hello,

i have some code which draws a torus (or n degrees of it) by basically sweeping a circle around another one and joining up the sections as i go along.

right… i need to calculate the vertex normals but i dont want to have to do it based on an average of face normals or anything like that. i know that if you have a sphere the vertex normal at any point is simply the same as the vertex itself ( if the middle of the sphere is at the origin) so i just want to know if there is a clever little trick i can use to calculate the normal at a particular vertex on a torus (drawn with the middle of the torus at the origin).

any ideas?