CGAL users discussion list

[David Coeurjolly <>]

Dear all,

I've to admit that I'm a brand new CGAL user for a couple of weeks and
my questions may be stupid. My problem is quite simple: cut a polyhedron
with an oriented plane.

It is quite easy to tag  the vertices ('exterior/interior') and to
create the new halfedges/vertices for intersection points (edge/plane).
But I have troubles to "remove" the exterior vertices.

More precisely, I've pushed in a list<Halfedge_handle>, an halfedge
handle per exterior vertex (called list_exterior_handles) obtained
during the exterior vertex scan step. My idea was to use P.erase_facet()
as follows:

Halfedge_around_vertex_circulator circ;
for( list<Halfedge_handle>::iterator v = list_exterior_handles.begin();
v != list_exterior_handles.end() ; ++v){
        
        circ = (*v)->vertex_begin();
        unsigned int deg = (*v)->vertex()->degree();
        for (unsigned int i=0; i< deg; i++)
          if (not circ->is_border()) P.erase_facet(circ);
        circ++;
}       

But this does not work..... I obtain segfaults due to the dereferencing
 of a NULL pointer in the (*v)->vertex()->degree() computation.

Do you have any idea of what's going on ? By the way, my choice of the
erase_facet operation may not be not good.. Any other suggestion ?

Thanks in advance, regards,
david


-- 
----------------
David Coeurjolly - Chargé de recherche CNRS
Laboratoire LIRIS-UMR 5205
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