Hello there, Im currently writing a game using opengl and c++builder. All meshes are created from quadratic surfaces which are subdivided and lit by the program my problem is that i wish to use the vertex normals to peturb the surface in order to create a curved surface in certain instances (if vertex normal != 90 degrees) if == 90 degrees then surface is flat. This could be achieved using evaluators or nurbs but this would involve 16 tranformations per surface as oppossed to 8 using the method described above. Please help, in theory its a good idea.