CGAL users discussion list

["Sebastien Loriot (GeometryFactory)" <>]

Could you provide a minimal example showing the pb so that I can try to 
reproduce the issue?

Also what is your platform and your compiler?

Sebastien.


On 11/29/2013 04:09 PM, mytien wrote:
> Hello again,
> today I tried the 5.1 and 5.3 examples of the 3D Alpha Shape documentation:
> http://doc.cgal.org/latest/Alpha_shapes_3/index.html.
>
> They worked fine for me. But when I use alpha shapes in my program, it
> crashes as soon as execution reaches alpha shape code. Here is my relevant
> code:
>
> typedef CGAL::Exact_predicates_inexact_constructions_kernel Gt;
> typedef CGAL::Alpha_shape_vertex_base_3<Gt>          Vb;
> typedef CGAL::Alpha_shape_cell_base_3<Gt>            Fb;
> typedef CGAL::Triangulation_data_structure_3<Vb,Fb>  Tds;
> typedef CGAL::Delaunay_triangulation_3<Gt,Tds>       Triangulation_3;
> typedef CGAL::Alpha_shape_3<Triangulation_3>         AlphaShape;
> typedef Gt::Point_3                                  CGAL_Point;
> typedef AlphaShape::Facet                            CGAL_Facet;
> typedef AlphaShape::Cell_handle                      Cell_handle;
> typedef AlphaShape::Triangle                         CGAL_Triangle;
> typedef AlphaShape::Alpha_iterator                   Alpha_iterator;
>
> [...]
>
>
>      std::vector<floatCoordinate> pointCloud = pointCloudAsVector();
>      std::vector<CGAL_Point> points;
>      std::vector<floatCoordinate>::iterator piter;
>
>      for(piter = pointCloud.begin(); piter != pointCloud.end(); ++piter) {
>          CGAL_Point p = CGAL_Point(piter->x, piter->y, piter->z);
>          points.push_back(p);
>      }
>      AlphaShape as(points.begin(), points.end());
>      if(as.is_valid() == false) {
>          return false;
>      }
>      Alpha_iterator opt = as.find_optimal_alpha(1);
>      as.set_alpha(*opt); // CRASH
>
>
> Also, if I omit the part of finding the optimal alpha and simply go on to
> retrieving facets, it crashes too:
>
>      std::vector<CGAL_Facet> facets;
>      as.get_alpha_shape_facets(std::back_inserter(facets),
> AlphaShape::SINGULAR); // CRASH
>
> I know that my pointCloud and the conversion to CGAL points works, because I
> can create 3D delaunay triangulations with them. Can you help me to fix this
> problem?
>
> kind regards
> My-Tien
>
>
>
>
> --
> View this message in context: 
> http://cgal-discuss.949826.n4.nabble.com/3D-Alpha-Shape-crash-tp4658493.html
> Sent from the cgal-discuss mailing list archive at Nabble.com.