Extension algorithm of B-spline surfaces of degree n preserving C^n-1 continuity

Abstract

Methods of extending B-spline surfaces in conventional 3D CAD systems are usually based on linear extrapolation from sequence of control points. These methods do not always result in desired smooth surfaces fulfilling the requirements for exterior automotive parts. A new method of extending B-spline surfaces of degree n which preserves C^n-1 continuity is proposed. The method constructs new surfaces in two stages by introducing a surface with smaller intermediate curvature and a plane surface.