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["Sebastien Loriot (GeometryFactory)" <>]

On 03/09/2012 03:33 PM, freckles wrote:
> I'm doing lots of join vertex operations, basically to perform halfedge
> collapses, and I ran into a problem while I was traversing the star of a
> vertex "u". When I try to access the ID [vertex_handle->id()] or point
> [vertex_handle->point()], of one of the vertices which the vertex "u" points
> to, my program dies. I'm actually thinking that this is because the topology
> becomes invalid or non-2 manifold after a certain collapse.
>
> Is there a way to check if a vertex in a polyhedron is valid, given that I
> have the halfedge pointing to it, and the halfedge is valid?
>
> Actually, is it possible for a valid halfedge to point to an invalid
> halfedge?
>
> Thanks a lot.
How do you perform the collapse of edge? If you do it by hand, it might
be that the polyhedron get invalid due to a bad operation.

You can use the is_valid()
bool    P.is_valid ( bool verbose = false, int level = 0) const
documented here:
http://www.cgal.org/Manual/latest/doc_html/cgal_manual/Polyhedron_ref/Class_Polyhedron_3.html

to debug this, after each collapse.

Sebastien.

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