Constraint-Based NURBS Surfaces Manipulation

This paper presents a method for applying systems of constraints at a series of points on a NURBS surface and describes an efficient technique for the interactive application. By applying systems of constraints and minimizing the changes of control net in least-square sense, geometric features (such as position, partial derivative and normal vector) at a series of selected points on a NURBS surface are modified. We also discuss shape manipulation in three special cases and the numerical examples show that this method can realize miscellaneous modification effects.