CGAL users discussion list

["Garth N. Wells" <>]

On 8 February 2012 10:43, Laurent Rineau (GeometryFactory)
<>
 wrote:
> Le mardi 07 février 2012 12:22:52 Garth Wells a écrit :
>> I've been running into some issues with mesh generation in 3D. I'm creating
>> meshes of rather simple polyhedra (tetrahedra, cubes), but have been 
>> finding
>> that the generation randomly fails at times. I'm also seeing a dependency
>> on the gcc version and optimisation level. The code at the end of this
>> message, taken from
>>
>>
>> http://www.cgal.org/Manual/latest/doc_html/cgal_manual/Mesh_3/Chapter_main.h
>> tml#Subsection_50.3.5
>>
>> runs without error with g++ 4.6.1, but with g++ 4.4.6 and the -O2 or -O3
>> flag I get the error
>>
>>     terminate called after throwing an instance of
>> 'CGAL::Precondition_exception'
>>       what():  CGAL ERROR: precondition violation!
>>     Expr: index != Subdomain_index()
>>     File: /usr/include/CGAL/Mesh_3/Mesh_complex_3_in_triangulation_3_base.h
>>     Line: 160
>>     Aborted
>>
>> I've tested with CGAL 3.8 and 3.9. The code is compiled using
>>
>>     g++ -O2 -frounding-math  test.cpp -lCGAL -lboost_thread -lmpfr -lgmp
>>
>> Any help with this would be greatly appreciated.
>
> Can you please add:
>
> #define CGAL_MESH_3_VERBOSE 1
>
> as the first line of your cpp file, recompile, and give us the output of the
> run, when it fails?
>

It get:

Inserting protection balls...
insert_corners() done. Nb of points in triangulation: 25
insert_balls_on_edges() done. Nb of points in triangulation: 610
refine_balls() done. Nb of points in triangulation: 616

Start surface scan...end scan. [Bad facets:1202]

Refining Surface...
Legende of the following line: (#vertices,#steps,#facets to
refine,#tets to refine)
(1741,1124,0,0) (328.6 vertices/s)))
Total refining surface time: 3.42021s

Start volume scan...end scan. [Bad tets:2643]

Refining...
Legende of the following line: (#vertices,#steps,#facets to
refine,#tets to refine)
(1742,1,0,2642) (250.0 vertices/s)terminate called after throwing an
instance of 'CGAL::Precondition_exception'
  what():  CGAL ERROR: precondition violation!
Expr: index != Subdomain_index()
File: /usr/include/CGAL/Mesh_3/Mesh_complex_3_in_triangulation_3_base.h
Line: 160
Aborted

Garth

> --
> Laurent Rineau, PhD
> R&D Engineer at GeometryFactory           http://www.geometryfactory.com/
> Release Manager of the CGAL Project       http://www.cgal.org/
>
>
> --
> You are currently subscribed to cgal-discuss.
> To unsubscribe or access the archives, go to
> https://lists-sop.inria.fr/wws/info/cgal-discuss
>



-- 
Garth N. Wells
Department of Engineering, University of Cambridge
http://www.eng.cam.ac.uk/~gnw20