CGAL users discussion list

["Sebastien Loriot (GeometryFactory)" <>]

Hansjoerg Seybold wrote:
> Hello,
> Hello I would like to calculate interpolated values from vertices on a 
> 2d mesh.
> My problem is as follows:
> - I have a mesh given by vertices and constraints (i know the boundary 
> and the partitioning of the space (holes) )
>
> -  With this information i would like to create a cgal mesh to perform 
> interpolation operations of lets say the velocity field stored in the
>    vertices.
>
> I saw the cgal interpolation page and the point location page for the 
> triangulation.
> Is it also possible to use the triangulation hierarchy on a mesh for 
> efficient point location.
> I need a mesh to determine what is inside and what is outside as the 
> domain has holes or is there a simpler way to perform interpolation/and 
> determining inside/outside like in the mesh case.
>  
> Thank you very much
>    hj
From what I understand, you have a surface mesh with hole that you 
computed (not using CGAL surface mesher) and you want:
1) determine whether a point is on your surface
2) use CGAL::surface_neighbor_coordinates_3 only on points detected on
   your surface

For 1) using AABB_tree and closest_point_and_primitive might help
(http://www.cgal.org/Manual/latest/doc_html/cgal_manual/AABB_tree/Chapter_main.html#Section_62.6).

Using the triangulation hierarchy will be complicated as you first need
to have a your surface included into a 3D triangulation.

S.