Abstract
Curve extension is a useful function in CAD systems. Disk B-Spline curve has its distinct advantages in representing a 2D region. This paper presents an algorithm for extending the disk B-Spline curve. A disk Bezier segment is used to construct the extending part and G2-continuity can be used to describe the smoothness of the joint disk. Fairness of the extending disk Bezier segment is achieved by minimizing an energy objective function. New control disks are computed by unclamping algorithm to represent the whole extended disk B-Spline curve. The experimental results demonstrate the effectiveness of our method.