02/21/2002
15-462 Graphics I
12
Assessment: Cubic B-Splines
•More
expensive than Bezier curves or patches
•Smoother
at join points
•Local
control
–How
far away does a point change propagate?
•Contained
in convex hull of control points
•Preserved
under affine transformation
•How to
deal with endpoints?
–Closed
curves (uniform periodic B-splines)
–Non-uniform
B-Splines (multiplicities of knots)