[Gmsh] Identifiers of entities generated by extrusion

[Lucas Blattner Martinho]

Dear Gmsh developers and users,



I am using Gmsh to build the geometric model of an oil pipeline subjected to
the electromagnetic interference from a nearby high voltage transmission
line.

After making an extrusion to build a surface corresponding to a quarter of
the pipe cross-section with the command

*Pipeline_Quarter_Section1[] = Extrude{ {1,0,0},
{0,Pipe_Center_Y,Pipe_Center_Z}, Pi/2}
{Line{Pipe_Inner_Radius_Line1,Pipe_Thickness_Line1,Coating_Thickness_Line1};
Layers{Circunference_Discretization}; Recombine;};
*

I would like use the indentifiers of the entities generated by this
extrusion (the surface and a few lines) that became stored in the list
Pipeline_Quarter_Section1[] in further geometric transformations.
However, the only way I could find to tell for example that
Pipeline_Quarter_Section1[3] stores the identifier of a particular line (and
not of a different one generated by the same extrusion transformation) was
trial and error...

Is it possible to predict the pattern of these vectors of entities generated
by Gmsh in such transformations? I have found a few hints at the mesh
tutorial t3.geo (http://www.geuz.org/gmsh/doc/texinfo/gmsh-full.html#SEC65),
but it does not seem to cover all possible cases...

Would it also be possible to generate through the extrusion separated lists
of entities that do not mix lines, surfaces and volumes in an unpredictable
sequence?



Yours faithfully,

Lucas Blattner Martinho


Laboratório de Eletromagnetismo Aplicado  - LMAG
Escola Politécnica da Universidade de São Paulo
São Paulo,  Brasil
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