CGAL users discussion list

[Jari Vauhkonen <>]

Hello,

I'm a newbie with CGAL and programming overall. I've been trying to build 3D
alpha shapes from point clouds, in which I have also succeeded.

Now I'm interested in separating the points belonging to the interior, and
correspondigly to the exterior, of the alpha shape computed, and outputting 
the
point coordinates into an ASCII file.

I've got a list with Vertex_handle type and an iterator over it. Then, I have 
no
idea how to proceed: I've tried to explore for a method to convert a
Vertex_handle into a Vertex, a point representation or straight into a
coordinate string to print, with no success. What to do?

Here's a piece of my code:

        std::list<Vertex_handle> vertices;
        as.get_alpha_shape_vertices (back_inserter(vertices), cells_type);
        FILE *koe;
        koe = fopen("testi.txt", "w");
        for ( list<Vertex_handle>::iterator vert_it = vertices.begin();
           vert_it != vertices.end(); vert_it++ ) {
                Vertex_handle h = *vert_it;
                // ??????
        }
        fclose (koe);

This is probably truly amateurish, but I can't figure it out myself. Please
help!


Best regards,
  Jari