CGAL users discussion list

["Rafael Roberto" <>]

Vincent,

just how Andreas said, if your mesh is a CGAL::Polyhedron, then the faces are oriented consistently and, in every case I SAW, they points outside the surface. It make sense to me that the normal points outside, but I don't know if a CGAL::Polyhedron will always put they normal outside.

Just to guarantee that the normal are outside and you have to invert then to point inside, you can take a vector that start at any point of the triangle and point to the center of the polyhedron. If the angle between the normal and the vector that points to the center is bigger then 90° the normal is really point outside the polyhedron and you must invert it. Because all normal are consistent, you have to do this for just one triangle.


Valeu,
Rafael Roberto