Abstract: A method of forming a composite surface which is comprised of a base or primary surface and a number of features, and which satisfies certain functional objectives or requirement. Implemented in a Computer Aided Design system employed to assist in the design of automobile inner panels, the method accepts as input a feature-based information which describes the geometry of a particular inner panel, and produces as an output, a composite surface with a user-specified degree of smoothness. The method permits interactive design and modification of complex inner panel surfaces, and significantly simplifies attendant aspects of the panel design process such as numerically controlled machining.