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["Laurent Rineau (GeometryFactory)" <>]

On Sunday 11 April 2010 17:02:55 Zhonggui Chen wrote:
> Hi Laurent,
> 
> Thanks for your reply!
> 
> Actually I want to initialize the C3t3 as the input for the
> CGAL::perturb_mesh_3() function.
> I tried your method, but it doesn't work. The output .mesh file containts
> only the points I inserted, no facets or tetrahehra. Any other information
> I should provide to the C3t3?
> 
>  Here are my codes:
> ------------------------------------------
>     Polyhedron polyhedron;
>     Build_mesh<HalfedgeDS> builder(boundary);
>     polyhedron.delegate(builder);
>     Mesh_domain domain(polyhedron);
> 
>     C3t3 c3t3;
>     for (int i=0; i<tetmesh->nb_vertices(); i++)
>     {
>       // insert points
>  c3t3.triangulation().insert(Point(tetmesh->vertices_[i].point_[0],tetmesh-
> >vertices_[i].point_[1],tetmesh->vertices_[i].point_[2])); }
> 
>     CGAL::perturb_mesh_3(c3t3, domain, time_limit=300, sliver_bound=10);
> 
>     std::ofstream medit_file("out_1.mesh");
>     c3t3.output_to_medit(medit_file);
> ------------------------------------------------------------------
> 
> --zhong

You are trying to do something really curious. CGAL::perturb_mesh_3 is 
designed to work on a c3t3 produced with CGAL::create_mesh_3 or 
CGAL::refine_mesh_3 (in the same Mesh_3 package).

Before your call to perturb_mesh_3, you could try to call refine_mesh_3 with 
special cells and facets criteria that always say "the element is good". That 
way, the mesh would not be refined, but at least the c3t3 object would be 
correctly filled with facets and cells. But you will probably not be happy 
with the result, because the set of facets of the c3t3 will probably not 
approximate your surface correctly, without any refinement (but if your 
surface is equal to the set of facets of the Delaunay triangulation of its 
point, restricted to itself, see the literature about "restricted Delaunay 
triangulations").

-- 
Laurent Rineau, PhD
R&D Engineer at GeometryFactory           http://www.geometryfactory.com/
Release Manager of the CGAL Project       http://www.cgal.org/