CGAL users discussion list

["Sebastien Loriot (GeometryFactory)" <>]

Indeed, we did change that in the master branch because it was a bit 
restrictive. It will be included in CGAL-4.14 and is available in the
master branch.

See the master documentation here:
https://cgal.geometryfactory.com/CGAL/doc/master/AABB_tree/classCGAL_1_1AABB__face__graph__triangle__primitive.html#a0d5df69b8c98da3befcbf7df511f9a97

The minimal patch is:
https://github.com/CGAL/cgal/pull/3370

Sebastien.



On 12/19/2018 02:25 PM, Lucio Santi wrote:
> Thank you, Andreas.
>
> I've already read that page and in fact my code is using 
> OneFaceGraphPerTree set to CGAL::Tag_false. However, the primitive ID is 
> still a plain face index. The class CGAL::SM_Face_index does not seem to 
> have a way of referencing the surface mesh where that face comes from. 
> Am I missing something?
>
> On Wed, Dec 19, 2018 at 10:05 AM Andreas Fabri 
> < 
> <mailto:>> wrote:
>
>     Hello,
>
>     Please have a look at
>
>     
> https://doc.cgal.org/latest/AABB_tree/classCGAL_1_1AABB__face__graph__triangle__primitive.html
>
>     OneFaceGraphPerTreeis either |CGAL::Tag_true| or |CGAL::Tag_false|.
>     In the former case, we guarantee that all the primitives will be
>     from a common |FaceGraph
>     <https://doc.cgal.org/latest/BGL/classFaceGraph.html>| and some data
>     will be factorized so that the size of the primitive is reduced. In
>     the latter case, the primitives can be from different graphs and
>     extra storage is required in the primitives. The default is
>     |CGAL::Tag_true|.
>
>
>     Best,
>
>     Andreas
>
>     On 12/19/2018 2:00 PM, Lucio Santi wrote:
> >     Hello,
> >
> >     I have an AABB tree storing triangular faces coming from different
> >     surface mesh instances. I'm using that data structure to compute
> >     intersections with rays, but currently the primitive ID that I
> >     obtain for each intersection query is just a face index (i.e., an
> >     instance of CGAL::Surface_mesh<Point_3>::Face_index). I would like
> >     to know which surface mesh this face belongs to. Is there a clean
> >     way to do this? I was thinking of providing my own AABB primitive
> >     somehow, but I'm not sure if this is the proper way to do it (and
> >     in fact I'm not even sure how this can be done).
> >
> >     Thanks in advance for your help,
> >
> >     Lucio
>
>     -- 
>     Andreas Fabri, PhD
>     Chief Officer, GeometryFactory
>     Editor, The CGAL Project
>
>     phone: +33.492.954.912    skype: andreas.fabri