CGAL users discussion list

[Bart Janssens <>]

Hello all,

I am currently trying to implement boolean operations in the K-3D 3D modeler 
(http://www.k-3d.org) by making use of the CGAL library.

The method I initially intended to use was to convert from K-3D to CGAL 
Polyhedra, then convert to Nef Polyhedra, apply the boolean operation, 
convert back to CGAL Polyhedra using convert_to_Polyhedron and then finally 
convert back to the K-3D format.

Unfortunately, the convert_to_Polyhedron method only converts the N2-N1 test 
case as seen on http://www.k-3d.org/wiki/CGAL_Boolean_Operations

This leaves me with the following questions:
        - Is there an easy way to eliminate the hole seen in the N1-N2 
test-case that 
I have missed in the documentation?
        - Is there an example on how to iterate over the Nef_polyhedron_3 
components 
to directly convert them to another format? The K-3D format supports holes, 
so it might be possible to convert without eliminating the holes. The 
iteration I use to convert from Polyhedron_3 to K-3D looks like this:

------------------------------------------------------------------------------------------------------------------
for (Polyhedron::Facet_const_iterator f = Polyhedron.facets_begin(); f != 
Polyhedron.facets_end(); ++f)
{
        Polyhedron::Facet::Halfedge_around_facet_const_circulator facet_start 
= 
                f->facet_begin();
        Polyhedron::Facet::Halfedge_around_facet_const_circulator 
edge_circulator =
                 facet_start;
        do
        {
                const Polyhedron::Halfedge& halfedge = *edge_circulator;
                // K-3D stuff
                ++edge_circulator;
        } while (facet_start != edge_circulator); 
}
------------------------------------------------------------------------------------------------------------------

I was wondering if it is possible to do something similar (though more 
complicated, probably :) using a Nef Polyhedron.

Kind regards,

-- 
Bart Janssens