
C i[~[ .A P T I:!i R
9
NURBS
Before discussing NURBSs, it is important to cover how curves are created in
general. There are many different types of curves: Bezier, Hermite, Catmull-Rom,
uniform B-splines, nonuniform B-splines, Kochanek-Bartels, and so on. All
curves start out as a set of points
(control vertices).
Depending on its type, the
curve will either go through these points (interpolate), get close to them (approxi-
mate), or a mix of both. Given a point on the curve, the fundamental question
that is asked is how the control points near it will influence it. Some control
points will pull the ...