CGAL users discussion list

[Song Lin <>]

Thank you very much!

Lin

在 2010-04-27二的 08:14 +0200，Sebastien Loriot (GeometryFactory)写道：
> Song Lin wrote:
> > Hi,
> > 
> > I want to check if the edge between two adjacent vertices belongs to
> > Alpha_shape_3:(to decide if the two vertices are in one group)
> > 
> > vector<Vertex_handle> adjacent_vertices;
> > as.finite_adjacent_vertices(vit,back_inserter(adjacent_vertices));
> > for (int i=0;i<adjacent_vertices.size();i++)
> > {
> >     if(as.classify(###the edge between vit and
> > adjacent_vertices[i]###,0)==Alpha_shape_3::EXTERIOR)
> >     {
> >             
> >     }
> > }
> > 
> > But I found that an edge was defined as:
> > typedef Triple<Cell_handle, int, int> Edge;
> > 
> > Can I build an edge without the information of Cell_handle? If can't,
> > what should I do to build an edge that can be used in the function
> > "as.classify()"?
> > 
> > Best regards,
> > Lin
> Hello,
> 
>  From the manual, you can see that the class Alpha_shape_3 inherits
> from its template triangulation. All triangulation in CGAL inherits from
> the class Triangulation_3.
>  From here:
> http://www.cgal.org/Manual/last/doc_html/cgal_manual/Triangulation_3_ref/Class_Triangulation_3.html#Function_bool_is_edge6Vertex_handle_u+_Vertex_handle_v+_Cell_handle___c+_int___i+_int___j9_const;
> you will find the function is_edge that will give you
> the information needed to define the triple.
> 
> S.
> 
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