CGAL users discussion list

[Benjamin Kehlet <>]

2014-04-29 14:05 GMT+02:00 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.

That worked very well! Now, however, I get this one when trying to
mesh file "handle.off" in the same directory.

terminate called after throwing an instance of 'CGAL::Precondition_exception'
  what():  CGAL ERROR: precondition violation!
Expr: dimension() >= 2
File: 
/home/benjamik/software/cgal-4.4-install/include/CGAL/Regular_triangulation_3.h
Line: 373
Aborted (core dumped)

Just replace the filename and change the variable "cs" (just before
the mesh criteria is set) to 0.075 to reproduce.

Benjamin

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