CGAL users discussion list

["Sebastien Loriot (GeometryFactory)" <>]

Iterate over halfedges not vertices.

Sebastien.

On 12/16/2013 06:29 PM, Zohar wrote:
> To check the number of border edges incident to the vertex is a good idea,
> but isn't that exactly the problem of CGAL with non-manifold? Namely, the
> Halfedge_around_vertex_const_circulator doesn't iterate all the edges or
> detect border correctly. On the non-manifold vertex in my example above it
> counts only two border edges. For example, the following code doesn't work:
>
> bool is_manifold(Polyhedron_3 &mesh)
> {
>      // count border edges
>      for ( Vertex_const_iterator v = mesh.vertices_begin() ; v !=
> mesh.vertices_end() ; v++ ) {
>          Halfedge_around_vertex_const_circulator hc = v->vertex_begin();
>          Halfedge_around_vertex_const_circulator hc_end = hc;
>         int nBorderEdges = 0;
>          CGAL_For_all(hc, hc_end) {
>              if ( hc->is_border() ) {
>                 nBorderEdges++;
>                 if ( nBorderEdges > 2 )
>                         return false;
>              }
>          }
>      }
>
>      return true;
> }
>
>
>
>
> --
> View this message in context: 
> http://cgal-discuss.949826.n4.nabble.com/Undetected-non-manifold-vertex-in-poly3-tp4658551p4658562.html
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