CGAL users discussion list

[Andreas Fabri <>]

dfwang wrote:
> Dear CGALers
>
> For a given closed triangle mesh, how to make sure that the normal of 
> each triangle points to the inside of the closed surface in CGAL?
>
> Any comments are appreciated.
>
> Best wishes,
> Vincent

Hi Vincent,

if the mesh is in a CGAL::Polyhedron already then the faces are
oriented consistently already, so determining inside/outside for
one face plus propagation should do the job.

If you just have a triangle soup (std::list<CGAL::Triangle_3<K>>)
then you first have to orient your triangles consistently.
There is no out-of the box function in CGAL. It would be a good idea
though.

andreas