CGAL users discussion list

[Camille Wormser <>]

> > Basically, this is a polyhedron with five vertices, (0,10,0), 
> > (0,0,0), (2,5,6),
> > (5,7,0) and (1,-1,-4). The simplest triangulation will contain just 
> > two tetrahedrons (excluding the cells that contain infinite 
> > vertices). However, I find that the result contains overlapping 
> > cells, for example, cell [1 0 3 4] overlaps with cell [2 1 3 4]. Is 
> > this common to the 3D triangulation feature of CGAL? Or did I 
> > misinterpret the result?

Note that 0 is the index of the infinite vertex, in the 9 lines which 
compose the list of tetrahedra. This means, from your output, that there 
are 3 tetrahedrons (the ones without 0, which share edge 2-4) and 6 
outer faces (the ones with 0). On the other hand, in the last 9 lines of 
the output, the numbers 0 to 8 represent the 9 tetrahedra that have been 
listed above:
for example, first line 5 1 6 2 refers to first tet 1 0 3 4 and means
the tet opposite to vertex 1 is tet 5
the tet opposite to vertex 0 is tet 1
the tet opposite to vertex 3 is tet 6
the tet opposite to vertex 4 is tet 2