CGAL users discussion list

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

Le Tuesday 29 April 2014 12:19:34 Benjamin Kehlet a écrit :
> Hello
> 
> I'm trying to mesh the file demo/Polyhedron/data/couplingdown.off from
> the CGAL source tree. However, the program hits an assertion in CGAL
> during the insertion of protection balls.
> 
> I get this error message:
> 
> benjamik@benjamik-hp:~/tmp/cgal-meshing/build$ ./main
> Point p[0.0581614 -0.0161141 0.0188679], dim=1 and q[0.0547853
> -0.0329333 0.0188679], dim=1 form an edge but do not intersect !
> terminate called after throwing an instance of 'CGAL::Assertion_exception'
>   what():  CGAL ERROR: assertion violation!
> Expr: minimal_size_ > 0 || c3t3_.is_valid()
> File:
> /home/benjamik/software/cgal-4.4-install/include/CGAL/Mesh_3/Protect_edges_
> sizing_field.h Line: 370
> Aborted
> 
> This code reproduces the problem (assuming the off file is in current
> directory):
[...]

Hi Benjamin, 

Thanks for your precise and complete report.

A bug have being introduced in CGAL-4.3. An experimental modification of the 
1D-sampling algorithm of Mesh_3 have being pushed to our codebase, and was 
not 
correctly deactivated before the release. That experimental modification is 
not robust, and buggy in some cases. Here is the patch, to deactivate that 
modification, in the file include/CGAL/Mesh_3/config.h:

diff --git a/include/CGAL/Mesh_3/config.h b/include/CGAL/Mesh_3/config.h
index ddff7b1..33838d1 100644
--- a/Mesh_3/include/CGAL/Mesh_3/config.h
+++ b/Mesh_3/include/CGAL/Mesh_3/config.h
@@ -41,7 +41,7 @@
 //#define CGAL_MESH_3_OLD_MINIMUM_DIHEDRAL_ANGLE 1
 
 //experimental
-//#define CGAL_MESH_3_PROTECTION_NON_LINEAR 1
+#define CGAL_MESH_3_NO_PROTECTION_NON_LINEAR 1
 #define CGAL_MESH_3_NEW_ROBUST_INTERSECTION_TRAITS 1
 
I will push that patch to our repository, and that will be published in next 
release of CGAL. Sorry for the inconvenience.