CGAL users discussion list

[Peter Hachenberger <>]

Hi Olivier,

On Wed, 2007-05-02 at 11:38 +0200, olivier stab wrote:
> Hello everybody,
> 
> I first want to thanks all the CGAL developers : my program which use 
> CGAL 3d nef module begins to give the result I expected :-). But... I 
> still have 2 questions :
> 
> 1) In the binary operation between two 3d nef polyhedrons :
> During execution, just at the end of the function "binary_operation" 
> (Line 1245 in SNC_decorator.h)  the assertion "sim.simplify" is 
> (sometime) not true and the program ends !
> I would like to know if somebody already had this problem...
> What mean the assertion "simplify" (I didn't find an explanation in the 
> CGAL documentation) ?

Actually, this assertion should not occur. Probably, you are not doing
wrong, here. Can you send me the files that cause the problem and tell
me which binary operation you apply on them and which Kernel you use.
Then I try to find the error.

> 2) How can I convert a Nef_Polyhedron_3 which is not simple (a face has 
> a hole in it) in a Polyhedron_3 (which I visualize later in VRML format) ?
> Is there already a simple procedure which do so or do I have to program 
> an algorithm ( which for example triangulate the non-simple-face ) ?

We still don't have such a conversion tool. It moved in a high position
on my agenda, especially since we are just about to finish a new
triangulation, but I did not do it yet.

Peter