CGAL users discussion list

[Laurent Rineau <>]

On Tuesday 22 May 2007 08:52:28 

 wrote:
> Dear all,
>
> I am very New to CGAL.
> Now I have two questions on the 3D surface mesher in Chapter 30 of
> CGAL user and reference manual.
>
> 1) How can we get information to create the same figure in the section 3 of
> the chapter 30? I can get the vertex information like
>   
> ---------------------------------------------------------------------------
>---- Tr::Finite_vertices_iterator it;
>    for(it = tr.finite_vertices_begin(); it != tr.finite_vertices_end();
> ++it) fout << *it << std::endl;
>   
> ---------------------------------------------------------------------------
>---- But I don't know how to extract information on the triangulation patch
> connectivity.

All the surfacic information are in the object c2t3. See the documentation, 
for that class: 
http://www.cgal.org/Manual/3.2/doc_html/cgal_manual/Surface_mesher_ref/Concept_SurfaceMeshComplex_2InTriangulation_3.html

> 2) Can we use our own points on a surface instead of an implicit surface in
> the same example?

CGAL::Surface_mesher is for surface for which one do not have points. It is 
an 
alternative to the "marshing cube". However You can add several points before 
starting the surface mesh generator.

If you want to recreate a surface from a set of points, you need a surface 
reconstruction algorithm. As far as I know, the only one that is publicly 
available in CGAL is the alpha shape.

-- 
Laurent Rineau
INRIA - Sophia Antipolis
BP 93, 2004 Route des Lucioles
06902 Sophia Antipolis Cedex FRANCE