CGAL users discussion list

["Sebastien Loriot (GeometryFactory)" <>]

Before trying to make it running in parallel, did you try calling
tree.accelerate_distance_queries()?

This should greatly improve the runtime.

Sebastien.

On 9/5/19 2:33 PM, Yana Nehme wrote:
> Hi,
>
> I want to parallelise, with OpenMP, a matching process based on the AABB
> Tree.
> Indeed, we have 2 meshes: the reference ("m_poly_original") and the
> distorded model ("m_poly_degrad" having a PointMap "pm_degrad"). For each
> vertex of the distorted mesh, we compute its nearest 3D point on the surface
> of the reference model using the AABB tree structure. For parallel
> execution, we use the OpenMP parallel loop. The code is as follows:
>
> auto original_faces = faces(m_poly_original);
>
> FaceIterator orig_begin = original_faces.first;
> FaceIterator orig_end = original_faces.second;
>
> AABB_Tree tree(orig_begin, orig_end, m_poly_original);
> tree.accelerate_distance_queries();
>
> #pragma omp parallel for
> for (int i = 0; i < (int)num_vertices(m_poly_degrad); i++)
> {
>       Vertex_Descriptor vi(i);
>
>      // computes closest point and primitive id
>       Point_and_primitive_id pp =
> tree.closest_point_and_primitive(get(pm_degrad, vi));
>       auto f_nearest = pp.second; // closest primitive id
> }
>
>
> However, the program crashes with a critical error detected c0000374.
>
> Note that, I am using visual studio Express 2015 (openMp version 2.0) on
> Windows 10.
>
> It is possible to parallize the function
> AABB_tree::closest_point_and_primitive()? How can I handle this kind of
> problem?
>
> Any help would be greatly appreciated.
>
> Regards,
> Yana Nehme
>
>
>
> --
> Sent from: http://cgal-discuss.949826.n4.nabble.com/