CGAL users discussion list

[Peter Schröder <>]

What's the best way to remove a facet from a polyhedron_3? In my case I 
actually have a simplicial 2-manifold with boundary (arbitrary genus) if 
that makes a difference. I don't want to punch a hole. what I want is to 
"coalesce" the three boundary vertices of a given triangle into a single 
vertex (this will additionally remove [at least?] 3 other triangles; the 
"flaps") and consolidate all the surrounding edges correctly.

Basically I have need for a mesh cleanup operation in which I remove all 
zero area triangles without changing the genus of the surface (and, yes, 
the zero area triangle could be on the boundary, but the generic case is 
for it to be someplace in the interior of the mesh).

I looked at some of the operations for polyhedron_3, but none appears to 
be a direct match. One possibility is to do two consecutive edge 
contractions. Is that the preferred way to go about this, given the 
primitives available?

peter