Game system, method for image generation in the game system, and computer readable storage medium with game program

摘要

An opened polygon including a transparent region for maintaining a backward drawing state is drawn. Next, a mask polygon which inhibits another polygon and texture from begin forwardly drawn afterward and maintains a backward drawing state is drawn behind the drawn opened polygon so as to be superimposed by at least the transparent region thereof. Then, in the case where a new polygon is drawn to be superimposed in front of an opened polygon, behind which the mask polygon is drawn, the new polygon is drawn in a region other than the transparent region of the opened polygon. In this manner, even in the case where another polygon is drawn to be overwritten at the boundary of a plurality of polygons having a positional relationship displayed on a game picture, it is possible to maintain a three-dimensional image.