CGAL users discussion list

[Frédéric FEYEL <>]

Thank you for your advice.

I changed my closed surface so that it contains only 3-nodes
facets, so that all facets are obviously planar.

However, the same problem is still there:

CGAL error: assertion violation!
Expr: pe_prev->facet()->plane().
has_on(pe_prev->opposite()->vertex()->point())
File: ./cgal_build/CGAL-3.2.1/include/CGAL/Nef_3/polyhedron_3_to_nef_3.h

Does anyone has some extra clues ?

Thank you very much for your help,

Best Regards,

Frederic.

Andreas Fabri a écrit :
>
> Hello,
>
> When you have facets with more than three vertices they must be
> coplanar, which might not be given if their coordinates are doubles.
> The solution is to either make them coplanar, or to triangulate
> the faces.
>
> best regards,
>
> andreas
>
>
>
>
> 
>  wrote:
>> Hello,
>>
>> I am very new to CGAL, and I am wondering if it is possible to do
>> solid/solid intersections.
>>
>> It is funny to see that infact, I have the same question as Cedric
>> Le Maitre (he sent a mail today)...
>>
>> More precisely, I have two solids described by two closed Polyhedra
>> (using 3 and 4 nodes faces).
>>
>> I would like to get the Polyhedra that represents the difference between
>> the two solids.
>>
>> I tried using the Nef_polyhedron_3 classes :
>>
>> 1- construct two Polyhedron
>> 2- construct the Nef_polyhedron from the 2 polyhedron
>> 3- intersect the 2 Nef_polyhedron
>> 4- convert the result back to a Polyhedron
>>
>> When I construct the nef associated with one of the Polyhedrons, I
>> get the following error :
>>
>> CGAL error: assertion violation!
>> Expr: pe_prev->facet()->plane().
>> has_on(pe_prev->opposite()->vertex()->point())
>> File: ./cgal_build/CGAL-3.2.1/include/CGAL/Nef_3/polyhedron_3_to_nef_3.h
>> Line: 151
>>
>> I had a look in this file, but the error is not so obvious, at least for
>> a 'CGAL-beginner' like me.
>>
>>
>> Could anyone guide me, and tell me if such operation is available in
>> CGAL, and if yes, how to achieve it ? Any help would be greatly
>> appreciated.
>>
>>
>> Best Regards,
>>
>> Frederic.
>>
>>
>
>