How to remove duplicated vertices in half-edge mesh

[morgan-bc]

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Issue Details

I want to process dirty triangle meshes which may include many duplicated vertices and non-manifold faces using half-edge structure. I use openmesh to read the mesh. Is there any method in CGAL can remove duplicated vertices and construct right half-edge strcuture ?

Environment

• Operating system: Windows
• Compiler: VS2019
• CGAL version: 5.1

[MaelRL]

You could switch back your mesh to a simple polygon soup, repair it, and then use CGAL's orientation functions which will duplicate your non-manifold elements as to get a valid 2D halfedge data structure.

This code is pretty much this pipeline, reading a polygon soup as input. All these functions are documented if you want further information about their inner workings (doc.cgal.org).

[tub-sgg]

Does this work?

    std::vector<Kernel::Point_3> points;
    std::vector<CGAL_Polygon> polygons;
    CGAL::Polygon_mesh_processing::polygon_mesh_to_polygon_soup(in,points,polygons);
    //remove duplicated points and polygons
    CGAL::Polygon_mesh_processing::orient_polygon_soup(points,polygons);
    CGAL::Polygon_mesh_processing::merge_duplicate_points_in_polygon_soup(points,polygons);
    CGAL::Polygon_mesh_processing::merge_duplicate_polygons_in_polygon_soup(points,polygons);
    SMesh out;
    CGAL::Polygon_mesh_processing::repair_polygon_soup(points,polygons,
                                                       CGAL::parameters::erase_all_duplicates(true).
                                                       require_same_orientation(true));

    CGAL::Polygon_mesh_processing::polygon_soup_to_polygon_mesh(points,polygons,out);

I tried in this way but the dupicated vertices are not removed

[sloriot]

orient_polygon_soup() should be the last step before polygon_soup_to_polygon_mesh().