Hi. Does anyone know how to identify which side of a double-sided face will the vector returned by surface normal operation be away from? Thanks. Regards, Raymond
The normal to a face at any position can be either the same direction as the normal of the underlying surface or it can be in the opposite direction of the surface normal. If it is the same as the surface normal, the face's sense relative to the surface is forward; otherwise, its sense is reversed. This is true irrespective of the sidedness of the face.
I've always wondered, what's the purpose of having both a face and a surface normal? Surface normals I can understand, do face normals serve a purpose for managing face loops?
