CGAL users discussion list

["Sebastien Loriot (GeometryFactory)" <>]

On 07/22/2016 06:53 PM, Danish Manzoor Bhatti wrote:
> Hi,
>
> Over the past few weeks I've been working with CGAL for computer vision
> in robotics. I've had a lot of meshes rejected by "input >> mesh" and
> I'm not sure why. Some meshes get accepted after I clean them, others
> dont. Can someone point me to where I can find the list of criteria that
> causes CGAL::Polyhedron_3<Kernel> to reject a certain mesh? It would be
> very helpful. I've had to waste a lot of time randomly trying to clean
> meshes hoping that it will get accepted without knowing what to look for.
>
> Please help

If you can't load a mesh into a polyhedron, it means that the mesh is
non-manifold. There are a few functions in CGAL to help you:




orient_polygon_soup() [1] will change face orientation to try to turn a 
polygon soup to a valid
manifold surface. If not possible, it will duplicate vertices to make
the mesh combinatorially manifold (even if some self-intersection are
obviously introduced)

Use polygon_soup_to_polygon_mesh() [2] to turn a manifold polygon soup
into a polyhedron.


In the next release the function is_polygon_soup_a_polygon_mesh() [3]
will indicate if a polygon soup is a valid manifold surface.

Sebastien

[1] 
http://doc.cgal.org/latest/Polygon_mesh_processing/group__PMP__repairing__grp.html#gab1ea30e030c62bf018afa4578d591f19

[2] 
http://doc.cgal.org/latest/Polygon_mesh_processing/group__PMP__repairing__grp.html#gac8fe80db9800265922ce469c36d97baa


[3] 
https://cgal.geometryfactory.com/CGAL/doc/master/Polygon_mesh_processing/group__PMP__repairing__grp.html#ga8b9d12d817b5cc76f5a42d74eac75bf3