| 摘要 |
PROBLEM TO BE SOLVED: To provide sub polygons for constituting a smooth three-dimensional shape from a polygon. SOLUTION: A Bezier curve as an interpolation line B12 for interpolating the vertexes P1 and P2 of a quadrilateral polygon P1 P2 P4 P3 is obtained based on normal vectors n1 and n2 and the interpolation line B34 for interpolating the vertexes P3 and P4 is obtained based on the normal vectors n3 and n4 . Then, on the interpolation lines B12 and B34 , interpolation points P12 and P34 are obtained. Further, the interpolation line B13 for interpolating the vertexes P1 and P3 and the interpolation line B24 for interpolating the vertexes P2 and P4 are similarly obtained as well and the interpolation points P13 and P24 are obtained on the interpolation lines B13 and B24 . Then, the interpolation line B1234 for interpolating the interpolation points P12 and P34 is also similarly obtained and the interpolation point P1234 is obtained on the interpolation line B1234 . Thus, the quadrilateral polygon P1 P2 P4 P3 is divided into the four sub polygons of the quadrilateral polygons P1 P12 P1234 P13 , P12 P2 P24 P1234 , P1234 P24 P4 P34 and P13 P1234 P34 P3 . |
