Abstract
We propose a novel method to remove irregularities of B-spline surfaces via smoothing circular highlight lines. A circular highlight line is defined as a set of points on a surface where the distance between a circular light and an extended surface normal at the circular highlight line is zero. It is very sensitive to the change of the directions of normal vectors of the surface, and hence can detect surface irregularities by observing its behavior. This method of correcting surface irregularities is very intuitive and allows non-skilled person to generate surfaces that can satisfy the requirements imposed by the downstream applications. Nonlinear equations that relate the difference between the circular highlight lines of the current surface and the target circular highlight lines in the parameter space of the surface are formulated in terms of control points of the surface to be modified. The nonlinear governing equations are solved by Newton's method.
