CGAL users discussion list

["Laurent Rineau (CGAL/GeometryFactory)" <>]

Le Wednesday 11 December 2013 06:45:09 Marek a écrit :
> I'm afraid this end's up with NULL pointer read excetion:
> "First-chance exception at 0x08061eba (mobjcg.dll) in robot.EXE: 0xC0000005:
> Access violation reading location 0x0000000000000000."
> 
> while trying to do:
> operator*()  Line 844 of compact container.h
> 
> as it tries to walk along edge:
> CGAL::internal::CC_iterator
> walk_along_edge
> ??$check_and_fix_vertex_along_edge
>  ?? :: ?? ::check_and_repopulate_edges()
> ?refine_balls@?$Protect_edges_sizing_field
> init_c3t3_with_features
> 
> 
> I can see  that it tries to traverse from not initialized point to one of
> which I've added as degenerated 1-D feature.
> 
> Do you have any further advise about how to fix this?

You can dig into the internal implementation of CGAL::make_mesh_3, in order 
to 
add extra 0d features to your mesh. If you also have 1d features, that should 
look like:

  C3t3 c3t3;
  CGAL::internal::Mesh_3::init_c3t3_with_features(c3t3,domain,criteria);

  // Here add a loop to add extra vertices (1d-features) to the triangulation.
  // Be careful to call c3t3.add_to_complex(vh,1) for each new vertex

  CGAL::refine_mesh_3<C3t3>(c3t3, domain, criteria /* extra parameters */);


You need to call "c3t3.add_to_complex(vh, 1)" for each vertex handle vh of 
new 
vertices you want to add as 1d-feature. The "1" here is the Corner_index 
parameter. It should be different for each "corner" (aka 1d-feature), but I 
know that the code of Mesh_3 never read those corner indices, for the moment 
(that may change in future versions).

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