Actually, I'm not sure the triangle vertices generated by the example " make_3d_output " is correct or not.
As in the method " write_output ", it tries to compute triangle and vertex lists. However, it seems just using a few lines to calculate 3 verteces of an triangle, instead of using any famous trianglation method such as Delaunay triangulation. And most of verteces generated in output file are very large, some points are even located ten thousand or hundred thousand away from the origin. That's why I think that " vsrl_3d_output " is incorrect.