[Gmsh] Unstructured hexahedra mesh from STL geometry

Jean-Francois Remacle Jean-Francois.Remacle at uclouvain.be
Wed Nov 24 20:33:29 CET 2010


Le 24-nov.-10 à 20:11, Meiner Auchmeiner a écrit :

> I just wanted to drop you all a quick note that I finally found a
> solution for generating hexahedra meshes out of STL surfaces (with an
> intermediate tetrahedral mesh step). Unfortunately, this solution is
> not GMSH but an external program :(. As a further drawback this tool
> is not even OpenSource... Fortunately, the academic license of it is
> quite affordable. So everybody who runs into the same problems I did
> should take a look at CUBIT (from Sandia National Labs). I hope it's
> ok that I point towards this external solution - please excuse any
> inconvenience caused.
>

no problemo

JFR

> Cheers,
> Uwe
>
> ---
>
> 2010/11/23 Meiner Auchmeiner <auchmeiner at googlemail.com>:
>> 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?
>>
>> Uwe
>>
>>
>>
>>> 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>_______________________________________________
>>> gmsh mailing list
>>> gmsh at geuz.org
>>> http://www.geuz.org/mailman/listinfo/gmsh
>>>
>>> ------------------------------------------------------------------
>>> 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)
>>> Center for Systems Engineering and Applied Mechanics (CESAME)
>>> Tel : +32-10-472352 -- Mobile : +32-473-909930
>>>
>>>
>>>
>>>
>>>
>>>
>>

------------------------------------------------------------------
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)
Center for Systems Engineering and Applied Mechanics (CESAME)
Tel : +32-10-472352 -- Mobile : +32-473-909930







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