dolfin team mailing list archive

[Anders Logg <logg@xxxxxxxxx>]

On Thu, Feb 28, 2008 at 03:08:25PM +0100, Johan Hake wrote:
> Dear all!
> 
> I hearby present version 0.1 of TriTetMesh. It is a c++/python wrapper of the 
> high quality mesh generators: Tetgen and Triangle.
> 
> The output format is dolfin mesh, and dolfin meshfunctions for markers. It is 
> also possible to output the native Tetgen and Triangle formats.
> 
> For now the code resides in a tarball:
> 
> <http://folk.uio.no/hake/tritetmesh/tritetmesh.tar.gz>
> 
> I have not checked if it builds on mac, but it should build on Linux/Ubuntu. 
> You will then need swig, python, python-dev, python-numpy, python-numpy-dev 
> and scons. (I think this is all...)
> 
> The documentation is sparse but have a look at the provided demos. It can be 
> usefull to look at the docstrings for the python functions too. As TriTetMesh 
> is a more or less complete wrapper of Triangle and Tetgen it is instructive 
> to have a look at their webpages for clues.
> 
> Tetgen <http://tetgen.berlios.de>
> Triangle <http://www.cs.cmu.edu/~quake/triangle.html>
> 
> Please have a try!
> 
> Send me an email if you encounter problems. Such discussions should probably 
> stay of this list ;)
> 
> Cheers 
> 
> Johan

Looks very nice!

I've also looked a bit a Netgen as an alternative to Tetgen and it
seems to have a simple interface that might be simpler to wrap than
Tetgen. Netgen can also save directly to DOLFIN XML (patch from
Kent-Andre that is in Netgen CVS).

Netgen uses input files like these:

# a cube
solid cube = plane (0, 0, 0; 0, 0, -1)
         and plane (0, 0, 0; 0, -1, 0)
         and plane (0, 0, 0; -1, 0, 0)
         and plane (1, 1, 1; 0, 0, 1)
         and plane (1, 1, 1; 0, 1, 0)
         and plane (1, 1, 1; 1, 0, 0);

# two shperes
solid sph1 = sphere (0.5, 0.5, 0.5; 0.58);
solid sph2 = sphere (0.5, 0.5, 0.5; 0.75);

# cut cube with inner and outer sphere
solid main = cube and sph2 and not sph1;

This would be *very* easy to wrap in DOLFIN so one could do things
like

  s1 = Sphere(...)
  s2 = Sphere(...)
  c  = Cube(...)
  
  mesh = Mesh(c + s2 - s1)

Perhaps this could be done also with Tetgen/Triangle?

-- 
Anders