CGAL users discussion list

[Benjamin schwarz <>]

I am not a CGAL expert and have no time to dive in your code right now, sorry.

Anyway, I know CGAL polygons are restricted to the construction of
manifold surfaces, and suspect your problem is somehow connected to a
non-manifold case. Singular facets are not the only cases of
non-manifoldness in an alphashape :
Consider an alphashape made of two 3-simplices (Alpha_shape_3::Cell)
sharing a single vertex. The surface of this object is not manifold.

  hope this helps

    --Ben