[Gmsh] Gmesh

Geordie McBain gdmcbain at freeshell.org
Mon Jun 7 01:32:30 CEST 2010

2010/6/5 Christopher Russ <c.russ at uq.edu.au>:
> Gents,
> I have a question for you on gmesh.  Can it tetrahedral mesh an assembly (4
> parts) which is in .stl format. I would like it exported as an abaqus or
> ansys file.
> Regards
> Chris Russ
> Uni of Qld

Correct me if I'm wrong, but I don't think STL can represent multipart
assemblies, except as an undifferentiated triangulated surface; but if
that suffices, then yes, Gmsh should indeed be able to mesh the
enclosed volume with tetrahedra.  Or do you mean that each part is in
a separate STL file?  That should be O.K. too, but I haven't tried it.
 Post a simple example, if you like.

One thing to watch for is if the parts have coincident faces, edges,
or points.  STL only defines surfaces in terms of triangles, and these
in terms of their vertices, and these in turn in terms of their
coordinates, so the concept of adjacency is only represented by the
floating point equality of these coordinates, and floating point
comparisons are murky.  GTS <gts.sf.net> is a far nicer format for
triangulated surfaces, but it's some way from displacing the incumbent
de facto standard STL.

I'm not familiar with the list of formats abaqus or ansys can read these days.