Periodically finding origin using Triangulation_3::adjacent_vertices

[BBBBBbruce]

Hi I am using adjacent_vertices to find the neighbour vertices in a Delauney triangulated mesh, however, I am peridically get origin returned, but the mesh doesnt have origin.

typedef CGAL::Exact_predicates_inexact_constructions_kernel K;
typedef CGAL::Triangulation_vertex_base_3<K> Vb;
typedef CGAL::Triangulation_cell_base_with_info_3<unsigned int, K> Cb;
typedef CGAL::Triangulation_data_structure_3<Vb, Cb> TDS;

typedef CGAL::Delaunay_triangulation_3<K, TDS> Delaunay;
typedef K::Point_3 Point;
typedef Delaunay::Cell_handle Cell_handle;
typedef Delaunay::Vertex_handle Vertex_handle;

std::vector<Point> points;
Delaunay T(points.begin(), points.end());


//for each mesh point, the index of nearby mesh points 

for (Delaunay::Finite_vertices_iterator vit = T.finite_vertices_begin(); vit != T.finite_vertices_end(); ++vit) {
    Vertex_handle vh = vit;
    std::vector<Vertex_handle> adjacent_gridPoints_set;
    std::cout<<"grid point: "<<vh->point()<<std::endl;

    T.adjacent_vertices(vh, std::back_inserter(adjacent_gridPoints_set));
    for (auto& adjacent_vertex : adjacent_gridPoints_set) {
        std::cout<<"adjecent point: "<<adjacent_vertex->point()<<std::endl;
    }

}

the example output is here: triangulated a 8 nodes mesh, The grid point is the mesh node and the adjecent point should be the neighours. but as you noticed, each query return this point: (6.46864e-310, 0, 0). what could be the cause?

grid point: 0.517603 1 0.775815
adjecent point: 6.46864e-310 0 0
adjecent point: 0.517603 1 0
adjecent point: 0.319689 1 0.775815
adjecent point: 0.517603 0.418771 0.775815
grid point: 0.319689 0.418771 0.775815
adjecent point: 0.319689 1 0.775815
adjecent point: 0.517603 0.418771 0
adjecent point: 0.319689 1 0
adjecent point: 0.319689 0.418771 0
adjecent point: 6.46864e-310 0 0
adjecent point: 0.517603 0.418771 0.775815
grid point: 0.319689 0.418771 0
adjecent point: 0.319689 0.418771 0.775815
adjecent point: 6.46864e-310 0 0
adjecent point: 0.517603 0.418771 0
adjecent point: 0.319689 1 0
grid point: 0.517603 1 0
adjecent point: 6.46864e-310 0 0
adjecent point: 0.517603 1 0.775815
adjecent point: 0.319689 1 0.775815
adjecent point: 0.517603 0.418771 0.775815
adjecent point: 0.319689 1 0
adjecent point: 0.517603 0.418771 0
grid point: 0.319689 1 0.775815
adjecent point: 6.46864e-310 0 0
adjecent point: 0.517603 1 0
adjecent point: 0.517603 1 0.775815
adjecent point: 0.517603 0.418771 0.775815
adjecent point: 0.319689 1 0
adjecent point: 0.517603 0.418771 0
adjecent point: 0.319689 0.418771 0.775815
grid point: 0.517603 0.418771 0
adjecent point: 0.517603 1 0
adjecent point: 6.46864e-310 0 0
adjecent point: 0.319689 1 0
adjecent point: 0.319689 0.418771 0
adjecent point: 0.319689 1 0.775815
adjecent point: 0.517603 0.418771 0.775815
adjecent point: 0.319689 0.418771 0.775815
grid point: 0.319689 1 0
adjecent point: 6.46864e-310 0 0
adjecent point: 0.319689 0.418771 0.775815
adjecent point: 0.319689 0.418771 0
adjecent point: 0.517603 0.418771 0
adjecent point: 0.319689 1 0.775815
adjecent point: 0.517603 1 0
grid point: 0.517603 0.418771 0.775815
adjecent point: 0.517603 1 0
adjecent point: 6.46864e-310 0 0
adjecent point: 0.517603 1 0.775815
adjecent point: 0.319689 1 0.775815
adjecent point: 0.517603 0.418771 0

[MaelRL]

This point doesn't have "origin" as coordinate, but initialized values; it is the infinite vertex. See User Manual for explanations.

You can use T3::finite_adjacent_vertices to exclude that special vertex from the neighborhood.