CGAL users discussion list

[Stephane Tayeb <>]

Lehtonen, Matti/HIIT wrote:
> Hi!
>
> I am using the code from chapter "47.3.2   Mesh Generation From a Polyhedral
> Domain", the elephant case to generate different meshes from [classified] 
> point
> cloud.
>
> The problem that I am currently facing is some type mismatch for tetrahedron
> struct K: public CGAL::Exact_predicates_inexact_constructions_kernel {};
> typedef CGAL::Mesh_3::Robust_intersection_traits_3<K> Geom_traits;
> typedef CGAL::Polyhedron_3<Geom_traits> Polyhedron;
> typedef Polyhedron::Point_3 Point;
> typedef Polyhedron::HalfedgeDS HalfedgeDS;
> typedef CGAL::Polyhedral_mesh_domain_3<Polyhedron, Geom_traits> Mesh_domain;
> typedef CGAL::Mesh_triangulation_3<Mesh_domain>::type Tr;
> typedef CGAL::Mesh_complex_3_in_triangulation_3<Tr> C3t3;
>
> {
>         std::ofstream                   vrml_file( "mesh-1-out.wrl" );
>         CGAL::VRML_2_ostream    vrml_stream( vrml_file );
>
>         for( C3t3::Facet_iterator f = c3t3.facets_begin();
>                  f != c3t3.facets_end(); ++f )
>         {
>                 C3t3::Triangulation::Triangle   t = 
> c3t3.triangulation().triangle( *f );
>
>                 vrml_stream << t;
>         }
>
>         for( C3t3::Cell_iterator c = c3t3.cells_begin();
>                          c != c3t3.cells_end(); ++c )
>         {
> // This line won't compile...
>                 C3t3::Triangulation::Tetrahedron                t =
> c3t3.triangulation().tetrahedron( *c );
> // This compiles & links
>                 ///C3t3::Triangulation::Tetrahedron     t;
>
>                 vrml_stream << t;
>         }
>
>         vrml_stream.close();
> }
>
> Everything seems to be okay, but for some reason I got following error (see 
> end
> of mail), which looks like that tetrahedron other than
> C3t3::Triangulation::Tetrahedron is returned. The triangle part works fine, so
> what I am doing wrong?
>
> CGAL version is 3.5.1-1 (Ubuntu 10.04) and GCC is 4.4.3-4ubuntu5.
>
> Lehtonen, Matti
>
> Researcher, head programmer - Helsinki Institute for Information Technology 
> HIIT
> http://www.hiit.fi/

Hi,

c3t3.triangulation().tetrahedron( *c ) calls tetrahedron() on a Cell and 
the documented function (3D Triangulation class) is:
Tetrahedron t.tetrahedron (Cell_handle c).

Calling c3t3.triangulation().tetrahedron( c ) may solve your issue 
(C3t3::Cell_iterator should be convertible to Cell_handle)

Regards,
Stéphane.

--
Stephane Tayeb
Software engineer - INRIA Sophia Antipolis
Geometrica Project-Team