Circle approximation using integral B-splines

A method to approximate a circular are of any sweep angle with integral B-spline curves of any degree is presented. The idea is to interpolate end derivatives as well as some internal points with integral B-splines of given degree and continuity. The critical element is the choice of the right end derivative directions and magnitudes. The points and the derivatives at these locations are sampled uniformly using the trigonometric equation of the circle. The method is very general in that any degree and any level of parametric continuity can be specified. (C) 2003 Elsevier Science Ltd. All rights reserved.