Abstract
An algorithm to interpolate data points with directional constraints is given in this paper. The interpolating B-spline curve passes through the data points and assumes tangent directions at arbitrarily selected points. The advantages of the method is that the user is free to select any number of directional constraints and the method produces full parametric continuity up to C-p (- 1) for any degree p interpolation. The method is a generalization of Piegl and Tiller (The NURBS book, 2nd edn. Springer, New York, 1997] in two directions: (1) there is no restriction on the degree, and (2) no need to specify derivatives at all data points.