CGAL users discussion list

[Fernando Cacciola <>]

Hi Rob,

> error: ‘class
> CGAL::Surface_mesh_simplification::Edge_profile<CGAL::Polyhedron_3<CGAL::Simple_cartesian<double>,
> m3_items, CGAL::HalfedgeDS_default, std::allocator<int> > >’ has no
> member named ‘v0v1’

That's mistake in the documentation :( sorry about that.

The member is named: "v0_v1()"

You can see the actual class in the header:

$CGAL_DIR
 /include
  /CGAL
   /Surface_mesh_simplification
    /Policies
     /Edge_collapse
      /Edge_profile.h


Also, in the header:

$CGAL_DIR
 /include
  /CGAL
   /Surface_mesh_simplification
     /halfedge_collapse_Polyhedron_3.h

there is the function:

vertex_descriptor halfedge_collapse( edge_descriptor const& pq
                                   , Polyhedron_3<Gt,I,HDS,A>& aSurface
                                   ) ;

which you can just call to "replay" the decimation steps in the forward 
direction.

What is missing though is the reverse operation, which you will have to 
implement yourself. To do that, take close look at the implementation of 
halfedge_collapse() because the actual euler operation used depends on 
the local topology of the mesh around the collapsing edge.


HTH

Fernando Cacciola
www.geometryfactory.com