CGAL users discussion list

[Burak ER <>]

Your solution seems to get all the facets either they are interface or 
a surface facets. How can I determine the surface facets? A zero
neighbor value indicates it as a surface facet?

Thank you in advance.

Sal, 2013-10-15 tarihinde 16:32 +0200 saatinde, Laurent Rineau
(CGAL/GeometryFactory) yazdı:
> Le lundi 14 octobre 2013 23:50:44 Burak ER a écrit :
> 
> > Dear Cgal mail list subscribers,
> 
> > 
> 
> > I am searching for a way to get interface facets between all the
> 
> > tetrahedras on a mesh. Therefore, every facet should have a self
> index
> 
> > and the tetrahedrons indices which it belongs to. For example;
> 
> > 
> 
> > struct facet{
> 
> > int id;
> 
> > int tetrahedron_id1;//first tetrahedron
> 
> > int tetrahedron_id2;//second tetrahedron
> 
> > }
> 
> > 
> 
> > What is the best(fastest) way to solve this problem with cgal 3d
> 
> > meshing?
> 
>  
> 
> You can use the template CGAL::Triangulation_cell_base_with_info_3 to
> add extra member fields to the cells of CGAL 3D triangulations.
> 
>  
> 
> For example:
> 
> struct Cell_info {
> 
> int id;
> 
> };
> 
>  
> 
> Then, on a 3D triangulation, use the facets iterators:
> 
>  
> 
> std::vector<facet> all_facets; // container of 'facet' struct
> 
> int facet_id = 0;
> 
>  
> 
> for(Tr::Finite_facets_iterator
> 
> fit = tr.finite_facets_begin(),
> 
> end = tr.finite_facets_end(); fit !=end; ++fit)
> 
> {
> 
> Tr::Cell_handle cell = fit->first;
> 
> int index = fit->second;
> 
>  
> 
> Tr::Cell_handle other_cell = cell->neighbor(index);
> 
>  
> 
> // Then here you can use cell->info().id and other_cell->info().id
> 
> // to fill your container of facets.
> 
> facet new_facet = { facet_id++, cell->info().id,
> other_cell->info().id };
> 
> all_facets.push_back(new_facet);
> 
> }
> 
>  
> 
> In my opinion, you should use 'std::size_t' instead of 'int' as "id
> type".
> 
>  
> 
> -- 
> 
> Laurent Rineau, PhD
> 
> R&D Engineer at GeometryFactory http://www.geometryfactory.com/
> 
> Release Manager of the CGAL Project http://www.cgal.org/
> 
>  
> 

-- 
Burak ER
Research Assistant
Faculty of Natural Sciences & Engineering
Bursa Technical University

mailto:
https://github.com/burak-er