[Gmsh] Salome -> STEP -> gmsh

Bart Vandewoestyne Bart.Vandewoestyne at telenet.be
Thu Mar 24 13:55:04 CET 2011


Hello list,

I'm still playing around with Salome, STEP files and gmsh, but
can't seem to import spheres correctly into gmsh.

A cube works fine.  The Salome file is at

  http://www.kuleuven-kortrijk.be/~bartv/cube.hdf

after exporting it to a STEP file with Salome, i get

  http://www.kuleuven-kortrijk.be/~bartv/cube.step

which i can mesh correctly with

  gmsh -3 cube.step

resulting in

  http://www.kuleuven-kortrijk.be/~bartv/cube.msh

If, however, I do the same with a sphere, then I get

  bartv at sonic:~/h/public$ gmsh -3 sphere.step 
  Info    : Running 'gmsh -3 sphere.step'
  Info    : Started on Thu Mar 24 13:50:40 2011
  Info    : Reading 'sphere.step'
        ...    Step File Reading : sphere.step
        ...    STEP File   Read    ... 
  Elapsed time: 0 Hours   0 Minutes   0.000288 Seconds 
  CPU user time: 0 seconds 
  CPU system time: 0 seconds 
        ... Step File loaded  ... 
  Elapsed time: 0 Hours   0 Minutes   0.000393 Seconds 
  CPU user time: 0 seconds 
  CPU system time: 0 seconds 
     63 records (entities,sub-lists,scopes), 137 parameters
  
        ... Parameters prepared ... Elapsed time: 0 Hours   0 Minutes   0.00061 Seconds 
  CPU user time: 0 seconds 
  CPU system time: 0 seconds 
        ...   Objets analysed  ... 
  Elapsed time: 0 Hours   0 Minutes   0.001023 Seconds 
  CPU user time: 0.01 seconds 
  CPU system time: 0 seconds 
    STEP Loading done : 32 Entities
  Info    : Healing geometry (tolerance=1e-06)
  Info    : - fixing small edges
  Info    : removing degenerated edge 0
  Info    : removing degenerated edge 0
  Info    : - fixing spot and strip faces
  Info    : OCC Region 1 with 0 faces
  Info    : Read 'sphere.step'
  Info    : Meshing 1D...
  Info    : Mesh 1D complete (0 s)
  Info    : Meshing 2D...
  Info    : Mesh 2D complete (0 s)
  Info    : Meshing 3D...
  Info    : Meshing volume 1 (Frontal)
  Info    : CalcLocalH: 0 Points 0 Elements 0 Surface Elements 
  Info    : Check subdomain 1 / 1 
  Info    : 0 open elements 
  Info    : Meshing subdomain 1 of 1 
  Info    : 0 open elements 
  Info    : Mesh 3D complete (0 s)
  Info    : 0 vertices 0 elements
  Info    : Writing 'sphere.msh'
  Info    : Wrote 'sphere.msh'
  Info    : Stopped on Thu Mar 24 13:50:40 2011

and the resulting .msh file has no tetrahedrons:

  http://www.kuleuven-kortrijk.be/~bartv/sphere.msh

In the gmsh GUI, I already tried unselecting

  * Remove small edges in OpenCascade models
  * Remove small faces in OpenCascade models

before merging/importing the .step file, but this didn't help either.

What am I doing wrong here?  How can I draw a sphere in Salome and mesh
its volume using tetrahedrons with gmsh?

I am using gmsh 2.4.2 and Salome 5.1.5 on Ubuntu Maverick 10.10.

Regards,
Bart

-- 
	"Share what you know.  Learn what you don't."