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- From: Joe C <>
- To:
- Subject: Re: [cgal-discuss] AABBTree primitives or objects problem
- Date: Fri, 4 Dec 2009 09:52:17 -0800
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Hi Camille,
To add one more question in this thread:
Can I mix the use of Kernels in AABB tree? For example, use
exact_predicates_exact_constructions kernel for Polyhedron and
Simple_cartesian<double> for a segment to detect the intersection. I
used to use these two kernels for AABB tree in CGAL 3.4. But all the
examples I found in CGAL 3.5 use the same kernel for AABB tree and the
query geometry (ray, segment...).
Thanks.
Joe
On 12/3/09, Camille Wormser
<>
wrote:
>> the tree.number_of_intersected_primitives(Segment) gives me 5
>> intersections. But if I use the code to test what type of objects
>> are. only 3
>> are Point_3. What are the other 2?
>
> Hi Roberto,
> This is a typical robustness issue: I guess you use the
> exact_predicates_inexact_constructions kernel. In such a case, the
> do_intersect predicate used to answer the number_of_intersections
> query is exact. Hence the answer 5. On the other hand, the
> intersection constructions are not, and I suspect that they simply do
> not find any intersection for the two missing cases (I assume from
> your message that the code did not find any segment intersection).
>
> Of course, it would be better if the predicates and the constructions
> were consistent in the exact_predicates_inexact_constructions kernel
> (i.e. Always returning a non empty construction if the predicate said
> so). This is on some todo-list, but it is a delicate question. (note
> that it is not really AABB-tree related)
>
> Best
> --
> Camille
>
>
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- [cgal-discuss] AABBTree primitives or objects problem, robertolam, 12/03/2009
- Re: [cgal-discuss] AABBTree primitives or objects problem, Camille Wormser, 12/03/2009
- Re: [cgal-discuss] AABBTree primitives or objects problem, Roberto Lam, 12/04/2009
- Re: [cgal-discuss] AABBTree primitives or objects problem, Camille Wormser, 12/04/2009
- Re: [cgal-discuss] AABBTree primitives or objects problem, Roberto Lam, 12/04/2009
- Re: [cgal-discuss] AABBTree primitives or objects problem, Camille Wormser, 12/04/2009
- Re: [cgal-discuss] AABBTree primitives or objects problem, Joe C, 12/04/2009
- Re: [cgal-discuss] AABBTree primitives or objects problem, Joe C, 12/07/2009
- Re: [cgal-discuss] AABBTree primitives or objects problem, Roberto Lam, 12/04/2009
- Re: [cgal-discuss] AABBTree primitives or objects problem, Camille Wormser, 12/03/2009
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