CGAL users discussion list

[Hugo Mercier <>]

Le 29/06/2012 16:12, Sebastien Loriot (GeometryFactory) a écrit :
> > If I want to test the intersection with a >=2-dimension primitive, I
> > think a good way is to build a Polyhedron_3 from that primitive and
> > substract it from the Nef_polyhedron.
> >
> > But what about points and lines ?
>
> You should use this [1] package for that purpose.
> The idea is to reduce intersection test at the face level.
>
> (Note that you can use a polyhedron instead of a nef-polyhedron).
>
> You can also test the intersection between two polyhedra with this package.

Thank you for your answer.

How is it related to AABB trees ?
I am currently using them to speed up intersection tests. I understand 
that "Box_intersection_d" are more general than AABB trees (especially 
in the bipartite case), but how do they behave, for instance, on the 
case of a 1-triangle-N-segments intersection test where do_intersect( 
triangle ) is called on an AABB tree built from a set of Segment_3 ?


> > About points, there is a locate( Point_3 ) method, but I cannot figure
> > out how to know if the resulting volume is the bounded one (my
> > nef_polyhedron) or the unbounded "outter" volume (A similar question has
> > been asked some time ago on this list without answer).
>
> If you constructed a nef polyhedron, if you call mark() member function
> of the volume, true means its in the model.

Thanks, it works fine.

--
Hugo Mercier
Oslandia