CGAL users discussion list

["Sebastien Loriot (GeometryFactory)" <>]

Fulvio Mastrogiovanni wrote:
> Dear All,
>
> I am playing with the surface parameterization facilities offered by 
> CGAL. When representing a Polyhedron_3 as a 2D surface, I need to 
> extract the border of the 2D UV mapping in terms of vertex coordinates. 
> I guess I must go through the halfedge related structures, but it is not 
> clear to me how to do it.
>
> Any suggestion?
>
> Thanks a lot.
>
> Fulvio
To get halfedges that are on the boundary of a polyhedron,
you must first call function normalize_border() and
then you can use the range [border_halfedges_begin(),halfedges_end() )
to iterate over border halfedges.
To get the incident vertex of a halfedge use vertex() member function
which gives you a handle. Coordinates of the corresponding point can be
retrieved using the member point() function.

See details here:
http://www.cgal.org/Manual/beta/doc_html/cgal_manual/Polyhedron_ref/Class_Polyhedron_3.html


S.