CGAL users discussion list

[Qianqian Fang <>]

On 03/18/2011 04:09 AM, Sebastien Loriot (GeometryFactory) wrote:
> Christoph Weber wrote:
> > Hi,
> >
> > I'm working a similar subject. If you are just looking for a tool, I
> > would emphasize TetGen. It is open source, dokumented and focused on
> > FE-Meshes. 
> By curiosity, why do you prefer using TetGen than CGAL's Mesh_3 to
> generate FE-Meshes?

I've been using both CGAL and tetgen in my research and I noticed
that CGAL 3D polyhedral mesher is very unstable for most of my inputs.

Here is a simple example, the input mesh is a triangular surface
mesh extracted from a binary CT image of a rat head. The OFF format
and POLY format files can be accessed from

http://nmr.mgh.harvard.edu/~fangq/temp/post_extract.off
http://nmr.mgh.harvard.edu/~fangq/temp/post_vmesh.poly

both files contain the same mesh. Using the .poly file with
tetgen, I can get a nice 3D tetrahedral mesh, but with the
CGAL polyhedral mesher (examples/Mesh_3), the program aborted
when processing the OFF file. This behavior can be reproduced
from CGAL 3.5 to the latest 3.8 beta. The polyhedral mesher
failed for almost all tested surface meshes except those shipped
with CGAL. Not sure what had caused the problem.

The robustness of CGAL 3D image mesher is better, but there is
one issue that keeps it from perfect for general-purpose use.
I summarized it in this post

https://lists-sop.inria.fr/sympa/arc/cgal-discuss/2011-03/msg00067.html

it would be great if someone can comment on this.

Qianqian


> The Polyhedron demo has a plugin that allows to generate 3D meshes from
> an off file (Operations->Create a tetrahedral mesh).
>
> S.
>
> > regs, Christoph
> > Am Donnerstag, den 17.03.2011, 12:53 -0500 schrieb Fabio Casado Ruiz:
> > > Hi. I'm studying several tools and libraries for mesh generation to 
> > > use in Finite element Analysis. Has anyone used CGAL for this 
> > > purposes or has any knowledge where to read about its pros and cons 
> > > for this purpose???
> > > Thanks a lot..
> > > F.