[Gmsh] Unstructured hexahedra mesh from STL geometry

Meiner Auchmeiner auchmeiner at googlemail.com
Tue Nov 23 20:02:55 CET 2010

Hello again,

thank you very much for your quick reply.

2010/11/23 Jean-Francois Remacle <jean-francois.remacle at uclouvain.be>:
> Le 23-nov.-10 à 17:25, Meiner Auchmeiner a écrit :
> Hi gmsh group,
> Hello,
> I was wondering if anybody here succeeded to mesh a STL geometry with
> an unstructured mesh consisting of hexahedra elements. I'm trying to
> mesh following file(s) using standard settings, except for the
> subdivision algorithm "All hexas": 500.stl & 500.geo (see attachment).
> I'm always getting the error messages "Error: Cannot evaluate point on
> discrete face" and "Error: Cannot compute parametric coordinates on
> discrete face".  Whereas meshing the STL geometry with tetrahedron
> elements work like a charm. Is there any intermediate step necessary
> to optimize (maybe with e.g. MeshLab) the input STL geometry? Or is
> there any gmsh preprocessing option/conversion I overlooked ?
> There is actually NO automatic hexaedral mesher in GMSH.
> For doing a better STL, you can use the reparametrization tools, see
> https://geuz.org/trac/gmsh/wiki/STLRemeshing (username wiki, password wiki).
> JF

Hmm, so do I get you right, there is no way (yet?) of generating
hexahedral meshes out of STL files in gmsh? In all my naivety I
thought it would be possible in GMSH to subdivide tetrahedra elements
in hexahedra elements... Say, what about the manual hexahedral mesher
in GMSH you just mentioned, is it - with the right manually input -
capable of meshing closed STL surface geometries with hexas?


> Thanks
> Uwe
> P.S.: The skeleton data have been obtained by courtesy of S. Van Sint
> Jan, Laboratory of Anatomy, Biomechanics and Organogenesis, Université
> Libre de Bruxelles.
> <500.stl><500.geo>_______________________________________________
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> Prof. Jean-Francois Remacle
> Universite catholique de Louvain (UCL)
> Ecole Polytechnique de Louvain (EPL) - Louvain School of Engineering
> Institute of Mechanics, Materials and Civil Engineering (iMMC)
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