CGAL users discussion list

[Monique Teillaud <>]

Nico Kruithof wrote:
> It is a pair of a cell_handle and an int:
>
> Cell_handle ch = it->first;
> int i = it->second;
>
> The facet is one of the faces of the Cell_handle (tetrahedron). More
> specifically, it doesn't contain the vertex with index i. So the
> Cell_handle contains four vertices and each vertex is associated with
> a point:
>
> ch->vertex(0)->point()
> ch->vertex(1)->point()
> ch->vertex(2)->point()
> ch->vertex(3)->point()
>
> and the face contains the points:
>
> ch->vertex((i+1)%4)->point()
> ch->vertex((i+2)%4)->point()
> ch->vertex((i+3)%4)->point()
>
> Hope this makes things clear.

not really, I am afraid... Nico, you missed a few chapters of the novel: 
Dennis is now using a 2d triangulation.




> On Sun, Nov 2, 2008 at 10:51 PM, Dennis Endt 
> <>
>  wrote:
> > Monique Teillaud schrieb:
> > > If you are lucky (= your points really don't belong to a plane
> > > parallel to any xy,xz,yz plane), you will get the same triangulation
> > > three times, which is not what you want (I guess so). Yhen using one
> > > of these random traits should give you what you want.
> > > If you are less lucky, one of the computationa will crash. Then, use
> > > one of the other two.
> > > I'm afraid that's the best you can do if you don't know anything about
> > > your data, except the fact that they are almost coplanar.
> > Hi Monique,
> >
> > how can avoid a crash? Is it enough to check for "is_valid()"?
> >
> > I read the manual and solved the problem with the edges and the points.
> >
> > But I don`t understand how I get the 3 Points of a face with the help
> > of  the following loop?
> >
> > for(Delaunay::Finite_faces_iterator it = T.finite_faces_begin(); it !=
> > T.finite_faces_end(); it++)
> > {
> > }
> >
> > I thought about:
> > (*it).vertex(1)->point()
> > (*it).vertex(2)->point()
> > (*it).vertex(3)->point()
> >
> > Is that right?
> >
> > Best,
> > Dennis
> > --
> > You are currently subscribed to cgal-discuss.
> > To unsubscribe or access the archives, go to
> > https://lists-sop.inria.fr/wws/info/cgal-discuss