CGAL users discussion list

[Monique Teillaud <>]

Hi,

If you want your Triangilation_3 to pass the is_valid test, you must 
create infinite cells as well.
See the User manuel of 3D Triangulations, 1st section, Representation.

You can also simply triangulate the set of points formed by the vertices 
of the cube, using the insert() method, then the triangulation will be 
valid.

Shuchu Han wrote:
> Hi all,
>
> Can anyone give me some hint about this problem? Thanks a lot !
>
> Currently, I have a cube mesh, which means the elements are hexahedrons. 
>  I wanna tessellate the cube mesh to tetrahedron mesh and represent it 
> by CGAL::Triangulation_3 .  I understand the orientation of a 
> tetrahedron should be positive and the index relationship between 
> neighbor tets. However, still can not get valid Triangulation_3 after 
> try several indexing methods. Especially,  my test program failed at 
> counting the number of finite edges and visit the edges.
>   
>  *          
>  *   5----------8
>  *   |\         |\
>  *   | \        | \
>  *   |  \       |  \
>  *   |   6----------7
>  *   |   |      |   | 
>  *   1---------\4 | 
>  *    \  |       \  |
>  *     \ |        \ |
>  *      \|         \|
>  *       2----------3
>
>
> My tets:
>
> 4 5 2 7      // center one
> 6 2 5 7      // 6 opposite to 4
> 2 3 4 7      // 3 opposite to 5
> 4 7 8 5     // 8 opposite to 2
> 5 4 2 1     // 1 opposite to 7


--
Monique Teillaud
INRIA Sophia Antipolis - Méditerranée
http://www.inria.fr/sophia/members/Monique.Teillaud/