| 摘要 |
PURPOSE:To attain the parallel processing and to speed up the processing by independently executing the face normal decision processing of a cubic at every face, irrespective of processing other faces. CONSTITUTION:An inner point extraction part 14 in a processor 12 reads out face information on one face out of a storage device 11, and selects one inner point on the plane of a polygon illustrated by the face information. An intersection detecting part 15 sets two semi-straight lines which extend to both sides of the plane with the inner point as a start and are vertical against the face, obtains the intersection between other faces comprising the cubic and each semi-straight line with the aid of the face information held in the storage device 11, and sums up the number of intersections. A normal deciding part 16 decides the semi-straight line, where a total of intersections stands at '0' or even, out of two semi-straight lines to be a face normal, and outputs the face normal information showing said semi-straight line to a storage device 13. Thus processing one face can be independently executed, thereby attaining the parallel processing. |
