CGAL users discussion list

Hi,
The TriangulationDataStructure_3 does not know whether cells are finite 
or infinite, it is not embedded in any geometric space, it is just a graph.
You can construct with it a graph that represents a triangulation 
(simplicial complex) of a 3d combinatorial sphere in R4. In particular, 
all cells must have 4 neighbors.
best
        Monique Teillaud

laurency franck wrote:
> Hi,
> i trying to construct a triangulation using
> the structure TriangulationDataStructure_3 and i have a
> question about shipboard cells:
> i have to put 4 neighbors at these cells but they have only
> 3 neighbors. I have trying to put the NULL value for the 4th
> neighbor but after if i done a ".is_valid" on my structure
> it print me errors. So i have tried to put the cell itself as 4th
> neighbor and it is also not valid and it print me:
> "sum of the indices != 6 "
> I have also read that there is infinite cell but i don't know how
> to create a such cell.
> So if somebody have an idea on what i have to put as 4th
> neighbor it will be cool!
>  
> thanks for your answers
> Ih
>
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