CGAL users discussion list

["Sebastien Loriot (GeometryFactory)" <>]

Do you know how to display a set of edges in OpenGL?
If no you should ask your favorite internet search engine for a solution
(there are a lot of tutorials about that)

To extract points from edges in CGAL, you can do something like that:

for( typename Triangulation_3<GT, TDS>::Finite_edges_iterator
     eit = T.finite_edges_begin(); eit != T.finite_edges_end(); ++eit)
{
  GT::Point_3 pt1=eit->first->vertex(eit->second)->point();
  GT::Point_3 pt2=eit->first->vertex(eit->third)->point();
}

See here for the definition of edges and Facets in 3D triangulations.
http://www.cgal.org/Manual/latest/doc_html/cgal_manual/TriangulationDS_3_ref/Concept_TriangulationDataStructure_3.html#Cross_link_anchor_1368

//this is the part you need to look at
typedef Triple<Cell_handle, int, int>
	Edge; 	(c,i,j) is the edge of cell c whose vertices indices are i and 
j. (See Section 39.1.)
typedef std::pair<Cell_handle, int>
	Facet; 	(c,i) is the facet of c opposite to the vertex of index i. (See 
Section 39.1.)
//


Sebastien.

On 02/10/2012 11:50 AM, mysmax wrote:
> Hello check this snippet
>
>    // Finite edges indices.
>    for( typename Triangulation_3<GT, TDS>::Finite_edges_iterator
>           eit = T.finite_edges_begin(); eit != T.finite_edges_end(); ++eit) {
>        gv<<  2
>           <<  V[(*eit).first->vertex((*eit).second)]
>           <<  V[(*eit).first->vertex((*eit).third)]
>           <<  "\n"; // without color.
>        //<<  4<<  drand48()<<  drand48()<<  drand48()<<  1.0; // random
> color.
>    }
>
> how to render this output in opengl?.
>
> Advance thanks
> mysmax
>
> --
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> http://cgal-discuss.949826.n4.nabble.com/Triangulation-3-problem-tp4375897p4375897.html
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