Surface Extension in Smoothing of Class a Surfaces for Auto-Body

In smoothing of Class A surfaces for auto-body, the whole surface is firstly divided into many base surfaces, and then blended them into a whole surface. The base surface is often not big enough to meet the blending requirements, so it should be extended. The paper discussed the extension of Bézier curves and surfaces, and analyzed the relationships between extended curves/surfaces and vertexes. The result shows that the arrangement of control vertexes is closely related to the quality of extended curves/surfaces.