Abstract: This paper discusses the problem of constructing a NURBS defined blending surface on two NURBS surfaces. A method for finding offset point around intersection curve between two surfaces is proposed. The method has the advantage over the traditional approach in that the offset point can be found more quickly and accurately. Any rectangular parametric surfaces can be blended as long as their offset surfaces are smooth so that intersection between a parametrically defined plane and one of surface offset can be well defined. The blending surface itself is expressed as a 2x 3 NURBS surface, which not only makes it more accurate and its fullness can be easily controlled, but also makes it possible for our system to adopt a unified way to process the surface.

Key words: NURBS surface, blending surface, procession method