CGAL users discussion list

[Olivier Devillers <>]

> Le 8 juil. 2019 à 09:23, BRYang 
> <>
>  a écrit :
> 
> Hi,
> I have got a question. For a delaunay triangulation, a facet is incidental 
> to two cells which share the facet, so a facet in delaunay triangulation 
> has 
> three vertices. 
> 
> However, it shows that in a regular triangulation Rt, we can access four
> vertices of a facet ffi as follows:
> ffi->first->vertex(i)->point(), where ffi is a Finite_facets_iterator and i
> \in {0,1,2,3}.
> 
> Does that mean that any three of the four vertices could generate 
> a face with the three vertices in regular triangulation? 
> 

A facet is a pair (cell, index)

The cell is one of the two cells incident to the facet,
The index tells you which vertex of the cell you have to ignore to get the 
facet.


(This is in the manual !)