CGAL users discussion list

["Sebastien Loriot (GeometryFactory)" <>]

Could you dump a problematic mesh and send it to me?

put right after the call to facets_in_complex_3_to_triangle_mesh()
std::ofstream("scaffold.off") << std::setprecision(17) scaffold;

Thanks!

Sebastien.

On 10/5/20 5:52 PM, Kim ( via cgal-discuss 
Mailing List) wrote:
> Hi everyone,
>
> I am using make_mesh_3 to mesh an implicit domain and subsequently
> extracting the surface triangulation, clipping it and doing some other
> post-processing.
>
> typedef CGAL::Exact_predicates_inexact_constructions_kernel Kernel;
> typedef CGAL::Parallel_tag Concurrency_tag;
> typedef CGAL::Polyhedron_3<Kernel, CGAL::Polyhedron_items_with_id_3>
> PolygonMesh;
> typedef CGAL::Labeled_mesh_domain_3<Kernel> Implicit_domain;
> typedef CGAL::Mesh_triangulation_3<Implicit_domain, CGAL::Default,
> Concurrency_tag>::type VTr;
> typedef CGAL::Mesh_complex_3_in_triangulation_3<VTr> C3t3;
> typedef CGAL::Mesh_criteria_3<VTr> Mesh_criteria;
>
> Implicit_domain domain = Implicit_domain::create_implicit_mesh_domain(
>      myImplicitFunction, boundBox);
>
> Mesh_criteria criteria(CGAL::parameters::facet_angle = facetAngle,
>      CGAL::parameters::facet_size = facetSize,
>      CGAL::parameters::facet_distance = facetDistance);
>
> C3t3 c3t3 = CGAL::make_mesh_3<C3t3>(domain, criteria,
> CGAL::parameters::manifold())
>
> PolygonMesh scaffold;
> CGAL::facets_in_complex_3_to_triangle_mesh(c3t3, scaffold);
>
> // Clip mesh
> PolygonMesh outer_shell;
> CGAL::Polygon_mesh_processing::polygon_soup_to_polygon_mesh(points,
> polygons, outer_shell);
>
> CGAL::Polygon_mesh_processing::remove_isolated_vertices(scaffold); //
> Temporary fix to bug!!!
> if( CGAL::Polygon_mesh_processing::clip(scaffold, outer_shell,
> CGAL::parameters::clip_volume(true).use_compact_clipper(true)) == false)
>      std::cout << "\n WARNING: Scaffold and clipper have only been
> corefined!" << std::endl;
>
> // Remove all but the largest component
> CGAL::Polygon_mesh_processing::keep_largest_connected_components(scaffold,
> 1);
>
> // Reorient all faces coherently
> if (CGAL::is_closed(scaffold) == true) {
>      CGAL::Polygon_mesh_processing::orient(scaffold,
> CGAL::parameters::outward_orientation(true));
> } else {
>      std::cout << "\n WARNING: Polygon has border edges!" << std::endl;
> }
>
> The problem I am experiencing is that although I have specified I want a
> manifold mesh make_mesh_3 does not seem to always output one. Some inputs
> seem to always result in a non-manifold mesh while others may result in a
> non-manifold mesh occasionally without any change in inputs. I get the same
> behavior regardless of whether I use mesh optimizations or disable them. Am
> I doing something incorrectly?
>
> Kind regards,
> Kim
>
>
>
> --
> Sent from: http://cgal-discuss.949826.n4.nabble.com/