ABSTRACT
If b = [x,y,z,w]T , then b = [x /w, y / w, z / w ]T. A , B matrices L, M lines in projective space B J1, B™ Bernstein polynomials of degree n e l , e2, e3 short for [1,0,0]T, [0,1,0]T, and[0 ,0 ,1]T ]Ed d-dimensional euclidean space D d f directional derivative of / in the direction d Ai difference in parameter intervals (i.e., Ai = Ui+i — Ui) Ar iterated forward difference H f cubic Hermite polynomials P control polygon
$ an affine or projective map A an interval in a knot sequence 11v| | (euclidean) length of the vector v xu u-partial of x(u, v)
