CGAL users discussion list

[Zohar <>]

1.
WeiHua solved it. CGAL is missing a precondition that checks that the target
flipped edge doesn't already exist. For example, flipping one of a tet
edges. So the following check is needed:

bool does_flip_exist(Halfedge_handle he)
{
        Vertex_handle v1 = he->next()->vertex();
        Vertex_handle v2 = he->opposite()->next()->vertex();
    Halfedge_around_vertex_circulator hc = v1->vertex_begin(), hc_end = hc;
        CGAL_For_all(hc, hc_end) {
                if ( hc->opposite()->vertex() == v2 )
                        return true;
        }
        return false;
}

2.
It would be useful to an option to check also the geometry after the flip
(for intersections), similar to the test in the simplification package.



--
View this message in context: 
http://cgal-discuss.949826.n4.nabble.com/Polyhedron-flip-edge-crash-tp4659723p4659724.html
Sent from the cgal-discuss mailing list archive at Nabble.com.