Abstract
The method to modify the NURBS surface in this paper is not based on the change of the mathematical parameters. It presents a new surface representation for the deformed NURBS surface based on the Cao En model. The deformed surface representation is a combination of two functions: a displacement function and a function for an existing NURBS surface. There is no implied controlling grid structure over the surface. The key points can be placed anywhere in the parameter space. The point displacement constraints directly influence the final shape of the deformed surface. The results show that this method facilitates the designer in a rapid and intuitive manner in editing surfaces.