesh field
Field[7] = Min;
Field[7].FieldsList = {2, 3, 5, 6};
Background Field = 7;

// Don't extend the elements sizes from the boundary inside the domain
Mesh.CharacteristicLengthExtendFromBoundary = 0;


Next: , Previous: t10.geo, Up: Tutorial

A.11 t11.geo

/********************************************************************* 
 *
 *  Gmsh tutorial 11
 * 
 *  Unstructured quadrangular meshes
 *
 *********************************************************************/

// We have seen in tutorials t3 and t6 that extruded and transfinite
// meshes can be "recombined" into quads/prisms/hexahedra by using the
// "Recombine" keyword. Unstructured meshes can be recombined in the
// same way. Let's define a simple geometry with an analytical mesh
// size field:

Point(1) = {-1.25, -.5, 0}; Point(2) = {-1.25, 1.25, 0};
Point(3) = {1.25, -.5, 0};  Point(4) = {1.25, 1.25, 0};

Line(1) = {1, 2}; Line(2) = {2, 4};
Line(3) = {4, 3}; Line(4) = {3, 1};

Line Loop(4) = {1,2, 3, 4}; Plane Surface(100) = {4};

Field[1] = MathEval;
Field[1].F = "0.01*(1.0+30.*(y-x*x)*(y-x*x) + (1-x)*(1-x))";
Background Field = 1;

// To generate quadrangles instead of triangles, we can simply add
Recombine Surface{100};

// If we'd had several surfaces, we could have used 'Recombine Surface
// "*";'. Yet another way would be to specify the global option
// "Mesh.RecombineAll = 1;".

// The default recombination algorithm is called "Blossom": it uses a
// minimum cost perfect matching algorithm to generate fully
// quadrilateral meshes from triangulations. More details about the
// algorithm can be found in the following paper: J.-F. Remacle,
// J. Lambrechts, B. Seny, E. Marchandise, A. Johnen and C. Geuzaine,
// "Blossom-Quad: a non-uniform quadrilateral mesh generator using a
// minimum cost perfect matching algorithm", International Journal for
// Numerical Methods in Engineering, 2011 (in press).

// For even better quadrilateral meshes, you can try the experimental
// "Delaunay for quads" (DelQuad) meshing algorithm: DelQuad is a
// triangulation algorithm that enables to create right triangles
// almost everywhere. Uncomment the following line to try DelQuad:

Mesh.Algorithm = 8; // DelQuad (experimental)


Next: , Previous: t11.geo, Up: Tutorial

A.12 t12.geo

/********************************************************************* 
 *
 *  Gmsh tutorial 12
 * 
 *  Cross-patch meshing with compounds
 *
 *********************************************************************/

// Compound geometrical entities can be defined to compute a new
// parametrization of groups of elementary geometrical entities. This
// parametrization can then be used for remeshing the compound as if
// it were a single CAD entity.

lc = 0.2;

Point(1) = {0, 0, 0, lc};       Point(2) = {1, 0, 0, lc};
Point(3) = {1, 1, 0.5, lc};     Point(4) = {0, 1, 0.4, lc};
Point(5) = {0.3, 0.2, 0, lc};   Point(6) = {0, 0.01, 0.01, lc};
Point(7) = {0, 0.02, 0.02, lc}; Point(8) = {1, 0.05, 0.02, lc};
Point(9) = {1, 0.32, 0.02, lc};

Line(1) = {1, 2}; Line(2) = {2, 8}; Line(3) = {8, 9}; 
Line(4) = {9, 3}; Line(5) = {3, 4}; Line(6) = {4, 7}; 
Line(7) = {7, 6}; Line(8) = {6, 1}; Spline(9) = {7, 5, 9}; 
Line(10) = {6, 8};

Line Loop(11) = {5, 6, 9, 4};     Ruled Surface(12) = {11};
Line Loop(13) = {9, -3, -10, -7}; Ruled Surface(14) = {13};
Line Loop(15) = {10, -2, -1, -8}; Ruled Surface(16) = {15};

// Treat lines 2, 3 and 4 as a single line
Compound Line(100) = {2, 3, 4};
// Idem with lines 6, 7 and 8
Compound Line(101) = {6, 7, 8};

// Treat surfaces 12, 14 and 16 as a single surface
Compound Surface(200) = {12, 14, 16};

// Hide the original surfaces so we only see the compound
// (cross-patch) mesh
//Hide {Surface{12, 14, 16}; }

// More details about the reparametrization technique can be found in
// the following papers:
//
// * J.-F. Remacle, C. Geuzaine, G. Compère and E. Marchandise,
//   "High-Quality Surface Remeshing Using Harmonic Maps",
//   International Journal for Numerical Methods in Engineering,
//   83 (4), pp. 403-425, 2010.
//
// * E. Marchandise, G. Compère, M. Willemet, G. Bricteux, C. Geuzaine
//   and J-F Remacle, "Quality meshing based on STL triangulations for
//   biomedical simulations", International Journal for Numerical
//   Methods in Biomedical Engineering", 26 (7), pp. 876-889, 2010.
// 
// * E. Marchandise, C. Carton de Wiart, W. G. Vos, C. Geuzaine and
//   J.-F. Remacle, "High Quality Surface Remeshing Using Harmonic
//   Maps. Part II: Surfaces with High Genus and of Large Aspect
//   Ratio", International Journal for Numerical Methods in
//   Engineering, 86 (11), pp. 1303-1321, 2011.


Next: , Previous: t12.geo, Up: Tutorial

A.13 t13.geo

/*********************************************************************
 *
 *  Gmsh tutorial 13
 *
 *  Remeshing STL with compounds
 *
 *********************************************************************/

// Since compound geometrical compute a new parametrization, one can
// also use them to remesh STL files, even if in this case there's
// usually only a single elementary geometrical entity per compound.

// Let's merge the mesh that we would like to remesh. This mesh was
// reclassified ("colored") from an initial STL triangulation using
// the "Reclassify 2D" tool in Gmsh, so that we could split it along
// sharp geometrical features.
Merge "t13_data.msh";

// Since the original mesh is a bit coarse, we refine it once
RefineMesh;

// Create the topology of the discrete model
CreateTopology;

// We can now define a compound line (resp. surface) for each discrete
// line (resp. surface) in the model
ll[] = Line "*";
For j In {0 : #ll[]-1}
  Compound Line(newl) = ll[j];
EndFor
ss[] = Surface "*";
s = news;
For i In {0 : #ss[]-1}
  Compound Surface(s+i) = ss[i];
EndFor

// And we can create the volume based on the new compound entities
Surface Loop(1) = {s : s + #ss[]-1};
Volume(1) = {1};

Physical Surface(1) = {s : s + #ss[]-1};
Physical Volume(1) = 1;

uniform = 1;
If(uniform)
  // uniform mesh size...
  Mesh.CharacteristicLengthMin = 2.5;
  Mesh.CharacteristicLengthMax = 2.5;
EndIf
If(!uniform)
  // ... or apply a funny mesh size field, just because we can :-)
  Field[1] = MathEval;
  Field[1].F = "2*Sin((x+y)/5) + 3";
  Background Field = 1;
EndIf

Mesh.RemeshAlgorithm = 1; // (0) no split (1) automatic (2) automatic only with metis
Mesh.RemeshParametrization = 7; // (0) harmonic (1) conformal spectral (7) conformal finite element
Geometry.HideCompounds = 0; // don't hide the compound entities
Mesh.Algorithm = 6; // Frontal


Next: , Previous: t13.geo, Up: Tutorial

A.14 t14.geo

/********************************************************************* 
 *
 *  Gmsh tutorial 14
 *
 *  Homology and cohomology computation
 *
 *********************************************************************/
 
// Homology computation in Gmsh finds representative chains of
// (relative) (co)homology space bases using a mesh of a model. 
// The representative basis chains are stored in the mesh as 
// physical groups of Gmsh, one for each chain. 

// Create an example geometry

m = 0.5; // mesh characteristic length
h = 2; // height in the z-direction

Point(1) = {0, 0, 0, m};   Point(2) = {10, 0, 0, m};
Point(3) = {10, 10, 0, m}; Point(4) = {0, 10, 0, m};
Point(5) = {4, 4, 0, m};   Point(6) = {6, 4, 0, m};
Point(7) = {6, 6, 0, m};   Point(8) = {4, 6, 0, m};

Point(9) = {2, 0, 0, m};   Point(10) = {8, 0, 0, m};
Point(11) = {2, 10, 0, m}; Point(12) = {8, 10, 0, m};

Line(1) = {1, 9};  Line(2) = {9, 10}; Line(3) = {10, 2};
Line(4) = {2, 3};  Line(5) = {3, 12}; Line(6) = {12, 11};
Line(7) = {11, 4}; Line(8) = {4, 1};  Line(9) = {5, 6};
Line(10) = {6, 7}; Line(11) = {7, 8}; Line(12) = {8, 5};

Line Loop(13) = {6, 7, 8, 1, 2, 3, 4, 5};
Line Loop(14) = {11, 12, 9, 10};
Plane Surface(15) = {13, 14};

Extrude {0, 0, h}{ Surface{15}; }

// Create physical groups, which are used to define the domain of the
// (co)homology computation and the subdomain of the relative (co)homology
// computation.

// Whole domain
Physical Volume(1) = {1};

// Four "terminals" of the model
Physical Surface(70) = {36};
Physical Surface(71) = {44};
Physical Surface(72) = {52};
Physical Surface(73) = {60};

// Whole domain surface
bnd[] = Boundary{ Volume{1}; };
Physical Surface(80) = bnd[];

// Complement of the domain surface respect to the four terminals
bnd[] -= {36, 44, 52, 60};
Physical Surface(75) = bnd[];

// Find bases for relative homology spaces of 
// the domain modulo the four terminals.
Homology {{1}, {70, 71, 72, 73}};

// Find homology space bases isomorphic to the previous bases: 
// homology spaces modulo the non-terminal domain surface,
// a.k.a the thin cuts.
Homology {{1}, {75}};

// Find cohomology space bases isomorphic to the previous bases: 
// cohomology spaces of the domain modulo the four terminals,
// a.k.a the thick cuts.
Cohomology {{1}, {70, 71, 72, 73}};

// More examples:
//  Homology {1};
//  Homology;
//  Homology {{1}, {80}};
//  Homology {{}, {80}};


Previous: t14.geo, Up: Tutorial

A.15 t15.geo

/*********************************************************************
 *
 *  Gmsh tutorial 15
 *
 *  Embedded points, lines and surfaces
 *
 *********************************************************************/

// We start one again by including the first tutorial:
Include "t1.geo";

// We define a new point
Point(5) = {0.02, 0.02, 0, lc/10};

// One can force this point to be included ("embedded") in the 2D mesh, using
// the "Point In Surface" command:
Point{5} In Surface{6};

// In the same way, one can force a curve to be embedded in the 2D mesh using
// the "Line in Surface" command:
Point(6) = {0.02, 0.12, 0, lc/5};
Point(7) = {0.04, 0.18, 0, lc/5};
Line(5) = {6, 7};

Line{5} In Surface{6};

// Finally, one can also embed a surface in a volume using the "Surface In
// Volume" command:
Extrude {0, 0, 0.1}{ Surface {6}; }

p = newp;
Point(p) = {0.02, 0.12, 0.05, lc/5};
Point(p+1) = {0.04, 0.12, 0.05, lc/5};
Point(p+2) = {0.04, 0.18, 0.05, lc/5};
Point(p+3) = {0.02, 0.18, 0.05, lc/5};
l = newl;
Line(l) = {p, p+1};
Line(l+1) = {p+1, p+2};
Line(l+2) = {p+2, p+3};
Line(l+3) = {p+3, p};
ll = newll;
Line Loop(ll) = {l:l+3};
s = news;
Plane Surface(s) = {ll};

Surface{s} In Volume{1};


Next: , Previous: Tutorial, Up: Top

Appendix B Options

This appendix lists all the available options. Gmsh's default behavior is to save some of these options in a per-user “session resource” file (cf. “Saved in: General.SessionFileName” in the lists below) every time Gmsh is shut down. This permits for example to automatically remember the size and location of the windows or which fonts to use. A second set of options can be saved (automatically or manually with the `File->Save Options->As Default' menu) in a per-user “option” file (cf. “Saved in: General.OptionsFileName” in the lists below), automatically loaded by Gmsh every time it starts up. Finally, other options are only saved to disk manually, either by explicitely saving an option file with `File->Save As', or when saving per-model options with `File->Save Options->For Current File' (cf. “Saved in: -” in the lists below).

To reset all options to their default values, use the `Restore default options' button in `Tools->Options->General->Advanced', or erase the General.SessionFileName and General.OptionsFileName files by hand.


Next: , Previous: Options, Up: Options

B.1 General options list

General.AxesFormatX
Number format for X-axis (in standard C form)
Default value: "%.3g"
Saved in: General.OptionsFileName
General.AxesFormatY
Number format for Y-axis (in standard C form)
Default value: "%.3g"
Saved in: General.OptionsFileName
General.AxesFormatZ
Number format for Z-axis (in standard C form)
Default value: "%.3g"
Saved in: General.OptionsFileName
General.AxesLabelX
X-axis label
Default value: ""
Saved in: General.OptionsFileName
General.AxesLabelY
Y-axis label
Default value: ""
Saved in: General.OptionsFileName
General.AxesLabelZ
Z-axis label
Default value: ""
Saved in: General.OptionsFileName
General.BackgroundImageFileName
Background image file in JPEG or PNG format
Default value: ""
Saved in: General.OptionsFileName
General.DefaultFileName
Default project file name
Default value: "untitled.geo"
Saved in: General.OptionsFileName
General.Display
X server to use (only for Unix versions)
Default value: ""
Saved in: -
General.ErrorFileName
File into which the log is saved if a fatal error occurs
Default value: ".gmsh-errors"
Saved in: General.OptionsFileName
General.FileName
Current project file name (read-only)
Default value: ""
Saved in: -
General.FltkTheme
FLTK user interface theme (try e.g. plastic or gtk+)
Default value: ""
Saved in: General.OptionsFileName
General.GraphicsFont
Font used in the graphic window
Default value: "Helvetica"
Saved in: General.OptionsFileName
General.GraphicsFontEngine
Set graphics font engine (Native, Cairo)
Default value: "Native"
Saved in: General.OptionsFileName
General.GraphicsFontTitle
Font used in the graphic window for titles
Default value: "Helvetica"
Saved in: General.OptionsFileName
General.OptionsFileName
Option file created with `Tools->Options->Save'; automatically read on startup
Default value: ".gmsh-options"
Saved in: General.SessionFileName
General.RecentFile0
Most recent opened file
Default value: "untitled.geo"
Saved in: General.SessionFileName
General.RecentFile1
2nd most recent opened file
Default value: "untitled.geo"
Saved in: General.SessionFileName
General.RecentFile2
3rd most recent opened file
Default value: "untitled.geo"
Saved in: General.SessionFileName
General.RecentFile3
4th most recent opened file
Default value: "untitled.geo"
Saved in: General.SessionFileName
General.RecentFile4
5th most recent opened file
Default value: "untitled.geo"
Saved in: General.SessionFileName
General.SessionFileName
Option file into which session specific information is saved; automatically read on startup
Default value: ".gmshrc"
Saved in: -
General.TextEditor
System command to launch a text editor
Default value: "open -t %s"
Saved in: General.OptionsFileName
General.TmpFileName
Temporary file used by the geometry module
Default value: ".gmsh-tmp"
Saved in: General.SessionFileName
General.WatchFilePattern
Pattern of files to merge as they become available
Default value: ""
Saved in: -
General.AlphaBlending
Enable alpha blending (transparency) in post-processing views
Default value: 1
Saved in: General.OptionsFileName
General.Antialiasing
Use multisample antialiasing (will slow down rendering)
Default value: 0
Saved in: General.OptionsFileName
General.ArrowHeadRadius
Relative radius of arrow head
Default value: 0.12
Saved in: General.OptionsFileName
General.ArrowStemLength
Relative length of arrow stem
Default value: 0.56
Saved in: General.OptionsFileName
General.ArrowStemRadius
Relative radius of arrow stem
Default value: 0.02
Saved in: General.OptionsFileName
General.Axes
Axes (0=none, 1=simple axes, 2=box, 3=full grid, 4=open grid, 5=ruler)
Default value: 0
Saved in: General.OptionsFileName
General.AxesMikado
Mikado axes style
Default value: 0
Saved in: General.OptionsFileName
General.AxesAutoPosition
Position the axes automatically
Default value: 1
Saved in: General.OptionsFileName
General.AxesForceValue
Force values on axes (otherwise use natural coordinates)
Default value: 0
Saved in: General.OptionsFileName
General.AxesMaxX
Maximum X-axis coordinate
Default value: 1
Saved in: General.OptionsFileName
General.AxesMaxY
Maximum Y-axis coordinate
Default value: 1
Saved in: General.OptionsFileName
General.AxesMaxZ
Maximum Z-axis coordinate
Default value: 1
Saved in: General.OptionsFileName
General.AxesMinX
Minimum X-axis coordinate
Default value: 0
Saved in: General.OptionsFileName
General.AxesMinY
Minimum Y-axis coordinate
Default value: 0
Saved in: General.OptionsFileName
General.AxesMinZ
Minimum Z-axis coordinate
Default value: 0
Saved in: General.OptionsFileName
General.AxesTicsX
Number of tics on the X-axis
Default value: 5
Saved in: General.OptionsFileName
General.AxesTicsY
Number of tics on the Y-axis
Default value: 5
Saved in: General.OptionsFileName
General.AxesTicsZ
Number of tics on the Z-axis
Default value: 5
Saved in: General.OptionsFileName
General.AxesValueMaxX
Maximum X-axis forced value
Default value: 1
Saved in: General.OptionsFileName
General.AxesValueMaxY
Maximum Y-axis forced value
Default value: 1
Saved in: General.OptionsFileName
General.AxesValueMaxZ
Maximum Z-axis forced value
Default value: 1
Saved in: General.OptionsFileName
General.AxesValueMinX
Minimum X-axis forced value
Default value: 0
Saved in: General.OptionsFileName
General.AxesValueMinY
Minimum Y-axis forced value
Default value: 0
Saved in: General.OptionsFileName
General.AxesValueMinZ
Minimum Z-axis forced value
Default value: 0
Saved in: General.OptionsFileName
General.BackgroundGradient
Draw background gradient (0=none, 1=vertical, 2=horizontal, 3=radial)
Default value: 1
Saved in: General.OptionsFileName
General.BackgroundImagePositionX
X position (in pixels) of background image (< 0: measure from right edge; >= 1e5: centered)
Default value: 100000
Saved in: General.OptionsFileName
General.BackgroundImagePositionY
Y position (in pixels) of background image (< 0: measure from bottom edge; >= 1e5: centered)
Default value: 100000
Saved in: General.OptionsFileName
General.Camera
Enable camera view mode
Default value: 0
Saved in: General.OptionsFileName
General.CameraAperture
Camera aperture in degrees
Default value: 40
Saved in: General.OptionsFileName
General.CameraEyeSeparationRatio
Eye separation ratio in % for stereo rendering
Default value: 1.5
Saved in: General.OptionsFileName
General.CameraFocalLengthRatio
Camera Focal length ratio
Default value: 1
Saved in: General.OptionsFileName
General.Clip0A
First coefficient in equation for clipping plane 0 (`A' in `AX+BY+CZ+D=0')
Default value: 1
Saved in: -
General.Clip0B
Second coefficient in equation for clipping plane 0 (`B' in `AX+BY+CZ+D=0')
Default value: 0
Saved in: -
General.Clip0C
Third coefficient in equation for clipping plane 0 (`C' in `AX+BY+CZ+D=0')
Default value: 0
Saved in: -
General.Clip0D
Fourth coefficient in equation for clipping plane 0 (`D' in `AX+BY+CZ+D=0')
Default value: 0
Saved in: -
General.Clip1A
First coefficient in equation for clipping plane 1
Default value: 0
Saved in: -
General.Clip1B
Second coefficient in equation for clipping plane 1
Default value: 1
Saved in: -
General.Clip1C
Third coefficient in equation for clipping plane 1
Default value: 0
Saved in: -
General.Clip1D
Fourth coefficient in equation for clipping plane 1
Default value: 0
Saved in: -
General.Clip2A
First coefficient in equation for clipping plane 2
Default value: 0
Saved in: -
General.Clip2B
Second coefficient in equation for clipping plane 2
Default value: 0
Saved in: -
General.Clip2C
Third coefficient in equation for clipping plane 2
Default value: 1
Saved in: -
General.Clip2D
Fourth coefficient in equation for clipping plane 2
Default value: 0
Saved in: -
General.Clip3A
First coefficient in equation for clipping plane 3
Default value: -1
Saved in: -
General.Clip3B
Second coefficient in equation for clipping plane 3
Default value: 0
Saved in: -
General.Clip3C
Third coefficient in equation for clipping plane 3
Default value: 0
Saved in: -
General.Clip3D
Fourth coefficient in equation for clipping plane 3
Default value: 1
Saved in: -
General.Clip4A
First coefficient in equation for clipping plane 4
Default value: 0
Saved in: -
General.Clip4B
Second coefficient in equation for clipping plane 4
Default value: -1
Saved in: -
General.Clip4C
Third coefficient in equation for clipping plane 4
Default value: 0
Saved in: -
General.Clip4D
Fourth coefficient in equation for clipping plane 4
Default value: 1
Saved in: -
General.Clip5A
First coefficient in equation for clipping plane 5
Default value: 0
Saved in: -
General.Clip5B
Second coefficient in equation for clipping plane 5
Default value: 0
Saved in: -
General.Clip5C
Third coefficient in equation for clipping plane 5
Default value: -1
Saved in: -
General.Clip5D
Fourth coefficient in equation for clipping plane 5
Default value: 1
Saved in: -
General.ClipFactor
Near and far clipping plane distance factor (decrease value for better z-buffer resolution)
Default value: 5
Saved in: -
General.ClipOnlyDrawIntersectingVolume
Only draw layer of elements that intersect the clipping plane
Default value: 0
Saved in: General.OptionsFileName
General.ClipOnlyVolume
Only clip volume elements
Default value: 0
Saved in: General.OptionsFileName
General.ClipPositionX
Horizontal position (in pixels) of the upper left corner of the clipping planes window
Default value: 650
Saved in: General.SessionFileName
General.ClipPositionY
Vertical position (in pixels) of the upper left corner of the clipping planes window
Default value: 150
Saved in: General.SessionFileName
General.ClipWholeElements
Clip whole elements
Default value: 0
Saved in: General.OptionsFileName
General.ColorScheme
Default color scheme (0=dark, 1=light or 2=grayscale)
Default value: 1
Saved in: General.OptionsFileName
General.ConfirmOverwrite
Ask confirmation before overwriting files?
Default value: 1
Saved in: General.OptionsFileName
General.ContextPositionX
Horizontal position (in pixels) of the upper left corner of the contextual windows
Default value: 650
Saved in: General.SessionFileName
General.ContextPositionY
Vertical position (in pixels) of the upper left corner of the contextual windows
Default value: 150
Saved in: General.SessionFileName
General.DetachedMenu
Should the menu window be detached from the graphic window?
Default value: 0
Saved in: General.SessionFileName
General.DisplayBorderFactor
Border factor for model display (0: model fits window size exactly)
Default value: 0.2
Saved in: General.OptionsFileName
General.DoubleBuffer
Use a double buffered graphic window (on Unix, should be set to 0 when working on a remote host without GLX)
Default value: 1
Saved in: General.OptionsFileName
General.DrawBoundingBoxes
Draw bounding boxes
Default value: 0
Saved in: General.OptionsFileName
General.ExpertMode
Enable expert mode (to disable all the messages meant for inexperienced users)
Default value: 0
Saved in: General.OptionsFileName
General.ExtraPositionX
Horizontal position (in pixels) of the upper left corner of the generic extra window
Default value: 650
Saved in: General.SessionFileName
General.ExtraPositionY
Vertical position (in pixels) of the upper left corner of the generic extra window
Default value: 350
Saved in: General.SessionFileName
General.ExtraHeight
Height (in pixels) of the generic extra window
Default value: 100
Saved in: General.SessionFileName
General.ExtraWidth
Width (in pixels) of the generic extra window
Default value: 100
Saved in: General.SessionFileName
General.FastRedraw
Draw simplified model while rotating, panning and zooming
Default value: 0
Saved in: General.OptionsFileName
General.FieldPositionX
Horizontal position (in pixels) of the upper left corner of the field window
Default value: 650
Saved in: General.SessionFileName
General.FieldPositionY
Vertical position (in pixels) of the upper left corner of the field window
Default value: 550
Saved in: General.SessionFileName
General.FieldHeight
Height (in pixels) of the field window
Default value: 320
Saved in: General.SessionFileName
General.FieldWidth
Width (in pixels) of the field window
Default value: 420
Saved in: General.SessionFileName
General.FileChooserPositionX
Horizontal position (in pixels) of the upper left corner of the file chooser windows
Default value: 200
Saved in: General.SessionFileName
General.FileChooserPositionY
Vertical position (in pixels) of the upper left corner of the file chooser windows
Default value: 200
Saved in: General.SessionFileName
General.FontSize
Size of the font in the user interface (-1=automatic)
Default value: -1
Saved in: General.OptionsFileName
General.GraphicsFontSize
Size of the font in the graphic window
Default value: 15
Saved in: General.OptionsFileName
General.GraphicsFontSizeTitle
Size of the font in the graphic window for titles
Default value: 18
Saved in: General.OptionsFileName
General.GraphicsHeight
Height (in pixels) of the graphic window
Default value: 600
Saved in: General.SessionFileName
General.GraphicsPositionX
Horizontal position (in pixels) of the upper left corner of the graphic window
Default value: 50
Saved in: General.SessionFileName
General.GraphicsPositionY
Vertical position (in pixels) of the upper left corner of the graphic window
Default value: 50
Saved in: General.SessionFileName
General.GraphicsWidth
Width (in pixels) of the graphic window
Default value: 800
Saved in: General.SessionFileName
General.HighOrderToolsPositionX
Horizontal position (in pixels) of the upper left corner of the high order tools window
Default value: 650
Saved in: General.SessionFileName
General.HighOrderToolsPositionY
Vertical position (in pixels) of the upper left corner of the high order tools window
Default value: 150
Saved in: General.SessionFileName
General.InitialModule
Module launched on startup (0=automatic, 1=geometry, 2=mesh, 3=solver, 4=post-processing)
Default value: 0
Saved in: General.OptionsFileName
General.Light0
Enable light source 0
Default value: 1
Saved in: General.OptionsFileName
General.Light0X
X position of light source 0
Default value: 0.65
Saved in: General.OptionsFileName
General.Light0Y
Y position of light source 0
Default value: 0.65
Saved in: General.OptionsFileName
General.Light0Z
Z position of light source 0
Default value: 1
Saved in: General.OptionsFileName
General.Light0W
Divisor of the X, Y and Z coordinates of light source 0 (W=0 means infinitely far source)
Default value: 0
Saved in: General.OptionsFileName
General.Light1
Enable light source 1
Default value: 0
Saved in: General.OptionsFileName
General.Light1X
X position of light source 1
Default value: 0.5
Saved in: General.OptionsFileName
General.Light1Y
Y position of light source 1
Default value: 0.3
Saved in: General.OptionsFileName
General.Light1Z
Z position of light source 1
Default value: 1
Saved in: General.OptionsFileName
General.Light1W
Divisor of the X, Y and Z coordinates of light source 1 (W=0 means infinitely far source)
Default value: 0
Saved in: General.OptionsFileName
General.Light2
Enable light source 2
Default value: 0
Saved in: General.OptionsFileName
General.Light2X
X position of light source 2
Default value: 0.5
Saved in: General.OptionsFileName
General.Light2Y
Y position of light source 2
Default value: 0.3
Saved in: General.OptionsFileName
General.Light2Z
Z position of light source 2
Default value: 1
Saved in: General.OptionsFileName
General.Light2W
Divisor of the X, Y and Z coordinates of light source 2 (W=0 means infinitely far source)
Default value: 0
Saved in: General.OptionsFileName
General.Light3
Enable light source 3
Default value: 0
Saved in: General.OptionsFileName
General.Light3X
X position of light source 3
Default value: 0.5
Saved in: General.OptionsFileName
General.Light3Y
Y position of light source 3
Default value: 0.3
Saved in: General.OptionsFileName
General.Light3Z
Z position of light source 3
Default value: 1
Saved in: General.OptionsFileName
General.Light3W
Divisor of the X, Y and Z coordinates of light source 3 (W=0 means infinitely far source)
Default value: 0
Saved in: General.OptionsFileName
General.Light4
Enable light source 4
Default value: 0
Saved in: General.OptionsFileName
General.Light4X
X position of light source 4
Default value: 0.5
Saved in: General.OptionsFileName
General.Light4Y
Y position of light source 4
Default value: 0.3
Saved in: General.OptionsFileName
General.Light4Z
Z position of light source 4
Default value: 1
Saved in: General.OptionsFileName
General.Light4W
Divisor of the X, Y and Z coordinates of light source 4 (W=0 means infinitely far source)
Default value: 0
Saved in: General.OptionsFileName
General.Light5
Enable light source 5
Default value: 0
Saved in: General.OptionsFileName
General.Light5X
X position of light source 5
Default value: 0.5
Saved in: General.OptionsFileName
General.Light5Y
Y position of light source 5
Default value: 0.3
Saved in: General.OptionsFileName
General.Light5Z
Z position of light source 5
Default value: 1
Saved in: General.OptionsFileName
General.Light5W
Divisor of the X, Y and Z coordinates of light source 5 (W=0 means infinitely far source)
Default value: 0
Saved in: General.OptionsFileName
General.LineWidth
Display width of lines (in pixels)
Default value: 1
Saved in: General.OptionsFileName
General.ManipulatorPositionX
Horizontal position (in pixels) of the upper left corner of the manipulator window
Default value: 650
Saved in: General.SessionFileName
General.ManipulatorPositionY
Vertical position (in pixels) of the upper left corner of the manipulator window
Default value: 150
Saved in: General.SessionFileName
General.MaxX
Maximum model coordinate along the X-axis (read-only)
Default value: 0
Saved in: -
General.MaxY
Maximum model coordinate along the Y-axis (read-only)
Default value: 0
Saved in: -
General.MaxZ
Maximum model coordinate along the Z-axis (read-only)
Default value: 0
Saved in: -
General.MenuWidth
Width (in pixels) of the menu tree
Default value: 200
Saved in: General.SessionFileName
General.MenuHeight
Height (in pixels) of the (detached) menu tree
Default value: 200
Saved in: General.SessionFileName
General.MenuPositionX
Horizontal position (in pixels) of the (detached) menu tree
Default value: 400
Saved in: General.SessionFileName
General.MenuPositionY
Vertical position (in pixels) of the (detached) menu tree
Default value: 400
Saved in: General.SessionFileName
General.MessageHeight
Height (in pixels) of the message console when it is visible (should be > 0)
Default value: 300
Saved in: General.SessionFileName
General.MinX
Minimum model coordinate along the X-axis (read-only)
Default value: 0
Saved in: -
General.MinY
Minimum model coordinate along the Y-axis (read-only)
Default value: 0
Saved in: -
General.MinZ
Minimum model coordinate along the Z-axis (read-only)
Default value: 0
Saved in: -
General.MouseHoverMeshes
Enable mouse hover on meshes
Default value: 0
Saved in: General.OptionsFileName
General.MouseSelection
Enable mouse selection
Default value: 1
Saved in: General.OptionsFileName
General.NonModalWindows
Force all control windows to be on top of the graphic window ("non-modal")
Default value: 1
Saved in: General.SessionFileName
General.NoPopup
Disable interactive dialog windows in scripts (and use default values instead)
Default value: 0
Saved in: General.OptionsFileName
General.OptionsPositionX
Horizontal position (in pixels) of the upper left corner of the option window
Default value: 650
Saved in: General.SessionFileName
General.OptionsPositionY
Vertical position (in pixels) of the upper left corner of the option window
Default value: 150
Saved in: General.SessionFileName
General.Orthographic
Orthographic projection mode (0=perspective projection)
Default value: 1
Saved in: General.OptionsFileName
General.PluginPositionX
Horizontal position (in pixels) of the upper left corner of the plugin window
Default value: 650
Saved in: General.SessionFileName
General.PluginPositionY
Vertical position (in pixels) of the upper left corner of the plugin window
Default value: 550
Saved in: General.SessionFileName
General.PluginHeight
Height (in pixels) of the plugin window
Default value: 320
Saved in: General.SessionFileName
General.PluginWidth
Width (in pixels) of the plugin window
Default value: 420
Saved in: General.SessionFileName
General.PointSize
Display size of points (in pixels)
Default value: 3
Saved in: General.OptionsFileName
General.PolygonOffsetAlwaysOn
Always apply polygon offset, instead of trying to detect when it is required
Default value: 0
Saved in: General.OptionsFileName
General.PolygonOffsetFactor
Polygon offset factor (offset = factor * DZ + r * units)
Default value: 0.5
Saved in: General.OptionsFileName
General.PolygonOffsetUnits
Polygon offset units (offset = factor * DZ + r * units)
Default value: 1
Saved in: General.OptionsFileName
General.ProgressMeterStep
Increment (in percent) of the progress meter bar
Default value: 20
Saved in: General.OptionsFileName
General.QuadricSubdivisions
Number of subdivisions used to draw points or lines as spheres or cylinders
Default value: 6
Saved in: General.OptionsFileName
General.RotationX
First Euler angle (used if Trackball=0)
Default value: 0
Saved in: -
General.RotationY
Second Euler angle (used if Trackball=0)
Default value: 0
Saved in: -
General.RotationZ
Third Euler angle (used if Trackball=0)
Default value: 0
Saved in: -
General.RotationCenterGravity
Rotate around the (pseudo) center of mass instead of (RotationCenterX, RotationCenterY, RotationCenterZ)
Default value: 1
Saved in: General.OptionsFileName
General.RotationCenterX
X coordinate of the center of rotation
Default value: 0
Saved in: -
General.RotationCenterY
Y coordinate of the center of rotation
Default value: 0
Saved in: -
General.RotationCenterZ
Z coordinate of the center of rotation
Default value: 0
Saved in: -
General.SaveOptions
Automatically save current options in General.OptionsFileName (1) or per model (2)each time you quit Gmsh?
Default value: 0
Saved in: General.SessionFileName
General.SaveSession
Automatically save session specific information in General.SessionFileName each time you quit Gmsh?
Default value: 1
Saved in: General.SessionFileName
General.ScaleX
X-axis scale factor
Default value: 1
Saved in: -
General.ScaleY
Y-axis scale factor
Default value: 1
Saved in: -
General.ScaleZ
Z-axis scale factor
Default value: 1
Saved in: -
General.Shininess
Material shininess
Default value: 0.4
Saved in: General.OptionsFileName
General.ShininessExponent
Material shininess exponent (between 0 and 128)
Default value: 40
Saved in: General.OptionsFileName
General.SmallAxes
Display the small axes
Default value: 1
Saved in: General.OptionsFileName
General.SmallAxesPositionX
X position (in pixels) of small axes (< 0: measure from right edge; >= 1e5: centered)
Default value: -60
Saved in: General.OptionsFileName
General.SmallAxesPositionY
Y position (in pixels) of small axes (< 0: measure from bottom edge; >= 1e5: centered)
Default value: -40
Saved in: General.OptionsFileName
General.SmallAxesSize
Size (in pixels) of small axes
Default value: 30
Saved in: General.OptionsFileName
General.StatisticsPositionX
Horizontal position (in pixels) of the upper left corner of the statistic window
Default value: 650
Saved in: General.SessionFileName
General.StatisticsPositionY
Vertical position (in pixels) of the upper left corner of the statistic window
Default value: 150
Saved in: General.SessionFileName
General.Stereo
Use stereo rendering
Default value: 0
Saved in: General.OptionsFileName
General.SystemMenuBar
Use the system menu bar on Mac OS X?
Default value: 1
Saved in: General.SessionFileName
General.Terminal
Should information be printed on the terminal (if available)?
Default value: 0
Saved in: General.OptionsFileName
General.Tooltips
Show tooltips in the user interface
Default value: 1
Saved in: General.OptionsFileName
General.Trackball
Use trackball rotation mode
Default value: 1
Saved in: General.OptionsFileName
General.TrackballHyperbolicSheet
Use hyperbolic sheet away from trackball center for z-rotations
Default value: 1
Saved in: General.OptionsFileName
General.TrackballQuaternion0
First trackball quaternion component (used if General.Trackball=1)
Default value: 0
Saved in: -
General.TrackballQuaternion1
Second trackball quaternion component (used if General.Trackball=1)
Default value: 0
Saved in: -
General.TrackballQuaternion2
Third trackball quaternion component (used if General.Trackball=1)
Default value: 0
Saved in: -
General.TrackballQuaternion3
Fourth trackball quaternion component (used if General.Trackball=1)
Default value: 1
Saved in: -
General.TranslationX
X-axis translation (in model units)
Default value: 0
Saved in: -
General.TranslationY
Y-axis translation (in model units)
Default value: 0
Saved in: -
General.TranslationZ
Z-axis translation (in model units)
Default value: 0
Saved in: -
General.VectorType
Default vector display type (for normals, etc.)
Default value: 4
Saved in: General.OptionsFileName
General.Verbosity
Level of information printed during processing (0=no information)
Default value: 5
Saved in: General.OptionsFileName
General.VisibilityPositionX
Horizontal position (in pixels) of the upper left corner of the visibility window
Default value: 650
Saved in: General.SessionFileName
General.VisibilityPositionY
Vertical position (in pixels) of the upper left corner of the visibility window
Default value: 150
Saved in: General.SessionFileName
General.ZoomFactor
Middle mouse button zoom acceleration factor
Default value: 4
Saved in: General.OptionsFileName
General.Color.Background
Background color
Default value: {255,255,255}
Saved in: General.OptionsFileName
General.Color.BackgroundGradient
Background gradient color
Default value: {208,215,255}
Saved in: General.OptionsFileName
General.Color.Foreground
Foreground color
Default value: {85,85,85}
Saved in: General.OptionsFileName
General.Color.Text
Text color
Default value: {0,0,0}
Saved in: General.OptionsFileName
General.Color.Axes
Axes color
Default value: {0,0,0}
Saved in: General.OptionsFileName
General.Color.SmallAxes
Small axes color
Default value: {0,0,0}
Saved in: General.OptionsFileName
General.Color.AmbientLight
Ambient light color
Default value: {25,25,25}
Saved in: General.OptionsFileName
General.Color.DiffuseLight
Diffuse light color
Default value: {255,255,255}
Saved in: General.OptionsFileName
General.Color.SpecularLight
Specular light color
Default value: {255,255,255}
Saved in: General.OptionsFileName
Print.ParameterCommand
Command parsed when the print parameter is changed
Default value: "Mesh.Clip=1; View.Clip=1; General.ClipWholeElements=1; General.Clip0D=Print.Parameter; SetChanged;"
Saved in: General.OptionsFileName
Print.Parameter
Current value of the print parameter
Default value: 0
Saved in: General.OptionsFileName
Print.ParameterFirst
First value of print parameter in loop
Default value: -1
Saved in: General.OptionsFileName
Print.ParameterLast
Last value of print parameter in loop
Default value: 1
Saved in: General.OptionsFileName
Print.ParameterSteps
Number of steps in loop over print parameter
Default value: 10
Saved in: General.OptionsFileName
Print.Background
Print background?
Default value: 0
Saved in: General.OptionsFileName
Print.CompositeWindows
Composite all window tiles in the same output image (for bitmap output only)
Default value: 0
Saved in: General.OptionsFileName
Print.DeleteTemporaryFiles
Delete temporary files used during printing
Default value: 1
Saved in: General.OptionsFileName
Print.EpsBestRoot
Try to minimize primitive splitting in BSP tree sorted PostScript/PDF output
Default value: 1
Saved in: General.OptionsFileName
Print.EpsCompress
Compress PostScript/PDF output using zlib
Default value: 0
Saved in: General.OptionsFileName
Print.EpsLineWidthFactor
Width factor for lines in PostScript/PDF output
Default value: 1
Saved in: General.OptionsFileName
Print.EpsOcclusionCulling
Cull occluded primitives (to reduce PostScript/PDF file size)
Default value: 1
Saved in: General.OptionsFileName
Print.EpsPointSizeFactor
Size factor for points in PostScript/PDF output
Default value: 1
Saved in: General.OptionsFileName
Print.EpsPS3Shading
Enable PostScript Level 3 shading
Default value: 0
Saved in: General.OptionsFileName
Print.EpsQuality
PostScript/PDF quality (0=bitmap, 1=vector (simple sort), 2=vector (accurate sort), 3=vector (unsorted)
Default value: 1
Saved in: General.OptionsFileName
Print.Format
File format (10=automatic)
Default value: 10
Saved in: General.OptionsFileName
Print.GeoLabels
Save labels in unrolled Gmsh geometries
Default value: 1
Saved in: General.OptionsFileName
Print.GeoOnlyPhysicals
Only save entities that belong to physical groups
Default value: 0
Saved in: General.OptionsFileName
Print.GifDither
Apply dithering to GIF output
Default value: 0
Saved in: General.OptionsFileName
Print.GifInterlace
Interlace GIF output
Default value: 0
Saved in: General.OptionsFileName
Print.GifSort
Sort the colormap in GIF output
Default value: 1
Saved in: General.OptionsFileName
Print.GifTransparent
Output transparent GIF image
Default value: 0
Saved in: General.OptionsFileName
Print.Height
Height of printed image; use (possibly scaled) current height if < 0
Default value: -1
Saved in: General.OptionsFileName
Print.JpegQuality
JPEG quality (between 1 and 100)
Default value: 100
Saved in: General.OptionsFileName
Print.JpegSmoothing
JPEG smoothing (between 0 and 100)
Default value: 0
Saved in: General.OptionsFileName
Print.PostElementary
Save elementary region tags in mesh statistics exported as post-processing views
Default value: 1
Saved in: General.OptionsFileName
Print.PostElement
Save element numbers in mesh statistics exported as post-processing views
Default value: 0
Saved in: General.OptionsFileName
Print.PostGamma
Save Gamma quality measure in mesh statistics exported as post-processing views
Default value: 0
Saved in: General.OptionsFileName
Print.PostEta
Save Eta quality measure in mesh statistics exported as post-processing views
Default value: 0
Saved in: General.OptionsFileName
Print.PostRho
Save Rho quality measure in mesh statistics exported as post-processing views
Default value: 0
Saved in: General.OptionsFileName
Print.PostDisto
Save Disto quality measure in mesh statistics exported as post-processing views
Default value: 0
Saved in: General.OptionsFileName
Print.TexAsEquation
Print all TeX strings as equations
Default value: 0
Saved in: General.OptionsFileName
Print.Text
Print text strings?
Default value: 1
Saved in: General.OptionsFileName
Print.Width
Width of printed image; use (possibly scaled) current width if < 0)
Default value: -1
Saved in: General.OptionsFileName


Next: , Previous: General options list, Up: Options

B.2 Geometry options list

Geometry.AutoCoherence
Should all duplicate entities be automatically removed?
Default value: 1
Saved in: General.OptionsFileName
Geometry.Clip
Enable clipping planes? (Plane[i]=2^i, i=0,...,5)
Default value: 0
Saved in: -
Geometry.CopyMeshingMethod
Copy meshing method (unstructured or transfinite) when duplicating geometrical entities?
Default value: 0
Saved in: General.OptionsFileName
Geometry.ExactExtrusion
Use exact extrusion formula in interpolations (set to 0 to allow geometrical transformations of extruded entities)
Default value: 1
Saved in: General.OptionsFileName
Geometry.ExtrudeReturnLateralEntities
Add lateral entities in lists returned by extrusion commands?
Default value: 1
Saved in: General.OptionsFileName
Geometry.ExtrudeSplinePoints
Number of control points for splines created during extrusion
Default value: 5
Saved in: General.OptionsFileName
Geometry.HideCompounds
Hide entities that make up compound entities?
Default value: 1
Saved in: General.OptionsFileName
Geometry.HighlightOrphans
Highlight orphan entities (lines connected to a single surface, etc.)?
Default value: 0
Saved in: General.OptionsFileName
Geometry.LabelType
Type of entity label (1=elementary number, 2=physical number)
Default value: 1
Saved in: General.OptionsFileName
Geometry.Light
Enable lighting for the geometry
Default value: 1
Saved in: General.OptionsFileName
Geometry.LightTwoSide
Light both sides of surfaces (leads to slower rendering)
Default value: 1
Saved in: General.OptionsFileName
Geometry.Lines
Display geometry curves?
Default value: 1
Saved in: General.OptionsFileName
Geometry.LineNumbers
Display curve numbers?
Default value: 0
Saved in: General.OptionsFileName
Geometry.LineSelectWidth
Display width of selected lines (in pixels)
Default value: 2
Saved in: General.OptionsFileName
Geometry.LineType
Display lines as solid color segments (0), 3D cylinders (1) or tapered cylinders (2)
Default value: 0
Saved in: General.OptionsFileName
Geometry.LineWidth
Display width of lines (in pixels)
Default value: 2
Saved in: General.OptionsFileName
Geometry.MatchGeomAndMesh
Matches geometries and meshes
Default value: 0
Saved in: General.OptionsFileName
Geometry.Normals
Display size of normal vectors (in pixels)
Default value: 0
Saved in: General.OptionsFileName
Geometry.NumSubEdges
Number of edge subdivisions between control points when displaying curves
Default value: 20
Saved in: General.OptionsFileName
Geometry.OCCFixDegenerated
Fix degenerated edges/faces in STEP, IGES and BRep models
Default value: 0
Saved in: General.OptionsFileName
Geometry.OCCFixSmallEdges
Fix small edges in STEP, IGES and BRep models
Default value: 0
Saved in: General.OptionsFileName
Geometry.OCCFixSmallFaces
Fix small faces in STEP, IGES and BRep models
Default value: 0
Saved in: General.OptionsFileName
Geometry.OCCSewFaces
Sew faces in STEP, IGES and BRep models
Default value: 0
Saved in: General.OptionsFileName
Geometry.OCCConnectFaces
Cut and connect faces in STEP, IGES and BRep models
Default value: 0
Saved in: General.OptionsFileName
Geometry.OffsetX
Model display offset along X-axis (in model coordinates)
Default value: 0
Saved in: -
Geometry.OffsetY
Model display offset along Y-axis (in model coordinates)
Default value: 0
Saved in: -
Geometry.OffsetZ
Model display offset along Z-axis (in model coordinates)
Default value: 0
Saved in: -
Geometry.OldCircle
Use old circle description (compatibility option for old Gmsh geometries)
Default value: 0
Saved in: General.OptionsFileName
Geometry.OldRuledSurface
Use old 3-sided ruled surface interpolation (compatibility option for old Gmsh geometries)
Default value: 0
Saved in: General.OptionsFileName
Geometry.OldNewReg
Use old newreg definition for geometrical transformations (compatibility option for old Gmsh geometries)
Default value: 1
Saved in: General.OptionsFileName
Geometry.Points
Display geometry points?
Default value: 1
Saved in: General.OptionsFileName
Geometry.PointNumbers
Display points numbers?
Default value: 0
Saved in: General.OptionsFileName
Geometry.PointSelectSize
Display size of selected points (in pixels)
Default value: 5
Saved in: General.OptionsFileName
Geometry.PointSize
Display size of points (in pixels)
Default value: 4
Saved in: General.OptionsFileName
Geometry.PointType
Display points as solid color dots (0) or 3D spheres (1)
Default value: 0
Saved in: General.OptionsFileName
Geometry.ScalingFactor
Global geometry scaling factor
Default value: 1
Saved in: General.OptionsFileName
Geometry.OrientedPhysicals
Use sign of elementary entity in physical definition as orientation indicator
Default value: 1
Saved in: General.OptionsFileName
Geometry.SnapX
Snapping grid spacing along the X-axis
Default value: 0.1
Saved in: General.OptionsFileName
Geometry.SnapY
Snapping grid spacing along the Y-axis
Default value: 0.1
Saved in: General.OptionsFileName
Geometry.SnapZ
Snapping grid spacing along the Z-axis
Default value: 0.1
Saved in: General.OptionsFileName
Geometry.Surfaces
Display geometry surfaces?
Default value: 0
Saved in: General.OptionsFileName
Geometry.SurfaceNumbers
Display surface numbers?
Default value: 0
Saved in: General.OptionsFileName
Geometry.SurfaceType
Surface display type (0=cross, 1=wireframe, 2=solid)
Default value: 2
Saved in: General.OptionsFileName
Geometry.Tangents
Display size of tangent vectors (in pixels)
Default value: 0
Saved in: General.OptionsFileName
Geometry.Tolerance
Geometrical tolerance
Default value: 1e-06
Saved in: General.OptionsFileName
Geometry.Transform
Transform model display coordinates (0=no, 1=scale)
Default value: 0
Saved in: -
Geometry.TransformXX
Element (1,1) of the 3x3 model display transformation matrix
Default value: 1
Saved in: -
Geometry.TransformXY
Element (1,2) of the 3x3 model display transformation matrix
Default value: 0
Saved in: -
Geometry.TransformXZ
Element (1,3) of the 3x3 model display transformation matrix
Default value: 0
Saved in: -
Geometry.TransformYX
Element (2,1) of the 3x3 model display transformation matrix
Default value: 0
Saved in: -
Geometry.TransformYY
Element (2,2) of the 3x3 model display transformation matrix
Default value: 1
Saved in: -
Geometry.TransformYZ
Element (2,3) of the 3x3 model display transformation matrix
Default value: 0
Saved in: -
Geometry.TransformZX
Element (3,1) of the 3x3 model display transformation matrix
Default value: 0
Saved in: -
Geometry.TransformZY
Element (3,2) of the 3x3 model display transformation matrix
Default value: 0
Saved in: -
Geometry.TransformZZ
Element (3,3) of the 3x3 model display transformation matrix
Default value: 1
Saved in: -
Geometry.Volumes
Display geometry volumes? (not implemented yet)
Default value: 0
Saved in: General.OptionsFileName
Geometry.VolumeNumbers
Display volume numbers? (not implemented yet)
Default value: 0
Saved in: General.OptionsFileName
Geometry.Color.Points
Normal geometry point color
Default value: {90,90,90}
Saved in: General.OptionsFileName
Geometry.Color.Lines
Normal geometry curve color
Default value: {0,0,255}
Saved in: General.OptionsFileName
Geometry.Color.Surfaces
Normal geometry surface color
Default value: {128,128,128}
Saved in: General.OptionsFileName
Geometry.Color.Volumes
Normal geometry volume color
Default value: {255,255,0}
Saved in: General.OptionsFileName
Geometry.Color.Selection
Selected geometry color
Default value: {255,0,0}
Saved in: General.OptionsFileName
Geometry.Color.HighlightZero
Highlight 0 color
Default value: {255,0,0}
Saved in: General.OptionsFileName
Geometry.Color.HighlightOne
Highlight 1 color
Default value: {255,150,0}
Saved in: General.OptionsFileName
Geometry.Color.HighlightTwo
Highlight 2 color
Default value: {255,255,0}
Saved in: General.OptionsFileName
Geometry.Color.Tangents
Tangent geometry vectors color
Default value: {255,255,0}
Saved in: General.OptionsFileName
Geometry.Color.Normals
Normal geometry vectors color
Default value: {255,0,0}
Saved in: General.OptionsFileName
Geometry.Color.Projection
Projection surface color
Default value: {0,255,0}
Saved in: General.OptionsFileName


Next: , Previous: Geometry options list, Up: Options

B.3 Mesh options list

Mesh.Algorithm
2D mesh algorithm (1=MeshAdapt, 2=Automatic, 5=Delaunay, 6=Frontal, 7=bamg, 8=delquad)
Default value: 2
Saved in: General.OptionsFileName
Mesh.Algorithm3D
3D mesh algorithm (1=Delaunay, 4=Frontal, 5=Frontal Delaunay, 6=Frontal Hex, 7=MMG3D, 9=R-tree)
Default value: 1
Saved in: General.OptionsFileName
Mesh.AngleSmoothNormals
Threshold angle below which normals are not smoothed
Default value: 30
Saved in: General.OptionsFileName
Mesh.AnisoMax
Maximum anisotropy of the mesh
Default value: 1e+33
Saved in: General.OptionsFileName
Mesh.AllowSwapAngle
Threshold angle (in degrees) between faces normals under which we allow an edge swap
Default value: 10
Saved in: General.OptionsFileName
Mesh.BdfFieldFormat
Field format for Nastran BDF files (0=free, 1=small, 2=large)
Default value: 1
Saved in: General.OptionsFileName
Mesh.Binary
Write mesh files in binary format (if possible)
Default value: 0
Saved in: General.OptionsFileName
Mesh.Bunin
Apply Bunin optimization on quad meshes (the parameter is the maximal size of a cavity that may be remeshed)
Default value: 0
Saved in: General.OptionsFileName
Mesh.Lloyd
Apply lloyd optimization on surface meshes
Default value: 0
Saved in: General.OptionsFileName
Mesh.SmoothCrossField
Apply n barycentric smoothing passes to the cross field
Default value: 0
Saved in: General.OptionsFileName
Mesh.CgnsImportOrder
Enable the creation of high-order mesh from CGNS structured meshes(1, 2, 4, 8, ...)
Default value: 1
Saved in: General.OptionsFileName
Mesh.ChacoArchitecture
(Adv. Chaco): Parallel architecture topology (0=hypercube, 1-3=mesh dimensions)
Default value: 1
Saved in: General.OptionsFileName
Mesh.ChacoEigensolver
(Adv. Chaco): Type of eigensolver for a spectral algorithm (0=Lanczos, 1=Multilevel RQI/Symmlq)
Default value: 1
Saved in: General.OptionsFileName
Mesh.ChacoEigTol
(Adv. Chaco): Tolerance of the eigensolver for spectral or multilevel-KL algorithms
Default value: 0.001
Saved in: General.OptionsFileName
Mesh.ChacoGlobalMethod
Chaco partitioning algorithm (1=Multilevel-KL, 2=Spectral, 4=Linear, 5=Random, 6=Scattered)
Default value: 1
Saved in: General.OptionsFileName
Mesh.ChacoHypercubeDim
(Adv. Chaco): Dimensional partitioning for a hypercube topology
Default value: 0
Saved in: General.OptionsFileName
Mesh.ChacoLocalMethod
(Adv. Chaco): Local partitioning algorithm
Default value: 1
Saved in: General.OptionsFileName
Mesh.ChacoMeshDim1
(Adv. Chaco): Number of partitions in the first dimension of a mesh topology
Default value: 1
Saved in: General.OptionsFileName
Mesh.ChacoMeshDim2
(Adv. Chaco): Number of partitions in the second dimension of a mesh topology
Default value: 1
Saved in: General.OptionsFileName
Mesh.ChacoMeshDim3
(Adv. Chaco): Number of partitions in the third dimension of a mesh topology
Default value: 1
Saved in: General.OptionsFileName
Mesh.ChacoPartitionSection
(Adv. Chaco): Partition by (1=bisection, 2=quadrisection, 3=octasection
Default value: 1
Saved in: General.OptionsFileName
Mesh.ChacoSeed
(Adv. Chaco): Seed for random number generator
Default value: 7.65432e+06
Saved in: General.OptionsFileName
Mesh.ChacoVMax
(Adv. Chaco): Maximum vertices in a coarse graph (for multilevel-KL algorithm and Multilevel RQI/Symmlq eigensolver)
Default value: 250
Saved in: General.OptionsFileName
Mesh.ChacoParamINTERNAL_VERTICES
(Adv. Chaco): Parameter INTERNAL_VERTICES
Default value: 0
Saved in: General.OptionsFileName
Mesh.ChacoParamREFINE_MAP
(Adv. Chaco): Parameter REFINE_MAP
Default value: 1
Saved in: General.OptionsFileName
Mesh.ChacoParamREFINE_PARTITION
(Adv. Chaco): Parameter REFINE_PARTITION
Default value: 0
Saved in: General.OptionsFileName
Mesh.ChacoParamTERMINAL_PROPOGATION
(Adv. Chaco): Parameter TERMINAL_PROPOGATION
Default value: 0
Saved in: General.OptionsFileName
Mesh.CharacteristicLengthExtendFromBoundary
Extend computation of mesh element sizes from the boundaries into the surfaces/volumes
Default value: 1
Saved in: General.OptionsFileName
Mesh.CharacteristicLengthFactor
Factor applied to all mesh element sizes
Default value: 1
Saved in: General.OptionsFileName
Mesh.CharacteristicLengthMin
Minimum mesh element size
Default value: 0
Saved in: General.OptionsFileName
Mesh.CharacteristicLengthMax
Maximum mesh element size
Default value: 1e+22
Saved in: General.OptionsFileName
Mesh.CharacteristicLengthFromCurvature
Automatically compute mesh element sizes from curvature (experimental)
Default value: 0
Saved in: General.OptionsFileName
Mesh.CharacteristicLengthFromPoints
Compute mesh element sizes from values given at geometry points
Default value: 1
Saved in: General.OptionsFileName
Mesh.Clip
Enable clipping planes? (Plane[i]=2^i, i=0,...,5)
Default value: 0
Saved in: -
Mesh.ColorCarousel
Mesh coloring (0=by element type, 1=by elementary entity, 2=by physical entity, 3=by partition)
Default value: 1
Saved in: General.OptionsFileName
Mesh.CpuTime
CPU time (in seconds) for the generation of the current mesh (read-only)
Default value: 0
Saved in: -
Mesh.DrawSkinOnly
Draw only the skin of 3D meshes?
Default value: 0
Saved in: General.OptionsFileName
Mesh.Dual
Display the dual mesh obtained by barycentric subdivision
Default value: 0
Saved in: General.OptionsFileName
Mesh.ElementOrder
Element order (1=linear elements, N (<6) = elements of higher order)
Default value: 1
Saved in: General.OptionsFileName
Mesh.Explode
Element shrinking factor (between 0 and 1)
Default value: 1
Saved in: General.OptionsFileName
Mesh.FlexibleTransfinite
Allow transfinite contraints to be modified for Blossom or by global mesh size factor
Default value: 0
Saved in: General.OptionsFileName
Mesh.NewtonConvergenceTestXYZ
Force inverse surface mapping algorithm (Newton-Raphson) to converge in real coordinates (experimental)
Default value: 0
Saved in: General.OptionsFileName
Mesh.Format
Mesh output format (1=msh, 2=unv, 10=automatic, 19=vrml, 27=stl, 30=mesh, 31=bdf, 32=cgns, 33=med, 40=ply2)
Default value: 10
Saved in: General.OptionsFileName
Mesh.Hexahedra
Display mesh hexahedra?
Default value: 1
Saved in: General.OptionsFileName
Mesh.HighOrderNumLayers
Number of high order mesh elements to consider for optimization
Default value: 6
Saved in: -
Mesh.HighOrderOptimize
Optimize high order meshes?
Default value: 0
Saved in: General.OptionsFileName
Mesh.HighOrderPoissonRatio
Poisson ratio of the material used in the elastic smoother for high order meshesMust be between -1.0 and 0.5, excluded
Default value: 0.33
Saved in: -
Mesh.HighOrderThresholdMin
Minimum threshold for high order element optimization
Default value: 0.1
Saved in: General.OptionsFileName
Mesh.HighOrderThresholdMax
Maximum threshold for high order element optimization
Default value: 2
Saved in: General.OptionsFileName
Mesh.HighOrderOptPrimSurfMesh
Try to fix flipped surface mesh elements in high-order optimizer
Default value: 0
Saved in: General.OptionsFileName
Mesh.LabelSampling
Label sampling rate (display one label every `LabelSampling' elements)
Default value: 1
Saved in: General.OptionsFileName
Mesh.LabelType
Type of element label (0=element number, 1=elementary entity number, 2=physical entity number, 3=partition number, 4=coordinates)
Default value: 0
Saved in: General.OptionsFileName
Mesh.LcIntegrationPrecision
Accuracy of evaluation of the LC field for 1D mesh generation
Default value: 1e-09
Saved in: General.OptionsFileName
Mesh.Light
Enable lighting for the mesh
Default value: 1
Saved in: General.OptionsFileName
Mesh.LightLines
Enable lighting for mesh lines (element edges)
Default value: 1
Saved in: General.OptionsFileName
Mesh.LightTwoSide
Light both sides of surfaces (leads to slower rendering)
Default value: 1
Saved in: General.OptionsFileName
Mesh.Lines
Display mesh lines (1D elements)?
Default value: 0
Saved in: General.OptionsFileName
Mesh.LineNumbers
Display mesh line numbers?
Default value: 0
Saved in: General.OptionsFileName
Mesh.LineWidth
Display width of mesh lines (in pixels)
Default value: 1
Saved in: General.OptionsFileName
Mesh.MeshOnlyVisible
Mesh only visible entities (experimental: use with caution!)
Default value: 0
Saved in: General.OptionsFileName
Mesh.MetisAlgorithm
METIS partitioning algorithm (1=Recursive, 2=K-way, 3=Nodal weight)
Default value: 1
Saved in: General.OptionsFileName
Mesh.MetisEdgeMatching
(Adv. METIS): Determines the matching type (1=Random, 2=Heavy-Edge, 3=Sorted Heavy-Edge)
Default value: 3
Saved in: General.OptionsFileName
Mesh.MetisRefinementAlgorithm
(Adv. METIS): Algorithm for k-way refinement (1=Random, 2=Greedy, 3=Random with minimized connectivity)
Default value: 3
Saved in: General.OptionsFileName
Mesh.MinimumCirclePoints
Minimum number of points used to mesh a circle
Default value: 7
Saved in: General.OptionsFileName
Mesh.MinimumCurvePoints
Minimum number of points used to mesh a (non-straight) curve
Default value: 3
Saved in: General.OptionsFileName
Mesh.MshFileVersion
Version of the MSH file format to use
Default value: 2.2
Saved in: General.OptionsFileName
Mesh.MshFilePartitioned
Split MSH file by mesh partition (0: no, 1: yes, 2: create physicals by partition)
Default value: 0
Saved in: General.OptionsFileName
Mesh.MultiplePassesMeshes
Do a first simple mesh and use it for complex background meshes (curvatures...)
Default value: 0
Saved in: General.OptionsFileName
Mesh.PartitionHexWeight
Weight of hexahedral element for METIS load balancing
Default value: 1
Saved in: General.OptionsFileName
Mesh.PartitionPrismWeight
Weight of prismatic element (wedge) for METIS load balancing
Default value: 1
Saved in: General.OptionsFileName
Mesh.PartitionPyramidWeight
Weight of pyramidal element for METIS load balancing
Default value: 1
Saved in: General.OptionsFileName
Mesh.PartitionQuadWeight
Weight of quadrangle for METIS load balancing
Default value: 1
Saved in: General.OptionsFileName
Mesh.PartitionTetWeight
Weight of tetrahedral element for METIS load balancing
Default value: 1
Saved in: General.OptionsFileName
Mesh.PartitionTriWeight
Weight of triangle for METIS load balancing
Default value: 1
Saved in: General.OptionsFileName
Mesh.NbHexahedra
Number of hexahedra in the current mesh (read-only)
Default value: 0
Saved in: -
Mesh.NbNodes
Number of nodes in the current mesh (read-only)
Default value: 0
Saved in: -
Mesh.NbPartitions
Number of partitions
Default value: 1
Saved in: General.OptionsFileName
Mesh.NbPrisms
Number of prisms in the current mesh (read-only)
Default value: 0
Saved in: -
Mesh.NbPyramids
Number of pyramids in the current mesh (read-only)
Default value: 0
Saved in: -
Mesh.NbQuadrangles
Number of quadrangles in the current mesh (read-only)
Default value: 0
Saved in: -
Mesh.NbTetrahedra
Number of tetrahedra in the current mesh (read-only)
Default value: 0
Saved in: -
Mesh.NbTriangles
Number of triangles in the current mesh (read-only)
Default value: 0
Saved in: -
Mesh.Normals
Display size of normal vectors (in pixels)
Default value: 0
Saved in: General.OptionsFileName
Mesh.NumSubEdges
Number of edge subdivisions when displaying high order elements
Default value: 2
Saved in: General.OptionsFileName
Mesh.Optimize
Optimize the mesh to improve the quality of tetrahedral elements
Default value: 0
Saved in: General.OptionsFileName
Mesh.OptimizeNetgen
Optimize the mesh using Netgen to improve the quality of tetrahedral elements
Default value: 0
Saved in: General.OptionsFileName
Mesh.Partitioner
Partitioner software (1=Chacho, 2=METIS)
Default value: 2
Saved in: General.OptionsFileName
Mesh.Points
Display mesh vertices (nodes)?
Default value: 0
Saved in: General.OptionsFileName
Mesh.PointNumbers
Display mesh node numbers?
Default value: 0
Saved in: General.OptionsFileName
Mesh.PointSize
Display size of mesh vertices (in pixels)
Default value: 4
Saved in: General.OptionsFileName
Mesh.PointType
Display mesh vertices as solid color dots (0) or 3D spheres (1)
Default value: 0
Saved in: General.OptionsFileName
Mesh.Prisms
Display mesh prisms?
Default value: 1
Saved in: General.OptionsFileName
Mesh.Pyramids
Display mesh pyramids?
Default value: 1
Saved in: General.OptionsFileName
Mesh.Quadrangles
Display mesh quadrangles?
Default value: 1
Saved in: General.OptionsFileName
Mesh.QualityInf
Only display elements whose quality measure is greater than QualityInf
Default value: 0
Saved in: General.OptionsFileName
Mesh.QualitySup
Only display elements whose quality measure is smaller than QualitySup
Default value: 0
Saved in: General.OptionsFileName
Mesh.QualityType
Type of quality measure (0=gamma~vol/sum_face/max_edge, 1=eta~vol^(2/3)/sum_edge^2, 2=rho~min_edge/max_edge)
Default value: 2
Saved in: General.OptionsFileName
Mesh.RadiusInf
Only display elements whose longest edge is greater than RadiusInf
Default value: 0
Saved in: General.OptionsFileName
Mesh.RadiusSup
Only display elements whose longest edge is smaller than RadiusSup
Default value: 0
Saved in: General.OptionsFileName
Mesh.RandomFactor
Random factor used in the 2D meshing algorithm (should be increased if RandomFactor * size(triangle)/size(model) approaches machine accuracy)
Default value: 1e-09
Saved in: General.OptionsFileName
Mesh.IgnorePartitionBoundary
Ignore partitions boundaries (0=no, 1=yes)
Default value: 0
Saved in: General.OptionsFileName
Mesh.RecombinationAlgorithm
Mesh recombination algorithm (0=standard, 1=blossom)
Default value: 1
Saved in: General.OptionsFileName
Mesh.RecombineAll
Apply recombination algorithm to all surfaces, ignoring per-surface spec
Default value: 0
Saved in: General.OptionsFileName
Mesh.Recombine3DAll
Apply recombination3D algorithm to all volumes, ignoring per-volume spec
Default value: 0
Saved in: General.OptionsFileName
Mesh.DoRecombinationTest
Apply recombination algorithm for test
Default value: 0
Saved in: General.OptionsFileName
Mesh.RecombinationTestHorizStart
Depth start
Default value: 1
Saved in: General.OptionsFileName
Mesh.RecombinationTestNoGreedyStrat
No greedy (global) strategies
Default value: 0
Saved in: General.OptionsFileName
Mesh.RecombinationTestNewStrat
New strategies
Default value: 0
Saved in: General.OptionsFileName
Mesh.RemeshAlgorithm
Remeshing algorithm (0=no split, 1=automatic, 2=automatic only with metis)
Default value: 0
Saved in: General.OptionsFileName
Mesh.RemeshParametrization
Remeshing using discrete parametrization (0=harmonic_circle, 1=conformal_spectral, 2=rbf, 3=harmonic_plane, 4=convex_circle, 5=convex_plane, 6=harmonic square, 7=conformal_fe
Default value: 4
Saved in: General.OptionsFileName
Mesh.RefineSteps
Number of refinement steps in the MeshAdapt-based 2D algorithms
Default value: 10
Saved in: General.OptionsFileName
Mesh.Remove4Triangles
Try to remove nodes surrounded by 4 triangles in 2D triangular meshes
Default value: 0
Saved in: General.OptionsFileName
Mesh.ReverseAllNormals
Reverse all the mesh normals (for display)
Default value: 0
Saved in: General.OptionsFileName
Mesh.SaveAll
Ignore Physical definitions and save all elements
Default value: 0
Saved in: -
Mesh.SaveElementTagType
Type of the element tag saved in mesh formats that don't support saving physical or partition ids (1=elementary, 2=physical, 3=partition)
Default value: 1
Saved in: General.OptionsFileName
Mesh.SaveParametric
Save parametric coordinates of nodes
Default value: 0
Saved in: General.OptionsFileName
Mesh.SaveGroupsOfNodes
Save groups of nodes for each physical line and surface (UNV mesh format only)
Default value: 0
Saved in: General.OptionsFileName
Mesh.ScalingFactor
Global scaling factor applied to the saved mesh
Default value: 1
Saved in: General.OptionsFileName
Mesh.SecondOrderExperimental
Use experimental code to generate second order mesh
Default value: 0
Saved in: General.OptionsFileName
Mesh.SecondOrderIncomplete
Create incomplete second order elements? (8-node quads, 20-node hexas, etc.)
Default value: 0
Saved in: General.OptionsFileName
Mesh.SecondOrderLinear
Should second order vertices simply be created by linear interpolation?
Default value: 0
Saved in: General.OptionsFileName
Mesh.Smoothing
Number of smoothing steps applied to the final mesh
Default value: 1
Saved in: General.OptionsFileName
Mesh.SmoothNormals
Smooth the mesh normals?
Default value: 0
Saved in: General.OptionsFileName
Mesh.SmoothRatio
Ratio between mesh sizes at vertices of a same edeg (used in BAMG)
Default value: 1.8
Saved in: General.OptionsFileName
Mesh.SubdivisionAlgorithm
Mesh subdivision algorithm (0=none, 1=all quadrangles, 2=all hexahedra)
Default value: 0
Saved in: General.OptionsFileName
Mesh.SurfaceEdges
Display edges of surface mesh?
Default value: 1
Saved in: General.OptionsFileName
Mesh.SurfaceFaces
Display faces of surface mesh?
Default value: 0
Saved in: General.OptionsFileName
Mesh.SurfaceNumbers
Display surface mesh element numbers?
Default value: 0
Saved in: General.OptionsFileName
Mesh.SwitchElementTags
Invert elementary and physical tags when reading the mesh
Default value: 0
Saved in: General.OptionsFileName
Mesh.Tangents
Display size of tangent vectors (in pixels)
Default value: 0
Saved in: General.OptionsFileName
Mesh.Tetrahedra
Display mesh tetrahedra?
Default value: 1
Saved in: General.OptionsFileName
Mesh.ToleranceEdgeLength
Skip a model edge in mesh generation if its length is less than user's defined tolerance
Default value: 0
Saved in: General.OptionsFileName
Mesh.Triangles
Display mesh triangles?
Default value: 1
Saved in: General.OptionsFileName
Mesh.VolumeEdges
Display edges of volume mesh?
Default value: 1
Saved in: General.OptionsFileName
Mesh.VolumeFaces
Display faces of volume mesh?
Default value: 0
Saved in: General.OptionsFileName
Mesh.VolumeNumbers
Display volume mesh element numbers?
Default value: 0
Saved in: General.OptionsFileName
Mesh.Voronoi
Display the voronoi diagram
Default value: 0
Saved in: General.OptionsFileName
Mesh.ZoneDefinition
Method for defining a zone (0=single zone, 1=by partition, 2=by physical)
Default value: 0
Saved in: General.OptionsFileName
Mesh.Color.Points
Mesh node color
Default value: {0,0,255}
Saved in: General.OptionsFileName
Mesh.Color.PointsSup
Second order mesh node color
Default value: {255,0,255}
Saved in: General.OptionsFileName
Mesh.Color.Lines
Mesh line color
Default value: {0,0,0}
Saved in: General.OptionsFileName
Mesh.Color.Triangles
Mesh triangle color (if Mesh.ColorCarousel=0)
Default value: {160,150,255}
Saved in: General.OptionsFileName
Mesh.Color.Quadrangles
Mesh quadrangle color (if Mesh.ColorCarousel=0)
Default value: {130,120,225}
Saved in: General.OptionsFileName
Mesh.Color.Tetrahedra
Mesh tetrahedron color (if Mesh.ColorCarousel=0)
Default value: {160,150,255}
Saved in: General.OptionsFileName
Mesh.Color.Hexahedra
Mesh hexahedron color (if Mesh.ColorCarousel=0)
Default value: {130,120,225}
Saved in: General.OptionsFileName
Mesh.Color.Prisms
Mesh prism color (if Mesh.ColorCarousel=0)
Default value: {232,210,23}
Saved in: General.OptionsFileName
Mesh.Color.Pyramids
Mesh pyramid color (if Mesh.ColorCarousel=0)
Default value: {217,113,38}
Saved in: General.OptionsFileName
Mesh.Color.Tangents
Tangent mesh vector color
Default value: {255,255,0}
Saved in: General.OptionsFileName
Mesh.Color.Normals
Normal mesh vector color
Default value: {255,0,0}
Saved in: General.OptionsFileName
Mesh.Color.Zero
Color 0 in color carousel
Default value: {255,120,0}
Saved in: General.OptionsFileName
Mesh.Color.One
Color 1 in color carousel
Default value: {0,255,132}
Saved in: General.OptionsFileName
Mesh.Color.Two
Color 2 in color carousel
Default value: {255,160,0}
Saved in: General.OptionsFileName
Mesh.Color.Three
Color 3 in color carousel
Default value: {0,255,192}
Saved in: General.OptionsFileName
Mesh.Color.Four
Color 4 in color carousel
Default value: {255,200,0}
Saved in: General.OptionsFileName
Mesh.Color.Five
Color 5 in color carousel
Default value: {0,216,255}
Saved in: General.OptionsFileName
Mesh.Color.Six
Color 6 in color carousel
Default value: {255,240,0}
Saved in: General.OptionsFileName
Mesh.Color.Seven
Color 7 in color carousel
Default value: {0,176,255}
Saved in: General.OptionsFileName
Mesh.Color.Eight
Color 8 in color carousel
Default value: {228,255,0}
Saved in: General.OptionsFileName
Mesh.Color.Nine
Color 9 in color carousel
Default value: {0,116,255}
Saved in: General.OptionsFileName
Mesh.Color.Ten
Color 10 in color carousel
Default value: {188,255,0}
Saved in: General.OptionsFileName
Mesh.Color.Eleven
Color 11 in color carousel
Default value: {0,76,255}
Saved in: General.OptionsFileName
Mesh.Color.Twelve
Color 12 in color carousel
Default value: {148,255,0}
Saved in: General.OptionsFileName
Mesh.Color.Thirteen
Color 13 in color carousel
Default value: {24,0,255}
Saved in: General.OptionsFileName
Mesh.Color.Fourteen
Color 14 in color carousel
Default value: {108,255,0}
Saved in: General.OptionsFileName
Mesh.Color.Fifteen
Color 15 in color carousel
Default value: {84,0,255}
Saved in: General.OptionsFileName
Mesh.Color.Sixteen
Color 16 in color carousel
Default value: {68,255,0}
Saved in: General.OptionsFileName
Mesh.Color.Seventeen
Color 17 in color carousel
Default value: {104,0,255}
Saved in: General.OptionsFileName
Mesh.Color.Eighteen
Color 18 in color carousel
Default value: {0,255,52}
Saved in: General.OptionsFileName
Mesh.Color.Nineteen
Color 19 in color carousel
Default value: {184,0,255}
Saved in: General.OptionsFileName


Next: , Previous: Mesh options list, Up: Options

B.4 Solver options list

Solver.Executable0
System command to launch solver 0
Default value: ""
Saved in: General.SessionFileName
Solver.Executable1
System command to launch solver 1
Default value: ""
Saved in: General.SessionFileName
Solver.Executable2
System command to launch solver 2
Default value: ""
Saved in: General.SessionFileName
Solver.Executable3
System command to launch solver 3
Default value: ""
Saved in: General.SessionFileName
Solver.Executable4
System command to launch solver 4
Default value: ""
Saved in: General.SessionFileName
Solver.Executable5
System command to launch solver 5
Default value: ""
Saved in: General.SessionFileName
Solver.Executable6
System command to launch solver 6
Default value: ""
Saved in: General.SessionFileName
Solver.Executable7
System command to launch solver 7
Default value: ""
Saved in: General.SessionFileName
Solver.Executable8
System command to launch solver 8
Default value: ""
Saved in: General.SessionFileName
Solver.Executable9
System command to launch solver 9
Default value: ""
Saved in: General.SessionFileName
Solver.Name0
Name of solver 0
Default value: "GetDP"
Saved in: General.SessionFileName
Solver.Name1
Name of solver 1
Default value: ""
Saved in: General.SessionFileName
Solver.Name2
Name of solver 2
Default value: ""
Saved in: General.SessionFileName
Solver.Name3
Name of solver 3
Default value: ""
Saved in: General.SessionFileName
Solver.Name4
Name of solver 4
Default value: ""
Saved in: General.SessionFileName
Solver.Name5
Name of solver 5
Default value: ""
Saved in: General.SessionFileName
Solver.Name6
Name of solver 6
Default value: ""
Saved in: General.SessionFileName
Solver.Name7
Name of solver 7
Default value: ""
Saved in: General.SessionFileName
Solver.Name8
Name of solver 8
Default value: ""
Saved in: General.SessionFileName
Solver.Name9
Name of solver 9
Default value: ""
Saved in: General.SessionFileName
Solver.RemoteLogin0
Command to login to a remote host to launch solver 0
Default value: ""
Saved in: General.SessionFileName
Solver.RemoteLogin1
Command to login to a remote host to launch solver 1
Default value: ""
Saved in: General.SessionFileName
Solver.RemoteLogin2
Command to login to a remote host to launch solver 2
Default value: ""
Saved in: General.SessionFileName
Solver.RemoteLogin3
Command to login to a remote host to launch solver 3
Default value: ""
Saved in: General.SessionFileName
Solver.RemoteLogin4
Command to login to a remote host to launch solver 4
Default value: ""
Saved in: General.SessionFileName
Solver.RemoteLogin5
Command to login to a remote host to launch solver 5
Default value: ""
Saved in: General.SessionFileName
Solver.RemoteLogin6
Command to login to a remote host to launch solver 6
Default value: ""
Saved in: General.SessionFileName
Solver.RemoteLogin7
Command to login to a remote host to launch solver 7
Default value: ""
Saved in: General.SessionFileName
Solver.RemoteLogin8
Command to login to a remote host to launch solver 8
Default value: ""
Saved in: General.SessionFileName
Solver.RemoteLogin9
Command to login to a remote host to launch solver 9
Default value: ""
Saved in: General.SessionFileName
Solver.SocketName
Base name of socket (UNIX socket if the name does not contain a colon, TCP/IP otherwise, in the form 'host:baseport'; the actual name/port is constructed by appending the unique client id. If baseport is 0, the port is chosen automatically (recommended))
Default value: ".gmshsock"
Saved in: General.OptionsFileName
Solver.AlwaysListen
Always listen to incoming connection requests?
Default value: 0
Saved in: General.OptionsFileName
Solver.AutoArchiveOutputFiles
Automatically archive output files after each computation
Default value: 0
Saved in: General.OptionsFileName
Solver.AutoCheck
Automatically check model every time a parameter is changed
Default value: 1
Saved in: General.OptionsFileName
Solver.AutoSaveDatabase
Automatically save database after each computation
Default value: 0
Saved in: General.OptionsFileName
Solver.AutoMesh
Automatically mesh if necesssary
Default value: 1
Saved in: General.OptionsFileName
Solver.AutoMergeFile
Automatically merge result files
Default value: 1
Saved in: General.OptionsFileName
Solver.AutoHideNewViews
Automcatically hide newly merged results
Default value: 0
Saved in: General.OptionsFileName
Solver.AutoShowLastStep
Automatically show the last time step in newly merged results
Default value: 1
Saved in: General.OptionsFileName
Solver.Plugins
Enable default solver plugins?
Default value: 0
Saved in: General.OptionsFileName
Solver.ShowInvisibleParameters
Show all parameters, even those marked invisible
Default value: 0
Saved in: General.OptionsFileName
Solver.Timeout
Time (in seconds) before closing the socket if no connection is happening
Default value: 5
Saved in: General.OptionsFileName


Previous: Solver options list, Up: Options

B.5 Post-processing options list

PostProcessing.AnimationDelay
Delay (in seconds) between frames in automatic animation mode
Default value: 0.1
Saved in: General.OptionsFileName
PostProcessing.AnimationCycle
Cycle through time steps (0) or views (1) for animations
Default value: 0
Saved in: General.OptionsFileName
PostProcessing.AnimationStep
Step increment for animations
Default value: 1
Saved in: General.OptionsFileName
PostProcessing.CombineRemoveOriginal
Remove original views after a Combine operation
Default value: 1
Saved in: General.OptionsFileName
PostProcessing.ForceNodeData
Try to force saving datasets as NodeData
Default value: 0
Saved in: General.OptionsFileName
PostProcessing.Format
Default file format for post-processing views (0=ASCII view, 1=binary view, 2=parsed view, 3=STL triangulation, 4=raw text, 5=Gmsh mesh, 6=MED file, 10=automatic)
Default value: 10
Saved in: General.OptionsFileName
PostProcessing.HorizontalScales
Display value scales horizontally
Default value: 1
Saved in: General.OptionsFileName
PostProcessing.Link
Post-processing view links (0=apply next option changes to selected views, 1=force same options for all selected views)
Default value: 0
Saved in: General.OptionsFileName
PostProcessing.NbViews
Current number of views merged (read-only)
Default value: 0
Saved in: -
PostProcessing.Plugins
Enable default post-processing plugins?
Default value: 1
Saved in: General.OptionsFileName
PostProcessing.Smoothing
Apply (non-reversible) smoothing to post-processing view when merged
Default value: 0
Saved in: General.OptionsFileName
View.Attributes
Optional string attributes
Default value: ""
Saved in: General.OptionsFileName
View.AxesFormatX
Number format for X-axis (in standard C form)
Default value: "%.3g"
Saved in: General.OptionsFileName
View.AxesFormatY
Number format for Y-axis (in standard C form)
Default value: "%.3g"
Saved in: General.OptionsFileName
View.AxesFormatZ
Number format for Z-axis (in standard C form)
Default value: "%.3g"
Saved in: General.OptionsFileName
View.AxesLabelX
X-axis label
Default value: ""
Saved in: General.OptionsFileName
View.AxesLabelY
Y-axis label
Default value: ""
Saved in: General.OptionsFileName
View.AxesLabelZ
Z-axis label
Default value: ""
Saved in: General.OptionsFileName
View.FileName
Default post-processing view file name
Default value: ""
Saved in: -
View.Format
Number format (in standard C form)
Default value: "%.3g"
Saved in: General.OptionsFileName
View.GeneralizedRaiseX
Generalized elevation of the view along X-axis (in model coordinates, using formula possibly containing x, y, z, s[tep], t[ime], v0, ... v8)
Default value: "v0"
Saved in: General.OptionsFileName
View.GeneralizedRaiseY
Generalized elevation of the view along Y-axis (in model coordinates, using formula possibly containing x, y, z, s[tep], t[ime], v0, ... v8)
Default value: "v1"
Saved in: General.OptionsFileName
View.GeneralizedRaiseZ
Generalized elevation of the view along Z-axis (in model coordinates, using formula possibly containing x, y, z, s[tep], t[ime], v0, ... v8)
Default value: "v2"
Saved in: General.OptionsFileName
View.Name
Default post-processing view name
Default value: ""
Saved in: -
View.Stipple0
First stippling pattern
Default value: "1*0x1F1F"
Saved in: General.OptionsFileName
View.Stipple1
Second stippling pattern
Default value: "1*0x3333"
Saved in: General.OptionsFileName
View.Stipple2
Third stippling pattern
Default value: "1*0x087F"
Saved in: General.OptionsFileName
View.Stipple3
Fourth stippling pattern
Default value: "1*0xCCCF"
Saved in: General.OptionsFileName
View.Stipple4
Fifth stippling pattern
Default value: "2*0x1111"
Saved in: General.OptionsFileName
View.Stipple5
Sixth stippling pattern
Default value: "2*0x0F0F"
Saved in: General.OptionsFileName
View.Stipple6
Seventh stippling pattern
Default value: "1*0xCFFF"
Saved in: General.OptionsFileName
View.Stipple7
Eighth stippling pattern
Default value: "2*0x0202"
Saved in: General.OptionsFileName
View.Stipple8
Ninth stippling pattern
Default value: "2*0x087F"
Saved in: General.OptionsFileName
View.Stipple9
Tenth stippling pattern
Default value: "1*0xFFFF"
Saved in: General.OptionsFileName
View.AbscissaRangeType
Ascissa scale range type (1=default, 2=custom)
Default value: 1
Saved in: General.OptionsFileName
View.AdaptVisualizationGrid
Use adaptive visualization grid (for high-order elements)?
Default value: 0
Saved in: General.OptionsFileName
View.AngleSmoothNormals
Threshold angle below which normals are not smoothed
Default value: 30
Saved in: General.OptionsFileName
View.ArrowSizeMax
Maximum display size of arrows (in pixels)
Default value: 60
Saved in: General.OptionsFileName
View.ArrowSizeMin
Minimum display size of arrows (in pixels)
Default value: 0
Saved in: General.OptionsFileName
View.AutoPosition
Position the scale or 2D plot automatically (0: manual, 1: automatic, 2: top left, 3: top right, 4: bottom left, 5: bottom right, 6: top, 7: bottom, 8: left, 9: right, 10: full, 11: top third)
Default value: 1
Saved in: General.OptionsFileName
View.Axes
Axes (0=none, 1=simple axes, 2=box, 3=full grid, 4=open grid, 5=ruler)
Default value: 0
Saved in: General.OptionsFileName
View.AxesMikado
Mikado axes style
Default value: 0
Saved in: General.OptionsFileName
View.AxesAutoPosition
Position the axes automatically
Default value: 1
Saved in: General.OptionsFileName
View.AxesMaxX
Maximum X-axis coordinate
Default value: 1
Saved in: General.OptionsFileName
View.AxesMaxY
Maximum Y-axis coordinate
Default value: 1
Saved in: General.OptionsFileName
View.AxesMaxZ
Maximum Z-axis coordinate
Default value: 1
Saved in: General.OptionsFileName
View.AxesMinX
Minimum X-axis coordinate
Default value: 0
Saved in: General.OptionsFileName
View.AxesMinY
Minimum Y-axis coordinate
Default value: 0
Saved in: General.OptionsFileName
View.AxesMinZ
Minimum Z-axis coordinate
Default value: 0
Saved in: General.OptionsFileName
View.AxesTicsX
Number of tics on the X-axis
Default value: 5
Saved in: General.OptionsFileName
View.AxesTicsY
Number of tics on the Y-axis
Default value: 5
Saved in: General.OptionsFileName
View.AxesTicsZ
Number of tics on the Z-axis
Default value: 5
Saved in: General.OptionsFileName
View.Boundary
Draw the `N minus b'-dimensional boundary of the element (N=element dimension, b=option value)
Default value: 0
Saved in: General.OptionsFileName
View.CenterGlyphs
Center glyphs (arrows, numbers, etc.)? (0=left, 1=centered, 2=right)
Default value: 1
Saved in: General.OptionsFileName
View.Clip
Enable clipping planes? (Plane[i]=2^i, i=0,...,5)
Default value: 0
Saved in: -
View.ColormapAlpha
Colormap alpha channel value (used only if != 1)
Default value: 1
Saved in: General.OptionsFileName
View.ColormapAlphaPower
Colormap alpha channel power
Default value: 0
Saved in: General.OptionsFileName
View.ColormapBeta
Colormap beta parameter (gamma = 1-beta)
Default value: 0
Saved in: General.OptionsFileName
View.ColormapBias
Colormap bias
Default value: 0
Saved in: General.OptionsFileName
View.ColormapCurvature
Colormap curvature or slope coefficient
Default value: 0
Saved in: General.OptionsFileName
View.ColormapInvert
Invert the color values, i.e., replace x with (255-x) in the colormap?
Default value: 0
Saved in: General.OptionsFileName
View.ColormapNumber
Default colormap number
Default value: 2
Saved in: General.OptionsFileName
View.ColormapRotation
Incremental colormap rotation
Default value: 0
Saved in: General.OptionsFileName
View.ColormapSwap
Swap the min/max values in the colormap?
Default value: 0
Saved in: General.OptionsFileName
View.ComponentMap0
Forced component 0 (if View.ForceComponents > 0)
Default value: 0
Saved in: General.OptionsFileName
View.ComponentMap1
Forced component 1 (if View.ForceComponents > 0)
Default value: 1
Saved in: General.OptionsFileName
View.ComponentMap2
Forced component 2 (if View.ForceComponents > 0)
Default value: 2
Saved in: General.OptionsFileName
View.ComponentMap3
Forced component 3 (if View.ForceComponents > 0)
Default value: 3
Saved in: General.OptionsFileName
View.ComponentMap4
Forced component 4 (if View.ForceComponents > 0)
Default value: 4
Saved in: General.OptionsFileName
View.ComponentMap5
Forced component 5 (if View.ForceComponents > 0)
Default value: 5
Saved in: General.OptionsFileName
View.ComponentMap6
Forced component 6 (if View.ForceComponents > 0)
Default value: 6
Saved in: General.OptionsFileName
View.ComponentMap7
Forced component 7 (if View.ForceComponents > 0)
Default value: 7
Saved in: General.OptionsFileName
View.ComponentMap8
Forced component 8 (if View.ForceComponents > 0)
Default value: 8
Saved in: General.OptionsFileName
View.CustomAbscissaMax
User-defined maximum abscissa value
Default value: 0
Saved in: -
View.CustomAbscissaMin
User-defined minimum abscissa value
Default value: 0
Saved in: -
View.CustomMax
User-defined maximum value to be displayed
Default value: 0
Saved in: -
View.CustomMin
User-defined minimum value to be displayed
Default value: 0
Saved in: -
View.DisplacementFactor
Displacement amplification
Default value: 1
Saved in: General.OptionsFileName
View.DrawHexahedra
Display post-processing hexahedra?
Default value: 1
Saved in: General.OptionsFileName
View.DrawLines
Display post-processing lines?
Default value: 1
Saved in: General.OptionsFileName
View.DrawPoints
Display post-processing points?
Default value: 1
Saved in: General.OptionsFileName
View.DrawPrisms
Display post-processing prisms?
Default value: 1
Saved in: General.OptionsFileName
View.DrawPyramids
Display post-processing pyramids?
Default value: 1
Saved in: General.OptionsFileName
View.DrawQuadrangles
Display post-processing quadrangles?
Default value: 1
Saved in: General.OptionsFileName
View.DrawScalars
Display scalar values?
Default value: 1
Saved in: General.OptionsFileName
View.DrawSkinOnly
Draw only the skin of 3D scalar views?
Default value: 0
Saved in: General.OptionsFileName
View.DrawStrings
Display post-processing annotation strings?
Default value: 1
Saved in: General.OptionsFileName
View.DrawTensors
Display tensor values?
Default value: 1
Saved in: General.OptionsFileName
View.DrawTetrahedra
Display post-processing tetrahedra?
Default value: 1
Saved in: General.OptionsFileName
View.DrawTriangles
Display post-processing triangles?
Default value: 1
Saved in: General.OptionsFileName
View.DrawVectors
Display vector values?
Default value: 1
Saved in: General.OptionsFileName
View.Explode
Element shrinking factor (between 0 and 1)
Default value: 1
Saved in: General.OptionsFileName
View.ExternalView
Index of the view used to color vector fields (-1=self)
Default value: -1
Saved in: General.OptionsFileName
View.FakeTransparency
Use fake transparency (cheaper than the real thing, but incorrect)
Default value: 0
Saved in: General.OptionsFileName
View.ForceNumComponents
Force number of components to display (see View.ComponentMapN for mapping)
Default value: 0
Saved in: General.OptionsFileName
View.GeneralizedRaiseFactor
Generalized raise amplification factor
Default value: 1
Saved in: General.OptionsFileName
View.GeneralizedRaiseView
Index of the view used for generalized raise (-1=self)
Default value: -1
Saved in: General.OptionsFileName
View.GlyphLocation
Glyph (arrow, number, etc.) location (1=center of gravity, 2=node)
Default value: 1
Saved in: General.OptionsFileName
View.Height
Height (in pixels) of the scale or 2D plot
Default value: 200
Saved in: General.OptionsFileName
View.IntervalsType
Type of interval display (1=iso, 2=continuous, 3=discrete, 4=numeric)
Default value: 2
Saved in: General.OptionsFileName
View.Light
Enable lighting for the view
Default value: 1
Saved in: General.OptionsFileName
View.LightLines
Light element edges
Default value: 1
Saved in: General.OptionsFileName
View.LightTwoSide
Light both sides of surfaces (leads to slower rendering)
Default value: 1
Saved in: General.OptionsFileName
View.LineType
Display lines as solid color segments (0) or 3D cylinders (1)
Default value: 0
Saved in: General.OptionsFileName
View.LineWidth
Display width of lines (in pixels)
Default value: 1
Saved in: General.OptionsFileName
View.MaxRecursionLevel
Maximum recursion level for adaptive views
Default value: 0
Saved in: General.OptionsFileName
View.Max
Maximum value in the view (read-only)
Default value: 0
Saved in: -
View.MaxX
Maximum view coordinate along the X-axis (read-only)
Default value: 0
Saved in: -
View.MaxY
Maximum view coordinate along the Y-axis (read-only)
Default value: 0
Saved in: -
View.MaxZ
Maximum view coordinate along the Z-axis (read-only)
Default value: 0
Saved in: -
View.Min
Minimum value in the view (read-only)
Default value: 0
Saved in: -
View.MinX
Minimum view coordinate along the X-axis (read-only)
Default value: 0
Saved in: -
View.MinY
Minimum view coordinate along the Y-axis (read-only)
Default value: 0
Saved in: -
View.MinZ
Minimum view coordinate along the Z-axis (read-only)
Default value: 0
Saved in: -
View.NbIso
Number of intervals
Default value: 10
Saved in: General.OptionsFileName
View.NbTimeStep
Number of time steps in the view (do not change this!)
Default value: 1
Saved in: -
View.NormalRaise
Elevation of the view along the normal (in model coordinates)
Default value: 0
Saved in: -
View.Normals
Display size of normal vectors (in pixels)
Default value: 0
Saved in: General.OptionsFileName
View.OffsetX
Translation of the view along X-axis (in model coordinates)
Default value: 0
Saved in: -
View.OffsetY
Translation of the view along Y-axis (in model coordinates)
Default value: 0
Saved in: -
View.OffsetZ
Translation of the view along Z-axis (in model coordinates)
Default value: 0
Saved in: -
View.PointSize
Display size of points (in pixels)
Default value: 3
Saved in: General.OptionsFileName
View.PointType
Display points as solid color dots (0), 3D spheres (1), scaled dots (2) or scaled spheres (3)
Default value: 0
Saved in: General.OptionsFileName
View.PositionX
X position (in pixels) of the scale or 2D plot (< 0: measure from right edge; >= 1e5: centered)
Default value: 100
Saved in: General.OptionsFileName
View.PositionY
Y position (in pixels) of the scale or 2D plot (< 0: measure from bottom edge; >= 1e5: centered)
Default value: 50
Saved in: General.OptionsFileName
View.RaiseX
Elevation of the view along X-axis (in model coordinates)
Default value: 0
Saved in: -
View.RaiseY
Elevation of the view along Y-axis (in model coordinates)
Default value: 0
Saved in: -
View.RaiseZ
Elevation of the view along Z-axis (in model coordinates)
Default value: 0
Saved in: -
View.RangeType
Value scale range type (1=default, 2=custom, 3=per time step)
Default value: 1
Saved in: General.OptionsFileName
View.Sampling
Element sampling rate (draw one out every `Sampling' elements)
Default value: 1
Saved in: General.OptionsFileName
View.SaturateValues
Saturate the view values to custom min and max (1=true, 0=false)
Default value: 0
Saved in: General.OptionsFileName
View.ScaleType
Value scale type (1=linear, 2=logarithmic, 3=double logarithmic)
Default value: 1
Saved in: General.OptionsFileName
View.ShowElement
Show element boundaries?
Default value: 0
Saved in: General.OptionsFileName
View.ShowScale
Show value scale?
Default value: 1
Saved in: General.OptionsFileName
View.ShowTime
Time display mode (0=hidden, 1=time value if multi-step, 2=time value always, 3=time step if multi-step, 4=time step always)
Default value: 3
Saved in: General.OptionsFileName
View.SmoothNormals
Smooth the normals?
Default value: 0
Saved in: General.OptionsFileName
View.Stipple
Stipple curves in 2D plots?
Default value: 0
Saved in: General.OptionsFileName
View.Tangents
Display size of tangent vectors (in pixels)
Default value: 0
Saved in: General.OptionsFileName
View.TargetError
Target representation error for adaptive views
Default value: 0.01
Saved in: General.OptionsFileName
View.TensorType
Tensor Visualization Type
Default value: 1
Saved in: General.OptionsFileName
View.TimeStep
Current time step displayed
Default value: 0
Saved in: -
View.TransformXX
Element (1,1) of the 3x3 coordinate transformation matrix
Default value: 1
Saved in: -
View.TransformXY
Element (1,2) of the 3x3 coordinate transformation matrix
Default value: 0
Saved in: -
View.TransformXZ
Element (1,3) of the 3x3 coordinate transformation matrix
Default value: 0
Saved in: -
View.TransformYX
Element (2,1) of the 3x3 coordinate transformation matrix
Default value: 0
Saved in: -
View.TransformYY
Element (2,2) of the 3x3 coordinate transformation matrix
Default value: 1
Saved in: -
View.TransformYZ
Element (2,3) of the 3x3 coordinate transformation matrix
Default value: 0
Saved in: -
View.TransformZX
Element (3,1) of the 3x3 coordinate transformation matrix
Default value: 0
Saved in: -
View.TransformZY
Element (3,2) of the 3x3 coordinate transformation matrix
Default value: 0
Saved in: -
View.TransformZZ
Element (3,3) of the 3x3 coordinate transformation matrix
Default value: 1
Saved in: -
View.Type
Type of plot (1=3D, 2=2D space, 3=2D time)
Default value: 1
Saved in: -
View.UseGeneralizedRaise
Use generalized raise?
Default value: 0
Saved in: General.OptionsFileName
View.VectorType
Vector display type (1=segment, 2=arrow, 3=pyramid, 4=3D arrow, 5=displacement, 6=comet)
Default value: 4
Saved in: General.OptionsFileName
View.Visible
Is the view visible?
Default value: 1
Saved in: -
View.Width
Width (in pixels) of the scale or 2D plot
Default value: 300
Saved in: General.OptionsFileName
View.Color.Points
Point color
Default value: {0,0,0}
Saved in: General.OptionsFileName
View.Color.Lines
Line color
Default value: {0,0,0}
Saved in: General.OptionsFileName
View.Color.Triangles
Triangle color
Default value: {0,0,0}
Saved in: General.OptionsFileName
View.Color.Quadrangles
Quadrangle color
Default value: {0,0,0}
Saved in: General.OptionsFileName
View.Color.Tetrahedra
Tetrahedron color
Default value: {0,0,0}
Saved in: General.OptionsFileName
View.Color.Hexahedra
Hexahedron color
Default value: {0,0,0}
Saved in: General.OptionsFileName
View.Color.Prisms
Prism color
Default value: {0,0,0}
Saved in: General.OptionsFileName
View.Color.Pyramids
Pyramid color
Default value: {0,0,0}
Saved in: General.OptionsFileName
View.Color.Tangents
Tangent vector color
Default value: {255,255,0}
Saved in: General.OptionsFileName
View.Color.Normals
Normal vector color
Default value: {255,0,0}
Saved in: General.OptionsFileName
View.Color.Text2D
2D text color
Default value: {0,0,0}
Saved in: General.OptionsFileName
View.Color.Text3D
3D text color
Default value: {0,0,0}
Saved in: General.OptionsFileName
View.Color.Axes
Axes color
Default value: {0,0,0}
Saved in: General.OptionsFileName
View.Color.Background2D
Bacground color for 2D plots
Default value: {255,255,255}
Saved in: General.OptionsFileName
View.ColorTable
Color table used to draw the view
Saved in: General.OptionsFileName


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Appendix C Compiling the source code

Stable releases and nightly source snapshots are available from http://geuz.org/gmsh/src/. You can also access the subversion repository directly:

  1. The first time you want to download the latest full source, type:
              svn co https://geuz.org/svn/gmsh/trunk gmsh
    

    You will be asked to accept the security certificate and to provide your username and password. (Use gmsh/gmsh for read-only access.)

  2. To update your local version to the latest and greatest, go in the gmsh directory and type:
              svn update
    
  3. If you have write access, to commit your changes to the central repository, go in the gmsh directory and type:
              svn commit
    

Once you have the source code, you need to run CMake to configure your build (see the README.txt file in the top-level source directory for detailed information on how to run CMake).

Each build can be configured using a series of options, to selectively enable optional modules or features. Here is the list of CMake options:

ENABLE_3M
Enable proprietary 3M extension (default: OFF)
ENABLE_ACIS
Enable ACIS geometrical models (experimental) (default: ON)
ENABLE_ANN
Enable ANN (used for fast point search in mesh/post) (default: ON)
ENABLE_BAMG
Enable Bamg 2D anisotropic mesh generator (default: ON)
ENABLE_BFGS
Enable BFGS (used by some mesh optimizers) (default: ON)
ENABLE_BLAS_LAPACK
Enable BLAS/Lapack for linear algebra (required for meshing) (default: ON)
ENABLE_BLOSSOM
Enable Blossom algorithm (needed for full quad meshing) (default: ON)
ENABLE_BUILD_LIB
Enable 'lib' target for building static Gmsh library (default: OFF)
ENABLE_BUILD_SHARED
Enable 'shared' target for building shared Gmsh library (default: OFF)
ENABLE_BUILD_DYNAMIC
Enable dynamic Gmsh executable (linked with shared lib) (default: OFF)
ENABLE_BUILD_ANDROID
Enable Android NDK library target (experimental) (default: OFF)
ENABLE_BUILD_IOS
Enable iOS (ARM) library target (experimental) (default: OFF)
ENABLE_CGNS
Enable CGNS mesh export (experimental) (default: OFF)
ENABLE_CAIRO
Enable Cairo to render fonts (experimental) (default: ON)
ENABLE_CHACO
Enable Chaco mesh partitioner (alternative to Metis) (default: ON)
ENABLE_DINTEGRATION
Enable discrete integration (needed for levelsets) (default: ON)
ENABLE_FLTK
Enable FLTK graphical user interface (requires mesh/post) (default: ON)
ENABLE_FOURIER_MODEL
Enable Fourier geometrical models (experimental) (default: OFF)
ENABLE_GMM
Enable GMM linear solvers (simple alternative to PETSc) (default: ON)
ENABLE_GRAPHICS
Enable building graphics lib even without GUI (advanced) (default: OFF)
ENABLE_KBIPACK
Enable Kbipack (neeeded by homology solver) (default: ON)
ENABLE_MATHEX
Enable math expression parser (used by plugins and options) (default: ON)
ENABLE_MED
Enable MED mesh and post file formats (default: ON)
ENABLE_MESH
Enable mesh module (required by GUI) (default: ON)
ENABLE_METIS
Enable Metis mesh partitioner (default: ON)
ENABLE_MMG3D
Enable MMG3D 3D anisotropic mesh refinement (default: ON)
ENABLE_MPEG_ENCODE
Enable built-in MPEG movie encoder (default: ON)
ENABLE_MPI
Enable MPI (mostly for parser and solver - mesh generation is sequential) (default: OFF)
ENABLE_MSVC_STATIC_RUNTIME
Enable static Visual C++ runtime (default: OFF)
ENABLE_NATIVE_FILE_CHOOSER
Enable native file chooser in GUI (default: ON)
ENABLE_NETGEN
Enable Netgen 3D frontal mesh generator (default: ON)
ENABLE_OCC
Enable Open CASCADE geometrical models (default: ON)
ENABLE_ONELAB
Enable OneLab solver interface (default: ON)
ENABLE_ONELAB_METAMODEL
Enable OneLab metamodels (experimental) (default: ON)
ENABLE_OPENMP
Enable OpenMP (experimental) (default: OFF)
ENABLE_OPTHOM
Enable high-order mesh optimization tools (default: ON)
ENABLE_OS_SPECIFIC_INSTALL
Enable OS-specific (e.g. app bundle) installation (default: ON)
ENABLE_OSMESA
Enable OSMesa for offscreen rendering (experimental) (default: OFF)
ENABLE_PARSER
Enable GEO file parser (required for .geo/.pos files) (default: ON)
ENABLE_PETSC
Enable PETSc linear solvers (required for SLEPc) (default: ON)
ENABLE_PLUGINS
Enable post-processing plugins (default: ON)
ENABLE_POST
Enable post-processing module (required by GUI) (default: ON)
ENABLE_POPPLER
Enable Poppler for displaying PDF documents (experimental) (default: OFF)
ENABLE_QT
Enable dummy QT graphical interface proof-of-concept (experimental) (default: OFF)
ENABLE_RTREE
Enable RTREE (used for quad/hex mesh generation) (default: ON)
ENABLE_SALOME
Enable Salome routines for CAD healing (default: ON)
ENABLE_SGEOM
Enable SGEOM interface to OCC (experimental) (default: OFF)
ENABLE_SLEPC
Enable SLEPc eigensolvers (required for conformal compounds) (default: ON)
ENABLE_SOLVER
Enable built-in finite element solvers (required for compounds) (default: ON)
ENABLE_TAUCS
Enable Taucs linear solver (alternative to PETSc) (default: ON)
ENABLE_TETGEN
Enable Tetgen 3D initial mesh generator (default: ON)
ENABLE_TETGEN_OLD
Enable older version of Tetgen (default: OFF)
ENABLE_VORO3D
Enable Voro3D (for hex meshing, experimental) (default: ON)
ENABLE_WRAP_JAVA
Enable generation of Java wrappers (experimental) (default: OFF)
ENABLE_WRAP_PYTHON
Enable generation of Python wrappers (default: OFF)


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Appendix D Information for developers

Gmsh is written in C++, the scripting language is parsed using Lex and Yacc (actually, Flex and Bison), and the GUI relies on OpenGL for the 3D graphics and FLTK (http://www.fltk.org) for the widget set. Gmsh's build system is based on CMake (http://www.cmake.org). Practical notes on how to compile Gmsh's source code is provided in Compiling the source code (see also Frequently asked questions).


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D.1 Source code structure

Gmsh's code is structured in several subdirectories, roughly separated between the four core modules (Geo, Mesh, Solver, Post) and associated utilities (Common, Numeric) on one hand, and the graphics (Graphics) and interface (Fltk, Parser) code on the other.

The geometry and mesh modules are based on an object-oriented model class (Geo/GModel.h), built upon abstract geometrical entity classes (Geo/GVertex.h, Geo/GEdge.h, Geo/GFace.h and Geo/GRegion.h). Concrete implementations of the geometrical entity classes are provided for each supported CAD kernel (e.g. Geo/gmshVertex.h for geometry points in Gmsh's native CAD format, or Geo/OCCVertex.h for geometry points from OpenCASCADE). The post-processing module is based on the concept of views (Post/PView.h) and abstract data containers (derived from Post/PViewData.h).


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D.2 Coding style

If you plan to contribute code to the Gmsh project, here are some easy rules to make the code easy to read/debug/maintain:

  1. Please enable full warnings for your compiler (e.g. -Wall with g++) and don't commit until there is no warning left.
  2. Use memory checking tools to detect memory leaks and other nasty memory problems. For example, you can use
  3. always use the Msg:: class to print information or errors
  4. indent your files (2 spaces) and convert all tabs to spaces
  5. follow the style used in the existing code when adding something new (spaces after commas, opening braces for functions on a separate line, opening braces for loops and tests on the same line, etc.)


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D.3 Adding a new option

To add a new option in Gmsh:

  1. create the option in the CTX class (Common/Context.h) if it's a classical option, or in the PViewOptions class (Post/PViewOptions.h) if it's a post-processing view-dependent option;
  2. in Common/DefaultOptions.h, give a name (for the parser to be able to access it), a reference to a handling routine (i.e. opt_XXX) and a default value for this option;
  3. create the handling routine opt_XXX in Common/Options.cpp (and add the prototype in Common/Options.h);
  4. optional: create the associated widget in Fltk/optionWindow.cpp;


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Appendix E Frequently asked questions


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E.1 The basics

  1. What is Gmsh?

    Gmsh is an automatic three-dimensional finite element mesh generator with built-in pre- and post-processing facilities. With Gmsh you can create or import 1D, 2D and 3D geometrical models, mesh them, launch external finite element solvers and visualize solutions. Gmsh can be used either as a stand-alone program (graphical or not) or as a C++ library.

  2. What are the terms and conditions of use?

    Gmsh is distributed under the terms of the GNU General Public License, with an exception to allow for easier linking with external libraries. See License for more information.

  3. What does 'Gmsh' mean?

    Nothing... The name was derived from a previous version called “msh” (a shortcut for “mesh”), with the “g” prefix added to differentiate it. The default mesh file format used by Gmsh still uses the .msh extension.

    In English people tend to pronounce `Gmsh' as “gee-mesh”.

  4. Where can I find more information?

    http://geuz.org/gmsh is the primary location to obtain information about Gmsh. There you will for example find the complete reference manual, a bug tracking database and a searchable archive of the Gmsh mailing list (gmsh@geuz.org).


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E.2 Installation problems

  1. Which OSes does Gmsh run on?

    Gmsh runs on Windows, Mac OS X, Linux and most Unix variants.

  2. Are there additional requirements to run Gmsh?

    You should have the OpenGL libraries installed on your system, and in the path of the library loader. A free replacement for OpenGL can be found at http://www.mesa3d.org.

  3. How do I compile Gmsh from the source code?

    You need cmake (http://www.cmake.org) and a C++ compiler. See Compiling the source code and the README.txt file in the top-level source directory for more information.

  4. Where does Gmsh save its configuration files?

    Gmsh will attempt to save temporary files and persistent configuration options first in the $GMSH_HOME directory, then in $APPDATA (on Windows) or $HOME (on other OSes), then in $TMP, and finally in $TEMP, in that order. If none of these variables are defined, Gmsh will try to save/load its configuration files from the current working directory.


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E.3 General questions

  1. Gmsh (from a binary distribution) complains about missing libraries.

    On Windows, if your system complains about missing OPENGL32.DLL or GLU32.DLL libraries, then OpenGL is not properly installed on your machine. You can download OpenGL from Microsoft's web site, or directly from http://www.opengl.org.

    On Unix try `ldd gmsh' (or `otool -L gmsh' on Mac OS X) to check if all the required shared libraries are installed on your system. If not, install them. If it still doesn't work, recompile Gmsh from the source code.

  2. Gmsh keeps re-displaying its graphics when other windows partially hide the graphical window.

    Disable opaque move in your window manager.

  3. The graphics display very slowly.

    Are you are executing Gmsh from a remote host (via the network) without GLX? You should turn double buffering off (with the `-nodb' command line option).

  4. There is an ugly “ghost triangulation” in the vector PostScript/PDF files generated by Gmsh!

    No, there isn't. This “ghost triangulation” is due to the fact that most PostScript previewers nowadays antialias the graphic primitives when they display the page on screen. (For example, in gv, you can disable antialising with the `State->Antialias' menu.) You should not see this ghost triangulation in the printed output (on paper).

  5. How can I save GIF, JPEG, ..., images?

    Just choose the appropriate format in `File->Save As'. By default Gmsh guesses the format from the file extension, so you can just type myfile.jpg in the dialog and Gmsh will automatically create a JPEG image file.

  6. How can I save MPEG, AVI, ..., animations?

    You can create simple MPEG animations by choosing MPEG as the format in `File->Save As': this allows you to loop over time steps or post-processing data sets, or to change parameters according to Print.Parameter. To create fully customized animations or to use different output formats (AVI, MP4, etc.) you should write a script. Have a look at tutorial/t8.geo or demos/anim.script for some examples.

  7. Can I change values in input fields with the mouse in the GUI?

    Yes: dragging the mouse in a numeric input field slides the value! The left button moves one step per pixel, the middle by `10*step', and the right button by `100*step'.

  8. Can I copy messages to the clipboard?

    Yes: selecting the content of an input field, or lines in the message console (`Tools->Message Console'), copies the selected text to the clipboard.


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E.4 Geometry module

  1. Does Gmsh support NURBS curves/surfaces?

    Yes, but only via STEP, IGES or BREP model import (not in .geo files). Gmsh has to be compiled with OpenCASCADE support for this to work.

  2. Gmsh is very slow when I use many transformations (Translate, Rotate, Symmetry, Extrude, etc. ). What's wrong?

    The default behavior of Gmsh is to check and suppress all duplicate entities (points, lines and surfaces) each time a transformation command is issued. This can slow down things a lot if many transformations are performed. There are two solutions to this problem:

  3. How can I display only selected parts of my model?

    Use `Tools->Visibility'. This allows you to select elementary entities and physical groups, as well as mesh elements, in a variety of ways (in a list or tree browser, by identification number, interactively, or per window).

  4. Can I edit STEP/IGES/BRep models?

    Not yet. At the moment you can only change mesh element sizes, define volumes and physical groups, or delete entities. The easiest way to do this is to merge the model in a .geo file using Merge "file.step"; and add the relevant scripting command after that. We plan to add more advanced editing features in the future (to delete entities, to create “mixed” surfaces and volumes, to export in .geo format, etc.).

  5. How can I build modular geometries?

    Define common geometrical objects and options in separate files, reusable in all your problem definition structures. Then Include the files in your main project file.


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E.5 Mesh module

  1. What should I do when the 2D unstructured algorithm fails?

    Verify that the curves in the model do not self-intersect. If `Mesh.RandomFactor*size(triangle)/size(model)' approaches machine accuracy, increase Mesh.RandomFactor.

    If everything fails file a bug report with the version of your operating system and the full geometry.

  2. What should I do when the 3D unstructured algorithm fails?

    Verify that the surfaces in your model do not self-intersect or partially overlap. If they don't, try the other 3D algorithms (`Tool->Options->Mesh->General->3D algorithm') or try to adapt the mesh element sizes in your input file so that the surface mesh better matches the geometrical details of the model.

    If nothing works, file a bug report with the version of your operating system and and the full geometry.

  3. My 2D meshes of IGES files present gaps between surfaces

    IGES files do not contain the topology of the model, and tolerance problems can thus appear when the OpenCASCADE importer cannot identify two (close) curves as actually being identical.

    The best solution is to not use IGES and use STEP instead. If you really have to use IGES, check that you don't have duplicate curves (e.g. by displaying their numbers in the GUI with `Tools->Options->Geometry->Visibility->Line numbers'). If there are duplicates, try to change the geometrical tolerance and sew the faces (see options in `Tools->Options->Geometry->General').

  4. The quality of the elements generated by the 3D algorithm is very bad.

    Use `Optimize quality' in the mesh menu.

  5. Non-recombined 3D extruded meshes sometimes fail.

    The swapping algorithm is not very clever at the moment. Try to change the surface mesh a bit, or recombine your mesh to generate prisms or hexahedra instead of tetrahedra.

  6. Does Gmsh automatically couple unstructured tetrahedral meshes and structured hexahedral meshed using pyramids?

    Only in simple geometrical cases. We need your help to improve this.

  7. Can I explicitly assign region numbers to extruded layers?

    No, this feature has been removed in Gmsh 2.0. You must use the standard entity number instead.

  8. Did you remove the elliptic mesh generator in Gmsh 2.0?

    Yes. You can achieve the same result by using the transfinite algorithm with smoothing (e.g., with Mesh.Smoothing = 10).

  9. Does Gmsh support curved elements?

    Yes, Gmsh can generate both 1st order and 2nd order elements. To generate second order elements, click on `High order' in the mesh menu after the mesh is completed. To always generate 2nd order elements, select `Generate second order elements' in the mesh option panel. From the command line, you can also use -order 2.

  10. Can I import an existing surface mesh in Gmsh and use it to build a 3D mesh?

    Yes, you can import a surface mesh in any one of the supported mesh file formats, define a volume, and mesh it. For an example see demos/sphere-discrete.geo.

  11. How do I define boundary conditions or material properties in Gmsh?

    By design, Gmsh does not try to incorporate every possible definition of boundary conditions or material properties—this is a job best left to the solver. Instead, Gmsh provides a simple mechanism to tag groups of elements, and it is up to the solver to interpret these tags as boundary conditions, materials, etc. Associating tags with elements in Gmsh is done by defining Physical entities (Physical Points, Physical Lines, Physical Surfaces and Physical Volumes). See the reference manual as well as the tutorials (in particular tutorial/t1.geo) for a detailed description and some examples.

  12. How can I display only the mesh associated with selected geometrical entities?

    See “How can I display only selected parts of my model?”.

  13. How can I “explore” a mesh (for example, to see inside a complex structure)?

    You can use `Tools->Clipping Planes' to clip the region of interest. You can define up to 6 clipping planes in Gmsh (i.e., enough to define a “cube” inside your model) and each plane can clip either the geometry, the mesh, the post-processing views, or any combination of the above. The clipping planes are defined using the four coefficients A,B,C,D of the equation A*x+B*y+C*y+D=0, which can be adjusted interactively by dragging the mouse in the input fields.

  14. What is the signification of Rho, Eta and Gamma in Tools->Statistics?

    They measure the quality of the tetrahedra in a mesh:

    Gamma ~ inscribed_radius / circumscribed_radius Eta ~ volume^(2/3) / sum_edge_length^2 Rho ~ min_edge_length / max_edge_length

    For the exact definitions, see Geo/MElement.cpp. The graphs plot the the number of elements vs. the quality measure.

  15. Why don't the vertex and/or elememt numbers on the screen match the numbers in the mesh file?

    Gmsh reindexes the mesh vertices and elements so that they are numbered in a continuous sequence in the output files. The numbers displayed on screen after mesh generation thus usually differ from the ones saved in the mesh files. To check the actual numbers saved in the output file just load the mesh file back using `File->Open'.


Next: , Previous: Mesh module questions, Up: Frequently asked questions

E.6 Solver module

  1. How do I integrate my own solver with Gmsh?

    Gmsh uses the ONELAB interface (http://www.onelab.info) to interact with external solvers. Have a look at the GetDP finite element solver (http://geuz.org/getdp) to see how this is done.

  2. Can I launch Gmsh from my solver (instead of launching my solver from Gmsh) in order to monitor a solution?

    Sure. The simplest (but rather crude) approach if to re-launch Gmsh everytime you want to visualize something (a simple C program showing how to do this is given in utils/misc/callgmsh.c). A better approach is to modify your program so that it can communicate with Gmsh over a socket (see “How do I integrate my own solver with Gmsh?” above; you can skip the option file creation). Then select `Always listen to incoming connection requests' in the solver option panel (or run gmsh with the -listen command line option) and Gmsh will always listen for your program on the Solver.SocketName socket.


Previous: Solver module questions, Up: Frequently asked questions

E.7 Post-processing module

  1. How do I compute a section of a plot?

    Use `Tools->Plugins->Cut Plane'.

  2. Can I save an isosurface to a file?

    Yes: first run `Tools->Plugins->Cut Map' to extract the isosurface, then use `View->Save As' to save the new view.

  3. Can Gmsh generate isovolumes?

    Yes, with the CutMap plugin (set the ExtractVolume option to -1 or 1 to extract the negative or positive levelset).

  4. How do I animate my plots?

    If the views contain multiple time steps, you can press the `play' button at the bottom of the graphic window, or change the time step by hand in the view option panel. You can also use the left and right arrow keys on your keyboard to change the time step in all visible views in real time.

    If you want to loop through different views instead of time steps, you can use the `Loop through views instead of time steps' option in the view option panel, or use the up and down arrow keys on your keyboard.

  5. How do I visualize a deformed mesh?

    Load a vector view containing the displacement field, and set `Vector display' to `Displacement' in `View->Options->Aspect'. If the displacement is too small (or too large), you can scale it with the `Displacement factor' option. (Remember that you can drag the mouse in all numeric input fields to slide the value!)

    Another option is to use the `General transformation expressions' (in View->Options->Offset) on a scalar view, with the displacement map selected as the data source.

  6. Can I visualize a field on a deformed mesh?

    Yes, there are several ways to do that.

    The easiest is to load two views: the first one containing a displacement field (a vector view that will be used to deform the mesh), and the second one containing the field you want to display (this view has to contain the same number of elements as the displacement view). You should then set `Vector display' to `Displacement' in the first view, as well as set `Data source' to point to the second view. (You might want to make the second view invisible, too. If you want to amplify or decrease the amount of deformation, just modify the `Displacement factor' option.)

    Another solution is to use the `General transformation expressions' (in `View->Options->Offset') on the field you want to display, with the displacement map selected as the data source.

    And yet another solution is to use the Warp plugin.

  7. Can I color the arrows representing a vector field with data from a scalar field?

    Yes: load both the vector and the scalar fields (the two views must have the same number of elements) and, in the vector field options, select the scalar view in `Data source'.

  8. Can I color isovalue surfaces with data from another scalar view?

    Yes, using either the CutMap plugin (with the `dView' option) or the Evaluate plugin.

  9. Is there a way to save animations?

    You can save simple MPEG animations directly from the `File->Save As' menu. For other formats you should write a script. Have a look at tutorial/t8.geo or demos/anim.script for some examples.

  10. Is there a way to visualize only certain components of vector/tensor fields?

    Yes, by using either the “Force field” options in `Tools->Options->View->Visibility', or by using `Tools->Plugins->MathEval'.

  11. Can I do arithmetic operations on a view? Can I perform operations involving different views?

    Yes, with the Evaluate plugin.

  12. Some plugins seem to create empty views. What's wrong?

    There can be several reasons:

    In any case, you can automatically remove all empty views with `View->Remove->Empty Views' in the GUI, or with Delete Empty Views; in a script.

  13. How can I see “inside” a complicated post-processing view?

    Use `Tools->Clipping Planes'.

    When viewing 3D scalar fields, you can also modify the colormap (`Tools->Options->View->Map') to make the iso-surfaces “transparent”: either by holding `Ctrl' while dragging the mouse to draw the alpha channel by hand, or by using the `a', `Ctrl+a', `p' and `Ctrl+p' keyboard shortcuts.

    Yet another (destructive) option is to use the ExtractVolume option in the CutSphere or CutPlane plugins.

  14. I am loading a valid 3D scalar view but Gmsh does not display anything!

    If your dataset is constant per element make sure you don't use the `Iso-values' interval type in `Tools->Options->View->Range'.


Next: , Previous: Frequently asked questions, Up: Top

Appendix F Version history

2.8.4 (Feb 7, 2014): better reproductibility of 2D meshes; new mandatory 'Name'
attribute to define onelab variables in DefineConstant[] & co; small
improvements and bug fixes.

2.8.3 (Sep 27, 2013): new quick access menu and multiple view selection in GUI;
enhanced animation creation; many small enhancements and bug fixes.

2.8.2 (Jul 16, 2013): improved high order tools interface; minor bug fixes.

2.8.1 (Jul 11, 2013): improved compound surfaces and transfinite arrangements.

2.8.0 (Jul 8, 2013): improved Delaunay point insertion; fixed mesh orientation
of plane surfaces; fixed mesh size prescribed at embedded points; improved
display of vectors at COG; new experimental text string display engines;
improved fullscreen mode; access time/step in transformations; new experimental
features: AdaptMesh and Surface In Volume; accept unicode file paths on Windows;
compilation and bug fixes.

2.7.1 (May 11, 2013): improved Delaunay point insertion; updated onelab; better
Abaqus and UNV export; small bug and compilation fixes.

2.7.0 (Mar 9, 2013): new single-window GUI, with dynamically customizable
widget tree; faster STEP/BRep import; arbitrary size image export; faster 2D
Delaunay/Frontal algorithms; full option viewer/editor; many bug fixes.

2.6.1 (Jul 15, 2012): minor improvements and bug fixes.

2.6.0 (Jun 19, 2012): new quadrilateral meshing algorithms (Blossom and
DelQuad); new solver module based on ONELAB project (requires FLTK 1.3); new
tensor field visualization modes (eigenvectors, ellipsoid, etc.); added support
for interpolation schemes in .msh file; added support for MED3 format; rescale
viewport around visible entities (shift+1:1 in GUI); unified post-processing
field export; new experimental stereo+camera visualization mode; added
experimental BAMG & MMG3D support for anisotropic mesh generation; new OCC cut &
merge algorithm imported from Salome; new ability to connect extruded meshes to
tetrahedral grids using pyramids; new homology solver; Abaqus (INP) mesh export;
new Python and Java wrappers; bug fixes and small improvements all over the
place.

2.5.0 (Oct 15, 2010): new compound geometrical entities (for remeshing and/or
trans-patch meshing); improved mesh reclassification tool; new client/server
visualization mode; new ability to watch a pattern of files to merge; new
integrated MPEG export; new option to force the type of views dynamically;
bumped mesh version format to 2.2 (small change in the meaning of the partition
tags; this only affects partitioned (i.e. parallel) meshes); renamed several
post-processing plugins (as well as plugin options) to make them easier to
understand; many bug fixes and usability improvements all over the place.

2.4.2 (Sep 21, 2009): solver code refactoring + better IDE integration.

2.4.1 (Sep 1, 2009): fixed surface mesh orientation bug introduced in 2.4.0;
mesh and graphics code refactoring, small usability enhancements and bug fixes.

2.4.0 (Aug 22, 2009): switched build system to CMake; optionally copy
transfinite mesh contraints during geometry transformations; bumped mesh version
format to 2.1 (small change in the $PhysicalNames section, where the group
dimension is now required); ported most plugins to the new post-processing API;
switched from MathEval to MathEx and Flu_Tree_Browser to Fl_Tree; small bug
fixes and improvements all over the place.

2.3.1 (Mar 18, 2009): removed GSL dependency (Gmsh now simply uses Blas and
Lapack); new per-window visibility; added support for composite window printing
and background images; fixed string option affectation in parser; fixed surface
mesh orientation for Open CASCADE models; fixed random triangle orientations in
Delaunay and Frontal algorithms.

2.3.0 (Jan 23, 2009): major graphics and GUI code refactoring; new
full-quad/hexa subdivision algorithm; improved automatic transfinite corner
selection (now also for volumes); improved visibility browser; new automatic
adaptive visualization for high-order simplices; modified arrow size, clipping
planes and transform options; many improvements and bug fixes all over the
place.

2.2.6 (Nov 21, 2008): better transfinite smoothing and automatic corner
selection; fixed high order meshing crashes on Windows and Linux; new uniform
mesh refinement (thanks Brian!); fixed various other small bugs.

2.2.5 (Oct 25, 2008): Gmsh now requires FLTK 1.1.7 or above; various small
improvements (STL and VTK mesh IO, Netgen upgrade, Visual C++ support, Fields,
Mesh.{Msh,Stl,...}Binary changed to Mesh.Bindary) and bug fixes (pyramid
interpolation, Chaco crashes).

2.2.4 (Aug 14, 2008): integrated Metis and Chaco mesh partitioners; variables
can now be deleted in geo files; added support for point datasets in model-based
postprocessing views; small bug fixes.

2.2.3 (Jul 14, 2008): enhanced clipping interface; API cleanup; fixed various
bugs (Plugin(Integrate), high order meshes, surface info crash).

2.2.2 (Jun 20, 2008): added geometrical transformations on volumes; fixed bug in
high order mesh generation.

2.2.1 (Jun 15, 2008): various small improvements (adaptive views, GUI, code
cleanup) and bug fixes (high order meshes, Netgen interface).

2.2.0 (Apr 19, 2008): new model-based post-processing backend; added MED I/O for
mesh and post-processing; fixed BDF vertex ordering for 2nd order elements;
replaced Mesh.ConstrainedBackgroundMesh with
Mesh.CharacteristicLength{FromPoints,ExtendFromBoundary}; new Fields interface;
control windows are now non-modal by default; new experimental 2D frontal
algorithm; fixed various bugs.

2.1.1 (Mar 1, 2008): small bug fixes (second order meshes, combine views, divide
and conquer crash, ...).

2.1.0 (Feb 23, 2008): new post-processing database; complete rewrite of
post-processing drawing code; improved surface mesh algorithms; improved
STEP/IGES/BREP support; new 3D mesh optimization algorithm; new default native
file choosers; fixed 'could not find extruded vertex' in extrusions; many
improvements and bug fixes all over the place.

2.0.8 (Jul 13, 2007): unused vertices are not saved in mesh files anymore; new
plugin GUI; automatic GUI font size selection; renamed
Plugin(DecomposeInSimplex) into Plugin(MakeSimplex); reintroduced enhanced
Plugin(SphericalRaise); clarified meshing algo names; new option to save groups
of nodes in UNV meshes; new background mesh infrastructure; many small
improvements and small bug fixes.

2.0.7 (Apr 3, 2007): volumes can now be defined from external CAD surfaces;
Delaunay/Tetgen algorithm is now used by default when available; re-added
support for Plot3D structured mesh format; added ability to export external CAD
models as GEO files (this only works for the limited set of geometrical
primitives available in the GEO language, of course--so trying to convert e.g. a
trimmed NURBS from a STEP file into a GEO file will fail); "lateral" entities
are now added at the end of the list returned by extrusion commands; fixed
various bugs.

2.0 (Feb 5, 2007): new geometry and mesh databases, with support for STEP and
IGES import via Open CASCADE; complete rewrite of geometry and mesh drawing
code; complete rewrite of mesh I/O layer (with new native binary MSH format and
support for import/export of I-deas UNV, Nastran BDF, STL, Medit MESH and VRML
1.0 files); added support for incomplete second order elements; new 2D and 3D
meshing algorithms; improved integration of Netgen and TetGen algorithms;
removed anisotropic meshing algorithm (as well as attractors); removed explicit
region number specification in extrusions; option changes in the graphical
interface are now applied instantaneously; added support for offscreen rendering
using OSMesa; added support for SVG output; added string labels for Physical
entities; lots of other improvements all over the place.

1.65 (May 15, 2006): new Plugin(ExtractEdges); fixed compilation errors with
gcc4.1; replaced Plugin(DisplacementRaise) and Plugin(SphericalRaise) with the
more flexible Plugin(Warp); better handling of discrete curves; new Status
command in parser; added option to renumber nodes in .msh files (to avoid holes
in the numbering sequence); fixed 2 special cases in quad->prism extrusion;
fixed saving of 2nd order hexas with negative volume; small bug fixes and
cleanups.

1.64 (Mar 18, 2006): Windows versions do no depend on Cygwin anymore; various
bug fixes and cleanups.

1.63 (Feb 01, 2006): post-processing views can now be exported as meshes;
improved background mesh handling (a lot faster, and more accurate); improved
support for input images; new Plugin(ExtractElements); small bug fixes and
enhancements.

1.62 (Jan 15, 2006): new option to draw color gradients in the background;
enhanced perspective projection mode; new "lasso" selection mode (same as
"lasso" zoom, but in selection mode); new "invert selection" button in the
visibility browser; new snapping grid when adding points in the GUI; nicer
normal smoothing; new extrude syntax (old syntax still available, but
deprecated); various small bug fixes and enhancements.

1.61 (Nov 29, 2005): added support for second order (curved) elements in
post-processor; new version (1.4) of post-processing file formats; new stippling
options for 2D plots; removed limit on allowed number of files on command line;
all "Combine" operations are now available in the parser; changed
View.ArrowLocation into View.GlyphLocation; optimized memory usage when loading
many (>1000) views; optimized loading and drawing of line meshes and 2D iso
views; optimized handling of meshes with large number of physical entities;
optimized vertex array creation for large post-processing views on
Windows/Cygwin; removed Discrete Line and Discrete Surface commands (the same
functionality can now be obtained by simply loading a mesh in .msh format);
fixed coloring by mesh partition; added option to light wireframe meshes and
views; new "mesh statistics" export format; new full-quad recombine option; new
Plugin(ModulusPhase); hexas and prisms are now always saved with positive
volume; improved interactive entity selection; new experimental Tetgen
integration; new experimental STL remeshing algorithm; various small bug fixes
and improvements.

1.60 (Mar 15, 2005): added support for discrete curves; new Window menu on Mac
OS X; generalized all octree-based plugins (CutGrid, StreamLines, Probe, etc.)
to handle all element types (and not only scalar and vector
triangles+tetrahedra); generalized Plugin(Evaluate), Plugin(Extract) and
Plugin(Annotate); enhanced clipping plane interface; new grid/axes/rulers for 3D
post-processing views (renamed the AbscissaName, NbAbscissa and AbscissaFormat
options to more general names in the process); better automatic positioning of
2D graphs; new manipulator dialog to specify rotations, translations and
scalings "by hand"; various small enhancements and bug fixes.

1.59 (Feb 06, 2005): added support for discrete (triangulated) surfaces, either
in STL format or with the new "Discrete Surface" command; added STL and Text
output format for post-processing views and STL output format for surface
meshes; all levelset-based plugins can now also compute isovolumes; generalized
Plugin(Evaluate) to handle external view data (based on the same or on a
different mesh); generalized Plugin(CutGrid); new plugins (Eigenvalues,
Gradient, Curl, Divergence); changed default colormap to match Matlab's "Jet"
colormap; new transformation matrix option for views (for non-destructive
rotations, symmetries, etc.); improved solver interface to keep the GUI
responsive during solver calls; new C++ and Python solver examples; simplified
Tools->Visibility GUI; transfinite lines with "Progression" now allow negative
line numbers to reverse the progression; added ability to retrieve Gmsh's
version number in the parser (to help write backward compatible scripts); fixed
white space in unv mesh output; fixed various small bugs.

1.58 (Jan 01, 2005): fixed UNIX socket interface on Windows (broken by the TCP
solver patch in 1.57); bumped version number of default post-processing file
formats to 1.3 (the only small modification is the handling of the end-of-string
character for text2d and text3d objects in the ASCII format); new File->Rename
menu; new colormaps+improved colormap handling; new color+min/max options in
views; new GetValue() function to ask for values interactively in scripts;
generalized For/EndFor loops in parser; new plugins (Annotate, Remove, Probe);
new text attributes in views; renamed some shortcuts; fixed TeX output for large
scenes; new option dialogs for various output formats; fixed many small memory
leaks in parser; many small enhancements to polish the graphics and the user
interface.

1.57 (Dec 23, 2004): generalized displacement maps to display arbitrary view
types; the arrows representing a vector field can now also be colored by the
values from other scalar, vector or tensor fields; new adaptive high order
visualization mode; new options (Solver.SocketCommand, Solver.NameCommand,
View.ArrowSizeProportional, View.Normals, View.Tangents and General.ClipFactor);
fixed display of undesired solver plugin popups; enhanced interactive plugin
behavior; new plugins (HarmonicToTime, Integrate, Eigenvectors); tetrahedral
mesh file reading speedup (50% faster on large meshes); large memory footprint
reduction (up to 50%) for the visualization of triangular/tetrahedral meshes;
the solver interface now supports TCP/IP connections; new generalized raise mode
(allows to use complex expressions to offset post-processing maps); upgraded
Netgen kernel to version 4.4; new optional TIME list in parsed views to specify
the values of the time steps; several bug fixes in the Elliptic mesh algorithm;
various other small bug fixes and enhancements.

1.56 (Oct 17, 2004): new post-processing option to draw a scalar view raised by
a displacement view without using Plugin(DisplacementRaise) (makes drawing
arbitrary scalar fields on deformed meshes much easier); better post-processing
menu (arbitrary number of views+scrollable+show view number); improved
view->combine; new horizontal post-processing scales; new option to draw the
mesh nodes per element; views can now also be saved in "parsed" format; fixed
various path problems on Windows; small bug fixes.

1.55 (Aug 21, 2004): added background mesh support for Triangle; meshes can now
be displayed using "smoothed" normals (like post-processing views); added GUI
for clipping planes; new interactive clipping/cutting plane definition;
reorganized the Options GUI; enhanced 3D iso computation; enhanced lighting;
many small bug fixes.

1.54 (Jul 03, 2004): integrated Netgen (3D mesh quality optimization +
alternative 3D algorithm); Extrude Surface now always automatically creates a
new volume (in the same way Extrude Point or Extrude Line create new lines and
surfaces, respectively); fixed UNV output; made the "Layers" region numbering
consistent between lines, surfaces and volumes; fixed home directory problem on
Win98; new Plugin(CutParametric); the default project file is now created in the
home directory if no current directory is defined (e.g., when double-clicking on
the icon on Windows/Mac); fixed the discrepancy between the orientation of
geometrical surfaces and the associated surface meshes; added automatic
orientation of surfaces in surface loops; generalized Plugin(Triangulate) to
handle vector and tensor views; much nicer display of discrete iso-surfaces and
custom ranges using smooth normals; small bug fixes and cleanups.

1.53 (Jun 04, 2004): completed support for second order elements in the mesh
module (line, triangles, quadrangles, tetrahedra, hexahedra, prisms and
pyramids); various background mesh fixes and enhancements; major performance
improvements in mesh and post-processing drawing routines (OpenGL vertex arrays
for tri/quads); new Plugin(Evaluate) to evaluate arbitrary expressions on
post-processing views; generalized Plugin(Extract) to handle any combination of
components; generalized "Coherence" to handle transfinite surface/volume
attributes; plugin options can now be set in the option file (like all other
options); added "undo" capability during geometry creation; rewrote the contour
guessing routines so that entities can be selected in an arbitrary order; Mac
users can now double click on geo/msh/pos files in the Finder to launch Gmsh;
removed support for FLTK 1.0; rewrote most of the code related to quadrangles;
fixed 2d elliptic algorithm; removed all OpenGL display list code and options;
fixed light positioning; new BoundingBox command to set the bounding box
explicitly; added support for inexpensive "fake" transparency mode; many code
cleanups.

1.52 (May 06, 2004): new raster ("bitmap") PostScript/EPS/PDF output formats;
new Plugin(Extract) to extract a given component from a post-processing view;
new Plugin(CutGrid) and Plugin(StreamLines); improved mesh projection on
non-planar surfaces; added support for second order tetrahedral elements; added
interactive control of element order; refined mesh entity drawing selection (and
renamed most of the corresponding options); enhanced log scale in
post-processing; better font selection; simplified View.Raise{X,Y,Z} by removing
the scaling; various bug fixes (default postscript printing mode, drawing of 3D
arrows/cylinders on Linux, default home directory on Windows, default initial
file browser directory, extrusion of points with non-normalized axes of
rotation, computation of the scene bounding box in scripts, + the usual
documentation updates).

1.51 (Feb 29, 2004): initial support for visualizing mesh partitions; integrated
version 2.0 of the MSH mesh file format; new option to compute post-processing
ranges (min/max) per time step; Multiple views can now be combined into multi
time step ones (e.g. for programs that generate data one time step at a time);
new syntax: #var[] returns the size of the list var[]; enhanced "gmsh -convert";
temporary and error files are now created in the home directory to avoid file
permission issues; new 3D arrows; better lighting support; STL facets can now be
converted into individual geometrical surfaces; many other small improvements
and bug fixes (multi timestep tensors, color by physical entity, parser cleanup,
etc.).

1.50 (Dec 06, 2003): small changes to the visibility browser + made visibility
scriptable (new Show/Hide commands); fixed (rare) crash when deleting views;
split File->Open into File->Open and File->New to behave like most other
programs; Mac versions now use the system menu bar by default (if possible);
fixed bug leading to degenerate and/or duplicate tetrahedra in extruded meshes;
fixed crash when reloading sms meshes.

1.49 (Nov 30, 2003): made Merge, Save and Print behave like Include (i.e., open
files in the same directory as the main project file if the path is relative);
new Plugin(DecomposeInSimplex); new option View.AlphaChannel to set the
transparency factor globally for a post-processing view; new "Combine Views"
command; various bug fixes and cleanups.

1.48 (Nov 23, 2003): new DisplacementRaise plugin to plot arbitrary fields on
deformed meshes; generalized CutMap, CutPlane, CutSphere and Skin plugins to
handle all kinds of elements and fields; new "Save View[n]" command to save
views from a script; many small bug fixes (configure tests for libpng, handling
of erroneous options, multi time step scalar prism drawings, copy of surface
mesh attributes, etc.).

1.47 (Nov 12, 2003): fixed extrusion of surfaces defined by only two curves; new
syntax to retrieve point coordinates and indices of entities created through
geometrical transformations; new PDF and compressed PostScript output formats;
fixed numbering of elements created with "Extrude Point/Line"; use $GMSH_HOME as
home directory if defined.

1.46 (Aug 23, 2003): fixed crash for very long command lines; new options for
setting the displacement factor and Triangle's parameters + renamed a couple of
options to more sensible names (View.VectorType, View.ArrowSize); various small
bug fixes; documentation update.

1.45 (Jun 14, 2003): small bug fixes (min/max computation for tensor views,
missing physical points in read mesh, "jumping" geometry during interactive
manipulation of large models, etc.); variable definition speedup; restored
support for second order elements in one- and two-dimensional meshes;
documentation updates.

1.44 (Apr 21, 2003): new reference manual; added support for PNG output; fixed
small configure script bugs.

1.43 (Mar 28, 2003): fixed solver interface problem on Mac OS X; new option to
specify the interactive rotation center (default is now the pseudo "center of
gravity" of the object, instead of (0,0,0)).

1.42 (Mar 19, 2003): suppressed the automatic addition of a ".geo" extension if
the file given on the command line is not recognized; added missing Layer option
for Extrude Point; fixed various small bugs.

1.41 (Mar 04, 2003): Gmsh is now licensed under the GNU General Public License;
general code cleanup (indent).

1.40 (Feb 26, 2003): various small bug fixes (mainly GSL-related).

1.39 (Feb 23, 2003): removed all non-free routines; more build system work;
implemented Von-Mises tensor display for all element types; fixed small GUI
bugs.

1.38 (Feb 17, 2003): fixed custom range selection for 3D iso graphs; new build
system based on autoconf; new image reading code to import bitmaps as
post-processing views.

1.37 (Jan 25, 2003): generalized smoothing and cuts of post-processing views;
better Windows integration (solvers, external editors, etc.); small bug fixes.

1.36 (Nov 20, 2002): enhanced view duplication (one can now use "Duplicata
View[num]" in the input file); merged all option dialogs in a new general option
window; enhanced discoverability of the view option menus; new 3D point and line
display; many small bug fixes and enhancements ("Print" format in parser,
post-processing statistics, smooth normals, save window positions, restore
default options, etc.).

1.35 (Sep 11, 2002): graphical user interface upgraded to FLTK 1.1 (tooltips,
new file chooser with multiple selection, full keyboard navigation, cut/paste of
messages, etc.); colors can be now be directly assigned to mesh entities;
initial tensor visualization; new keyboard animation (right/left arrow for time
steps; up/down arrow for view cycling); new VRML output format for surface
meshes; new plugin for spherical elevation plots; new post-processing file
format (version 1.2) supporting quadrangles, hexahedra, prisms and pyramids;
transparency is now enabled by default for post-processing plots; many small bug
fixes (read mesh, ...).

1.34 (Feb 18, 2002): improved surface mesh of non-plane surfaces; fixed
orientation of elements in 2D anisotropic algorithm; minor user interface polish
and additions (mostly in post-processing options); various small bug fixes.

1.33 (Jan 24, 2002): new parameterizable solver interface (allowing up to 5
user-defined solvers); enhanced 2D aniso algorithm; 3D initial mesh speedup.

1.32 (Oct 04, 2001): new visibility browser; better floating point exception
checks; fixed infinite looping when merging meshes in project files; various
small clean ups (degenerate 2D extrusion, view->reload, ...).

1.31 (Nov 30, 2001): corrected ellipses; PostScript output update (better
shading, new combined PS/LaTeX output format); more interface polish; fixed
extra memory allocation in 2D meshes; Physical Volume handling in unv format;
various small fixes.

1.30 (Nov 16, 2001): interface polish; fix crash when extruding quadrangles.

1.29 (Nov 12, 2001): translations and rotations can now be combined in
extrusions; fixed coherence bug in Extrude Line; various small bug fixes and
additions.

1.28 (Oct 30, 2001): corrected the 'Using Progression' attribute for tranfinite
meshes to actually match a real geometric progression; new Triangulate plugin;
new 2D graphs (space+time charts); better performance of geometrical
transformations (warning: the numbering of some automatically created entities
has changed); new text primitives in post-processing views (file format updated
to version 1.1); more robust mean plane computation and error checks; various
other small additions and clean-ups.

1.27 (Oct 05, 2001): added ability to extrude curves with Layers/Recombine
attributes; new PointSize/LineWidth options; fixed For/EndFor loops in included
files; fixed error messages (line numbers+file names) in loops and functions;
made the automatic removal of duplicate geometrical entities optional
(Geometry.AutoCoherence=0); various other small bug fixes and clean-ups.

1.26 (Sep 06, 2001): enhanced 2D anisotropic mesh generator (metric
intersections); fixed small bug in 3D initial mesh; added alternative syntax for
built-in functions (for GetDP compatibility); added line element display; Gmsh
now saves all the elements in the mesh if no physical groups are defined (or if
Mesh.SaveAll=1).

1.25 (Sep 01, 2001): fixed bug with mixed recombined/non-recombined extruded
meshes; Linux versions are now build with no optimization, due to bugs in gcc
2.95.X.

1.24 (Aug 30, 2001): fixed characteristic length interpolation for Splines;
fixed edge swapping bug in 3D initial mesh; fixed degenerated case in
geometrical extrusion (ruled surface with 3 borders); fixed generation of
degenerated hexahedra and prisms for recombined+extruded meshes; added BSplines
creation in the GUI; integrated Jonathan Shewchuk's Triangle as an alternative
isotropic 2D mesh generator; added AngleSmoothNormals to control sharp edge
display with smoothed normals; fixed random crash for lighted 3D iso surfaces.

1.23 (Aug, 2001): fixed duplicate elements generation + non-matching tetrahedra
faces in 3D extruded meshes; better display of displacement maps; fixed
interactive ellipsis construction; generalized boundary operator; added new
explode option for post-processing views; enhanced link view behavior (to update
only the changed items); added new default plugins: Skin, Transform, Smooth;
fixed various other small bugs (mostly in the post-processing module and for
extruded meshes).

1.22 (Aug 03, 2001): fixed (yet another) bug for 2D mesh in the mean plane;
fixed surface coherence bug in extruded meshes; new double logarithmic scale,
saturate value and smoothed normals option for post-processing views; plugins
are now enabled by default; three new experimental statically linked plugins:
CutMap (extracts a given iso surface from a 3D scalar map), CutPlane (cuts a 3D
scalar map with a plane section), CutSphere (cuts a 3D scalar map with a
sphere); various other bug fixes, additions and clean-ups.

1.21 (Jul 25, 2001): fixed more memory leaks; added -opt command line option to
parse definitions directly from the command line; fixed missing screen refreshes
during contour/surface/volume selection; enhanced string manipulation functions
(Sprintf, StrCat, StrPrefix); many other small fixes and clean-ups.

1.20 (Jun 14, 2001): fixed various bugs (memory leaks, functions in included
files, solver command selection, ColorTable option, duplicate nodes in extruded
meshes (not finished yet), infinite loop on empty views, orientation of
recombined quadrangles, ...); reorganized the interface menus; added constrained
background mesh and mesh visibility options; added mesh quality histograms;
changed default mesh colors; reintegrated the old command-line extrusion mesh
generator.

1.19 (May 07, 2001): fixed seg. fault for scalar simplex post-processing; new
Solver menu; interface for GetDP solver through sockets; fixed multiple scale
alignment; added some options + full option descriptions.

1.18 (Apr 26, 2001): fixed many small bugs and incoherences in post-processing;
fixed broken background mesh in 1D mesh generation.

1.17 (Apr 17, 2001): corrected physical points saving; fixed parsing of DOS
files (carriage return problems); easier geometrical selections (cursor change);
plugin manager; enhanced variable arrays (sublist selection and affectation);
line loop check; New arrow display; reduced number of 'fatal' errors + better
handling in interactive mode; fixed bug when opening meshes; enhanced File->Open
behavior for meshes and post-processing views.

1.16 (Feb 26, 2001): added single/double buffer selection (only useful for Unix
versions of Gmsh run from remote hosts without GLX); fixed a bug for recent
versions of the opengl32.dll on Windows, which caused OpenGL fonts not to show
up.

1.15 (Feb 23, 2001): added automatic visibility setting during entity selection;
corrected geometrical extrusion bug.

1.14 (Feb 17, 2001): corrected a few bugs in the GUI (most of them were
introduced in 1.13); added interactive color selection; made the option database
bidirectional (i.e. scripts now correctly update the GUI); default options can
now be saved and automatically reloaded at startup; made some changes to the
scripting syntax (PostProcessing.View[n] becomes View[n]; Offset0 becomes
OffsetX, etc.); corrected the handling of simple triangular surfaces with large
characteristic lengths in the 2D isotropic algorithm; added an ASCII to binary
post-processing view converter.

1.13 (Feb 09, 2001): added support for JPEG output on Windows.

1.12: corrected vector lines in the post-processing parsed format; corrected
animation on Windows; corrected file creation in scripts on Windows; direct
affectation of variable arrays.

1.11 (Feb 07, 2001): corrected included file loading problem.

1.10 (Feb 04, 2001): switched from Motif to FLTK for the GUI. Many small tweaks.

1.00 (Jan 15, 2001): added PPM and YUV output; corrected nested If/Endif;
Corrected several bugs for pixel output and enhanced GIF output (dithering,
transparency); slightly changed the post-processing file format to allow both
single and double precision numbers.

0.999 (Dec 20, 2000): added JPEG output and easy MPEG generation (see t8.geo in
the tutorial); clean up of export functions; small fixes; Linux versions are now
compiled with gcc 2.95.2, which should fix the problems encountered with
Mandrake 7.2.

0.998 (Dec 19, 2000): corrected bug introduced in 0.997 in the generation of the
initial 3D mesh.

0.997 (Dec 14, 2000): corrected bug in interactive surface/volume selection;
Added interactive symmetry; corrected geometrical extrusion with rotation in
degenerated or partially degenerated cases; corrected bug in 2D mesh when
meshing in the mean plane.

0.996: arrays of variables; enhanced Printf and Sprintf; Simplified options
(suppression of option arrays).

0.995 (Dec 11, 2000): totally rewritten geometrical database (performance has
been drastically improved for all geometrical transformations, and most notably
for extrusion). As a consequence, the internal numbering of geometrical entities
has changed: this will cause incompatibilities with old .geo files, and will
require a partial rewrite of your old .geo files if these files made use of
geometrical transformations. The syntax of the .geo file has also been
clarified. Many additions for scripting purposes. New extrusion mesh
generator. Preliminary version of the coupling between extruded and Delaunay
meshes. New option and procedural database. All interactive operations can be
scripted in the input files. See the last example in the tutorial for an
example. Many stability enhancements in the 2D and 3D mesh
algorithms. Performance boost of the 3D algorithm. Gmsh is still slow, but the
performance becomes acceptable. An average 1000 tetrahedra/second is obtained on
a 600Mhz computer for a mesh of one million tetrahedra. New anisotropic 2D mesh
algorithm. New (ASCII and binary) post-processing file format and clarified mesh
file format. New handling for interactive rotations (trackball mode). New
didactic interactive mesh construction (watch the Delaunay algorithm in real
time on complex geometries: that's exciting ;-). And many, many bug fixes and
cleanups.

0.992 (Nov 13, 2000): corrected recombined extrusion; corrected ellipses; added
simple automatic animation of post-processing maps; fixed various bugs.

0.991 (Oct 24, 2000): fixed a serious allocation bug in 2D algorithm, which
caused random crashes. All users should upgrade to 0.991.

0.990: bug fix in non-recombined 3D transfinite meshes.

0.989 (Sep 01, 2000): added ability to reload previously saved meshes; some new
command line options; reorganization of the scale menu; GIF output.

0.987: fixed bug with smoothing (leading to the possible generation of erroneous
3d meshes); corrected bug for mixed 3D meshes; moved the 'toggle view link'
option to Opt->Postprocessing_Options.

0.986: fixed overlay problems; SGI version should now also run on 32 bits
machines; fixed small 3d mesh bug.

0.985: corrected colormap bug on HP, SUN, SGI and IBM versions; corrected small
initialization bug in postscript output.

0.984: corrected bug in display lists; added some options in Opt->General.

0.983: corrected some seg. faults in interactive mode; corrected bug in
rotations; changed default window sizes for better match with 1024x768 screens
(default X resources can be changed: see ex03.geo).

0.982: lighting for mesh and post-processing; corrected 2nd order mesh on non
plane surfaces; added example 13.


Next: , Previous: Version history, Up: Top

Appendix G Copyright and credits

                 Gmsh is copyright (C) 1997-2014

                       Christophe Geuzaine
                     <cgeuzaine at ulg.ac.be>

                               and

                      Jean-Francois Remacle
              <jean-francois.remacle at uclouvain.be>

Code contributions to Gmsh have been provided by David Colignon (colormaps),
Emilie Marchandise (compound geometrical entities), Gaetan Bricteux (Gauss
integration and levelsets), Jacques Lechelle (DIFFPACK mesh format), Jonathan
Lambrechts (fields, solver), Jozef Vesely (help with Tetgen integration), Koen
Hillewaert (high order elements), Laurent Stainier (eigenvalue solvers, tensor
display and MacOS bits), Marc Ume (original list code), Mark van Doesburg (Open
CASCADE face connection), Matt Gundry (Plot3d mesh format), Matti Pellikka (Cell
complex and Homology solver), Nicolas Tardieu (help with Netgen integration),
Pascale Noyret (MED mesh format), Pierre Badel (root finding and minimization),
Ruth Sabariego (pyramids), Stephen Guzik (CGNS and partitioners), Bastien
Gorissen (parallel remote post-processing), Eric Bechet (solver), Gilles
Marckmann (camera and stero mode), Ashish Negi (Salome/Netgen CAD healing),
Trevor Strickler (structured/unstructured coupling with pyramids), Amaury Johnen
(Bezier), Benjamin Ruard (Java wrappers). See comments in the sources for more
information. If we forgot to list your contributions please send us an email!

The AVL tree code (Common/avl.*) and the YUV image code (Graphics/gl2yuv.*) are
copyright (C) 1988-1993, 1995 The Regents of the University of
California. Permission to use, copy, modify, and distribute this software and
its documentation for any purpose and without fee is hereby granted, provided
that the above copyright notice appear in all copies and that both that
copyright notice and this permission notice appear in supporting documentation,
and that the name of the University of California not be used in advertising or
publicity pertaining to distribution of the software without specific, written
prior permission. The University of California makes no representations about
the suitability of this software for any purpose. It is provided "as is" without
express or implied warranty.

The trackball code (Graphics/Trackball.*) is copyright (C) 1993, 1994, Silicon
Graphics, Inc. ALL RIGHTS RESERVED. Permission to use, copy, modify, and
distribute this software for any purpose and without fee is hereby granted,
provided that the above copyright notice appear in all copies and that both the
copyright notice and this permission notice appear in supporting documentation,
and that the name of Silicon Graphics, Inc. not be used in advertising or
publicity pertaining to distribution of the software without specific, written
prior permission.

The GIF and PPM routines (Graphics/gl2gif.cpp) are based on code copyright (C)
1989, 1991, Jef Poskanzer. Permission to use, copy, modify, and distribute this
software and its documentation for any purpose and without fee is hereby
granted, provided that the above copyright notice appear in all copies and that
both that copyright notice and this permission notice appear in supporting
documentation.  This software is provided "as is" without express or implied
warranty.

The colorbar widget (Fltk/Colorbar_Window.cpp) was inspired by code from the
Vis5d program for visualizing five dimensional gridded data sets, copyright (C)
1990-1995, Bill Hibbard, Brian Paul, Dave Santek, and Andre Battaiola.

This version of Gmsh may contain code (in the contrib/ANN subdirectory)
copyright (C) 1997-2005 University of Maryland and Sunil Arya and David Mount:
check the configuration options.

This version of Gmsh may contain code (in the contrib/Chaco subdirectory)
written by Bruce Hendrickson and Robert Leland at Sandia National Laboratories
under US Department of Energy contract DE-AC04-76DP00789 and is copyrighted by
Sandia Corporation: check the configuration options.

This version of Gmsh may contain code (in the contrib/gmm subdirectory)
copyright (C) 2002-2008 Yves Renard: check the configuration options.

This version of Gmsh may contain code (in the contrib/kbipack subdirectory)
copyright (C) 2005 Saku Suuriniemi: check the configuration options.

This version of Gmsh may contain code (in the contrib/MathEx subdirectory) based
in part on the work of the SSCILIB Library, copyright (C) 2000-2003 Sadao
Massago: check the configuration options.

This version of Gmsh may contain code (in the contrib/Metis subdirectory)
written by George Karypis (karypis at cs.umn.edu), copyright (C) 1998 Regents of
the University of Minnesota: check the configuration options.

This version of Gmsh may contain code (in the contrib/mpeg_encode subdirectory)
copyright (c) 1995 The Regents of the University of California: check the
configuration options.

This version of Gmsh may contain code (in the contrib/Netgen subdirectory)
copyright (C) 1994-2004 Joachim Sch"oberl: check the configuration options.

This version of Gmsh may contain code (in the contrib/Tetgen subdirectory)
copyright (C) 2002-2007 Hang Si: check the configuration options.

This version of Gmsh may contain code (in the contrib/Salome subdirectory)
copyright (C) 2003 OPEN CASCADE, EADS/CCR, LIP6, CEA/DEN, CEDRAT, EDF R& D, LEG,
PRINCIPIA R& D, BUREAU VERITAS: check the configuration options.

This version of Gmsh may contain code (in the contrib/bamg subdirectory) from
Freefem++ copyright (C) Frederic Hecht: check the configuration options.

This version of Gmsh may contain code (in the contrib/lbfgs subdirectory) (C)
Sergey Bochkanov (ALGLIB project): check the configuration options.

This version of Gmsh may contain code (in the contrib/mmg3d subdirectory) from
MMG3D Version 4.0 (C) 2004-2011 Cecile Dobrzynski and Pascal Frey (IPB - UPMC -
INRIA): check the configuration options.

This version of Gmsh may contain code (in the contrib/Blossom subdirectory)
copyright (C) 1995-1997 Bill Cook et al.: check the configuration options.

Special thanks to Bill Spitzak, Michael Sweet, Matthias Melcher, Greg Ercolano
and others for the Fast Light Tool Kit on which Gmsh's GUI is based. See
http://www.fltk.org for more info on this excellent object-oriented,
cross-platform toolkit.

Special thanks also to EDF for funding the Open CASCADE and MED integration.

Thanks to the following folks who have contributed by providing fresh ideas on
theoretical or programming topics, who have sent patches, requests for changes
or improvements, or who gave us access to exotic machines for testing Gmsh: Juan
Abanto, Olivier Adam, Guillaume Alleon, Laurent Champaney, Pascal Dupuis,
Patrick Dular, Philippe Geuzaine, Johan Gyselinck, Francois Henrotte, Benoit
Meys, Nicolas Moes, Osamu Nakamura, Chad Schmutzer, Jean-Luc Fl'ejou, Xavier
Dardenne, Christophe Prud'homme, Sebastien Clerc, Jose Miguel Pasini, Philippe
Lussou, Jacques Kools, Bayram Yenikaya, Peter Hornby, Krishna Mohan Gundu,
Christopher Stott, Timmy Schumacher, Carl Osterwisch, Bruno Frackowiak, Philip
Kelleners, Romuald Conty, Renaud Sizaire, Michel Benhamou, Tom De Vuyst, Kris
Van den Abeele, Simon Vun, Simon Corbin, Thomas De-Soza, Marcus Drosson, Antoine
Dechaume, Jose Paulo Moitinho de Almeida, Thomas Pinchard, Corrado Chisari, Axel
Hackbarth, Peter Wainwright, Jiri Hnidek, Thierry Thomas, Konstantinos Poulios,
Laurent Van Miegroet, Shahrokh Ghavamian, Geordie McBain, Jose Paulo Moitinho de
Almeida, Guillaume Demesy, Wendy Merks-Swolfs.


Next: , Previous: Copyright and credits, Up: Top

Appendix H License

Gmsh is provided under the terms of the GNU General Public License
(GPL), Version 2 or later, with the following exception:

  The copyright holders of Gmsh give you permission to combine Gmsh
  with code included in the standard release of TetGen (from Hang 
  Si), Netgen (from Joachim Sch"oberl), Chaco (from Bruce Hendrickson
  and Robert Leland at Sandia National Laboratories), METIS (from
  George Karypis at the University of Minnesota) and OpenCASCADE
  (from Open CASCADE S.A.S) under their respective licenses. You may
  copy and distribute such a system following the terms of the GNU 
  GPL for Gmsh and the licenses of the other code concerned, provided
  that you include the source code of that other code when and as the
  GNU GPL requires distribution of source code.

  Note that people who make modified versions of Gmsh are not
  obligated to grant this special exception for their modified
  versions; it is their choice whether to do so. The GNU General
  Public License gives permission to release a modified version
  without this exception; this exception also makes it possible to
  release a modified version which carries forward this exception.

End of exception.

		    GNU GENERAL PUBLIC LICENSE
		       Version 2, June 1991

 Copyright (C) 1989, 1991 Free Software Foundation, Inc.
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 Everyone is permitted to copy and distribute verbatim copies
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FOR THE PROGRAM, TO THE EXTENT PERMITTED BY APPLICABLE LAW.  EXCEPT WHEN
OTHERWISE STATED IN WRITING THE COPYRIGHT HOLDERS AND/OR OTHER PARTIES
PROVIDE THE PROGRAM "AS IS" WITHOUT WARRANTY OF ANY KIND, EITHER EXPRESSED
OR IMPLIED, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.  THE ENTIRE RISK AS
TO THE QUALITY AND PERFORMANCE OF THE PROGRAM IS WITH YOU.  SHOULD THE
PROGRAM PROVE DEFECTIVE, YOU ASSUME THE COST OF ALL NECESSARY SERVICING,
REPAIR OR CORRECTION.

  12. IN NO EVENT UNLESS REQUIRED BY APPLICABLE LAW OR AGREED TO IN WRITING
WILL ANY COPYRIGHT HOLDER, OR ANY OTHER PARTY WHO MAY MODIFY AND/OR
REDISTRIBUTE THE PROGRAM AS PERMITTED ABOVE, BE LIABLE TO YOU FOR DAMAGES,
INCLUDING ANY GENERAL, SPECIAL, INCIDENTAL OR CONSEQUENTIAL DAMAGES ARISING
OUT OF THE USE OR INABILITY TO USE THE PROGRAM (INCLUDING BUT NOT LIMITED
TO LOSS OF DATA OR DATA BEING RENDERED INACCURATE OR LOSSES SUSTAINED BY
YOU OR THIRD PARTIES OR A FAILURE OF THE PROGRAM TO OPERATE WITH ANY OTHER
PROGRAMS), EVEN IF SUCH HOLDER OR OTHER PARTY HAS BEEN ADVISED OF THE
POSSIBILITY OF SUCH DAMAGES.

		     END OF TERMS AND CONDITIONS

	    How to Apply These Terms to Your New Programs

  If you develop a new program, and you want it to be of the greatest
possible use to the public, the best way to achieve this is to make it
free software which everyone can redistribute and change under these terms.

  To do so, attach the following notices to the program.  It is safest
to attach them to the start of each source file to most effectively
convey the exclusion of warranty; and each file should have at least
the "copyright" line and a pointer to where the full notice is found.

    <one line to give the program's name and a brief idea of what it does.>
    Copyright (C) <year>  <name of author>

    This program is free software; you can redistribute it and/or modify
    it under the terms of the GNU General Public License as published by
    the Free Software Foundation; either version 2 of the License, or
    (at your option) any later version.

    This program is distributed in the hope that it will be useful,
    but WITHOUT ANY WARRANTY; without even the implied warranty of
    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
    GNU General Public License for more details.

    You should have received a copy of the GNU General Public License
    along with this program; if not, write to the Free Software
    Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA


Also add information on how to contact you by electronic and paper mail.

If the program is interactive, make it output a short notice like this
when it starts in an interactive mode:

    Gnomovision version 69, Copyright (C) year name of author
    Gnomovision comes with ABSOLUTELY NO WARRANTY; for details type `show w'.
    This is free software, and you are welcome to redistribute it
    under certain conditions; type `show c' for details.

The hypothetical commands `show w' and `show c' should show the appropriate
parts of the General Public License.  Of course, the commands you use may
be called something other than `show w' and `show c'; they could even be
mouse-clicks or menu items--whatever suits your program.

You should also get your employer (if you work as a programmer) or your
school, if any, to sign a "copyright disclaimer" for the program, if
necessary.  Here is a sample; alter the names:

  Yoyodyne, Inc., hereby disclaims all copyright interest in the program
  `Gnomovision' (which makes passes at compilers) written by James Hacker.

  <signature of Ty Coon>, 1 April 1989
  Ty Coon, President of Vice

This General Public License does not permit incorporating your program into
proprietary programs.  If your program is a subroutine library, you may
consider it more useful to permit linking proprietary applications with the
library.  If this is what you want to do, use the GNU Library General
Public License instead of this License.


Next: , Previous: License, Up: Top

Concept index


Previous: Concept index, Up: Top

Syntax index


Footnotes

[1] Note that mixing structured volume grids with unstructured volume grids generated with the default 3D Delaunay algorithm can result, in certain cases, to non-conform surface meshes on their shared boundary. If this happens, you may consider using the frontal algorithm for the unstructured part.

[2] Nearly all the interactive commands have keyboard shortcuts: see Keyboard shortcuts, or select `Help->Keyboard and Mouse Usage' in the menu. For example, to quickly save a mesh, you can press Ctrl+Shift+s.

[3] If you compile Gmsh without the GUI (see Compiling the source code), this is the only mode you have access to.

[4] For compatibility with GetDP (http://geuz.org/getdp/), parentheses can be replaced by brackets [] in Str and Sprintf.

[5] The affectation operators are introduced in General commands.

[6] For compatibility with GetDP (http://geuz.org/getdp/), parentheses can be replaced by brackets [].

[7] For compatibility purposes, the behavior of newl, news, newv and newreg can be modified with the Geometry.OldNewReg option (see Geometry options list).

[8] R. A. Dwyer, A simple divide-and-conquer algorithm for computing Delaunay triangulations in O(n log n) expected time, In Proceedings of the second annual symposium on computational geometry, Yorktown Heights, 2–4 June 1986.

[9] N. P. Weatherill, The integrity of geometrical boundaries in the two-dimensional Delaunay triangulation, Commun. Appl. Numer. Methods 6(2), pp. 101–109, 1990.

[10] C. Geuzaine and J.-F. Remacle, Gmsh: a three-dimensional finite element mesh generator with built-in pre- and post-processing facilities, International Journal for Numerical Methods in Engineering 79(11), pp. 1309–1331, 2009.

[11] P.-L. George and P. Frey, Mesh generation, Hermes, Lyon, 2000.

[12] S. Rebay, Efficient unstructured mesh generation by means of Delaunay triangulation and Bowyer-Watson algorithm, J. Comput. Phys. 106, pp. 25–138, 1993.

[13] H. Si, Tetgen: a quality tetrahedral mesh generator and three-dimensional Delaunay triangulator, 2004.

[14] J. Schoeberl, Netgen, an advancing front 2d/3d-mesh generator based on abstract rules, Comput. Visual. Sci., 1, pp. 41–52, 1997.

[15] This behaviour was introduced in Gmsh 2.0. In older versions, both the elementary and the physical region numbers would be set to the identification number of the elementary region.