CGAL users discussion list

[Sean McDuffee <>]

Ok - I'll try once more.

This is for remeshing of an input mesh.  I need to be able to compute a 3D Delaunay Triangulation on a set of vertices, then access the cells around each vertex.  Would it be best to read in the vertex positions of my original mesh by using insert from a vector<Point_3>'s I built into a Triangulation_hiearchy_3 to get the Delaunay triangulation?  Is there a good way for marking my original points in the triangulation?  I would like to then iterate through those points and possibly output an iterator over neighboring cells finite_incident_cells?  Does this sound reasonable?  Is there a more efficient way to do any of this?

Thanks,
Sean

On Tue, Mar 31, 2009 at 12:21 PM, Sean McDuffee <> wrote:

Anybody?

On Mon, Mar 30, 2009 at 1:01 PM, Sean McDuffee <> wrote:

Yes, I'm trying to remesh an input surface mesh.  I'm following Pierre Alliez's paper for variational tet meshing.  I want to compute the Delaunay triangulation for a given inputted vertex set and then for that given connectivity move the vertices.  I was hoping to use CGAL to compute the triangulation and also to use 1-ring circulators to get the info I need to move the vertices.  I don't need the entire tet mesh though.  Only a well triangulated surface is what I desire in the end.

Thanks for all the help,

Sean

On Mon, Mar 30, 2009 at 12:15 PM, Mariette Yvinec <> wrote:

Most probably what is wanted here
is a remesh of the input surface mesh

Laurent Rineau (GeometryFactory) wrote:

On Monday 30 March 2009 16:45:02 Sean McDuffee wrote:
  

Hi,

I'd like to input a surface mesh and compute it's Delaunay triangulation.
It seems I should use Polyhedron_incremental_builder_3 for reading in the
.obj file.  This will fill out a Polyhedron_3.  For a triangulation I guess
I need to somehow insert this Poly data structure into a
Delaunay_Triangulation_3 with the original Polyhedron_3 as a
SurfaceMeshComplex_2InTriangulation_3 and then use the make_surface_mesh
function to get a mesh I can output back to a .obj.  Can someone tell me if
this is the right track?  I don't seem to know how to exactly put this
together.
    

You can compute the Delaunay triangulation of *a set of points*, and not from 
a surface mesh. Maybe your surface mesh is included in the triangulation, as a 
subset of facets, but that is not the general case. If you are sure that all 
the faces of your surface are a union of facets of the Delaunay triangulation 
of its vertices, then you can compute the Delaunay triangulation of the 
vertices of the surface, and then manually mark the surface in a c2t3. I do 
not see the interest. I think I have misunderstood your goal.

  

-- 
Mariette Yvinec
Geometrica project team
INRIA  Sophia-Antipolis