METHOD AND APPARATUS FOR APPLYING A SHADOWING OPERATION TO FIGURES TO BE DRAWN FOR DISPLAYING ON CRT-DISPLAY

摘要

Discrimination of the condition of polygons is carried out by performing coordinate transformation from a view reference coordinate to a light source coordinate for each polygon. Then shadowing is carried out for every pixel of the polygon which is to be partially shaded. Also when multiple light sources exist, detection of the polygon is carried out by performing a coordinate transformation to each light source coordinate system for each polygon to be subjected to a shadowing operation. The detection includes detecting whether or not each polygon is the most light source side from among several polygons, thereafter intensity for display of each pixel is obtained based upon every detection result corresponding to each light source coordinate system.