使用Projection_traits_xy_3的约束delaunay三角测量

Question

如何将Constrained_Delaunay_triangulation_2与三维数据一起使用？之后我需要显示一个网格。

从文献来看，Projection_traits_xy_3是ConstrainedTriangulationTraits_2的一个模型。如何正确地键入CDT？

typedef CGAL::Exact_predicates_inexact_constructions_kernel K;
typedef CGAL::Projection_traits_xy_3<K>  Gt;
typedef K::Point_3   Point;
typedef CGAL::Triangulation_vertex_base_2<K> Vb;
typedef CGAL::Delaunay_mesh_face_base_2<K> Fb;
typedef CGAL::Triangulation_data_structure_2<Vb, Fb> Tds;
typedef CGAL::Constrained_Delaunay_triangulation_2<K, Tds> CDT;
//-or-
typedef CGAL::Constrained_Delaunay_triangulation_2<Gt, K, Tds> CDT;
//-or what?-
typedef CGAL::Delaunay_mesh_size_criteria_2<CDT> Criteria;
typedef CGAL::Delaunay_mesher_2<CDT, Criteria> Mesher;
typedef CDT::Vertex_handle Vertex_handle;
//what should Point be?
//typedef CDT::Point Point;
int main(int argc, char *argv[])
{

    const char* fname = (argc>1)?argv[1]:"../sampledata/dtm_ground.xyz";
    std::vector<Point> points;
    std::ifstream stream(fname);
    if (!stream || !CGAL::read_xyz_points(stream,
                         std::back_inserter(points),
                         CGAL::Identity_property_map<Point>()))
    {
        std::cerr << "Error: cannot read file " << fname << std::endl;
        return EXIT_FAILURE;
    }
    CDT cdt(points.begin(), points.end());
    //CGAL::refine_Delaunay_mesh_2(cdt, Criteria(0.125, 0.5));
    //std::cout << "Number of vertices: " << cdt.number_of_vertices() << std::endl;
    return EXIT_SUCCESS;
}

Answer 1

所有三角测量类的traits类参数必须为Gt。受约束三角剖分的按范围插入构造函数需要一系列约束。您可以使用insert函数。