(The Eurographics Association, 2004) Li, Q.; Gershon Elber and Nicholas Patrikalakis and Pere Brunet
This paper presents an implicit curve and surface design technique that uses smooth unit step functions. With the proposed method, an implicit curve or surface can be generated by inputting a sequence of points together with the normals at these points of the curve or surface to be designed. By choosing appropriate smooth unit step functions, these curves and surfaces can be designed to any required degree of smoothness.