CGAL users discussion list

["Sebastien Loriot (GeometryFactory)" <>]

If your nef polyhedron is simple you can export it to a Polyhedron_3
(facets will be automatically triangulated) and use that example:
http://www.cgal.org/Manual/latest/doc_html/cgal_manual/Envelope_3/Chapter_main.html#Subsection_35.3.1

To get the triangles you can use a boost::transform iterator over
the range P.facets_begin (),P.facets_end().

see also:
http://www.cgal.org/Manual/latest/doc_html/cgal_manual/Nef_3_ref/Class_Nef_polyhedron_3.html#Function_void_convert_to_polyhedron6Polyhedron__P9_const;

On 02/02/2012 10:28 PM, noel wrote:
> I have a 3D Nef polyhedron.  I want a 2D polygon representing the silhouette
> of that polyhedron (bird's eye view).  I've been looking at Envelopes but am
> unsure if that is the way to proceed.  Wouldn't it be easier just to glide
> it through the xy plane, intersect it there and then use that intersection
> to build my polygon?
>
> If envelopes are the correct way to do this, I find the three examples are a
> little too different to what I need to be of any real use.  Does anyone have
> a better example lying around the place?
>
> --
> View this message in context: 
> http://cgal-discuss.949826.n4.nabble.com/Slhouette-From-3d-to-2d-tp4352895p4352895.html
> Sent from the cgal-discuss mailing list archive at Nabble.com.