CGAL users discussion list

["Laurent Rineau (GeometryFactory)" <>]

Le jeudi 09 février 2012 11:03:38 Dominik Szczerba a écrit :
> Hi,
> 
> I am generating a tet mesh directly from a segmented medical image
> more or less like
> 
> C3t3 c3t3 = CGAL::make_mesh_3<C3t3>(domain, criteria);
> const Tr& tr = c3t3.triangulation();
> 
> I am then converting it to another required representation more or less
> like:
> 
>    for( Finite_vertices_iterator vit = tr.finite_vertices_begin();
>    vit != tr.finite_vertices_end();
>    ++vit)
>    {
> // get vertices
>    }
> 
>    for( Cell_iterator cit = c3t3.cells_begin() ;
>    cit != c3t3.cells_end() ;
>    ++cit )
>    {
> // get cells
>    }
> 
> Now my question is: is there also cell connectivity (which cell has
> which neighbours) available in c3t3 after the mesh has been created?
> By "available" I mean that this information be already available for
> quick extraction, I do NOT mean its dedicated (lengthy) computation
> afterwards.

Sure.

c3t3.triangulation() is a full CGAL triangulation.

Given a Cell_handle, or any cell iterator, let's call it 'ci', you can call:

   ci->neighbor(i) // for i in {0, 1, 2, 3}

See the documentation of the Cell type here:

  
http://www.cgal.org/Manual/latest/doc_html/cgal_manual/TriangulationDS_3_ref/Concept_TriangulationDSCellBase_3.html

Here is the corresponding short link:

  http://bit.ly/wGwmY3

-- 
Laurent Rineau, PhD
R&D Engineer at GeometryFactory           http://www.geometryfactory.com/
Release Manager of the CGAL Project       http://www.cgal.org/