CGAL users discussion list

["Grimm, Raphael (IAR)" <>]

Hello,

I have a non-convex mesh and want to check whether a point is within a certain distance of it. Since distance queries are slow, I decided to inflate the mesh and check whether the point is inside.

Scaling does not work, since my mesh is concave.

I did some looking around and came across minkowski_sum_3. I am planning to use a sphere to inflate my original mesh by using minkowski_sum_3.

I wrote some simple test for minkowski_sum_3 that adds a tetrahedron to a cube (code is attached).

This test crashes with a segfault. Here is the stack trace:

1  CGAL::SNC_FM_decorator<CGAL::SNC_structure<CGAL::Epick, CGAL::SNC_indexed_items, bool>>::determine_facet                                                          stl_vector.h                           805  0x55555559244a

2  CGAL::SNC_FM_decorator<CGAL::SNC_structure<CGAL::Epick, CGAL::SNC_indexed_items, bool>>::create_facet_objects                                                     In_place_list.h                        84   0x5555555a0dea

3  CGAL::SNC_external_structure<CGAL::SNC_indexed_items, CGAL::SNC_structure<CGAL::Epick, CGAL::SNC_indexed_items, bool>>::categorize_facet_cycles_and_create_facets stl_list.h                             953  0x5555555a16d7

4  CGAL::SNC_external_structure<CGAL::SNC_indexed_items, CGAL::SNC_structure<CGAL::Epick, CGAL::SNC_indexed_items, bool>>::build_external_structure                  In_place_list.h                        310  0x5555555c3417

5  CGAL::Nef_polyhedron_3<CGAL::Epick, CGAL::SNC_indexed_items, bool>::build_external_structure                                                                      SNC_const_decorator.h                  125  0x5555555f6188

6  CGAL::Nef_polyhedron_3<CGAL::Epick, CGAL::SNC_indexed_items, bool>::delegate                                                                                      Nef_polyhedron_3.h                     1071 0x5555555f6188

7  CGAL::bipartite_nary_union_sorted_combined<CGAL::Nef_polyhedron_3<CGAL::Epick, CGAL::SNC_indexed_items, bool>>                                                    bipartite_nary_union_sorted_combined.h 214  0x5555555f6188

8  CGAL::minkowski_sum_3<CGAL::Nef_polyhedron_3<CGAL::Epick, CGAL::SNC_indexed_items, bool>>                                                                         In_place_list.h                        309  0x5555555f7384

9  main                                                                                                                                                              minkowski_sum_3.cpp                    81   0x55555555d8df

10 __libc_start_main                                                                                                                                                 libc-start.c                           310  0x7ffff69ccb97

11 _start   

 

I have two questions:

1.       Is there a better (more efficient) way to do this?

2.       If not, how can I fix the segfault / what am I doing wrong?

I appreciate any hints.

Best

Raphael

----

Karlsruhe Institute of Technology (KIT)

Institute for Anthropomatics and Robotics (IAR)

High Performance Humanoid Technologies (H2T)

 

Raphael Grimm (M.Sc.)

Research Scientist

 

Adenauerring 2

Building 50.20, Room 334

76131 Karlsruhe, Germany

 

Phone: +49 721 608-47133

Fax: +49 721 608-48270

Email:

Web: https://www.humanoids.kit.edu

 

KIT - The Research University in the Helmholtz Association

 

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