| 摘要 |
Before being used in an interactive graphics end ronment, control points defining Bezier curves are processed to determine the curvature of the patch. This value is then used to determine the number of recursive iterations required to divide the patch into a plurality of renderable polygons. A value is determined by considering the cosine of the turning angle between vectors connecting the control points of Bezier curves. For each vector connecting the control points a respective vector of unit length is calculated. Cosine values are then calculated by producing the dot product of said unit vectors. Cosine values for two turning angles are calculated for each Bezier curve and a value indicative of curvature is determined by adding these cosine values together. The curvature of the whole patch is taken to be equivalent to the curvature of the most curved curve defining the patch. <IMAGE> |
