[Gmsh] 3D meshing

[Christophe Geuzaine]

On 31 Aug 2011, at 14:13, Cristóbal Bertoglio B. wrote:

> Hi
> 
> I'm trying to construct a volumetric mesh from an already existing surface mesh.
> 
> In past tests I was using the Frontal algorithm (+ netgen
> optimization) since it gave me less nodes, no surface triangles and no
> tetrahedra with the 4 nodes on the external surface. However, when
> running it for this example gives several errors of type I indicate
> bellow.
> 
> In contrast,  Algorithm 1 works perfectly (however it produces more
> nodes, create surface triangles and give me tetrahedra with the 4
> nodes on the external surface, all things that I want to avoid).
> 
> Does some know the reason why Delaunay works and Frontal doesn't ?
> 

Hi Cristobal,

The frontal algorithm is definitely less robust than the Delaunay. Do you still get bad tets if you optimize your mesh ("Optimize" and/or "Optimize Netgen") in the mesh menu?



> The mesh is also attached.
> 
> Thanks in advance,
> 
> Cristobal.
> 
> -------------
> 
> Info    : Meshing volume 0 (Frontal)
> Info    : Region 0 Face 1, 3 intersect
> Info    : CalcLocalH: 13932 Points 0 Elements 27860 Surface Elements
> Info    : Check subdomain 1 / 1
> Info    : 27860 open elements
> Error   : ERROR: Edge 20 - 33 multiple times in surface mesh
> ......
> Error   : ERROR: Surface mesh not consistent
> Error   : ERROR: Stop meshing since surface mesh not consistent
> Info    : Mesh 3D complete (1.84027 s)
> Info    : 13932 vertices 27860 elements
> Error   : ------------------------------
> Error   : Mesh generation error summary
> Error   :     0 warnings
> Error   :   201 errors
> Error   : Check the full log for details
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-- 
Prof. Christophe Geuzaine
University of Liege, Electrical Engineering and Computer Science 
http://www.montefiore.ulg.ac.be/~geuzaine