02/04/2003
15-462 Graphics I
28
Normals of a Plane, Method II
•Method
II: plane given by p0, p1, p2
•Points
must not be collinear
•Recall:
u £ v orthogonal to u and v
•n0 = (p1 – p0) £ (p2 – p0)
•Order
of cross product determines orientation
•Normalize
to n = n0/|n0|