摘要 |
In a process where an object fades-in/fades-out, a rate of transparency change is set. A writing threshold is obtained according to the rate of change of the transparency of the object. Polygons included in the object are sequentially processed, and an ± value of the processed polygon is obtained according to the rate of change of the transparency. When a Z value of the polygon is smaller than that registered in a Z-buffer, the polygon is drawn in a frame buffer. The Z value of the polygon is written to the Z-buffer only when the current ± value is larger than the threshold. When a Z value of the polygon is larger than that registered in the Z-buffer, the polygon is not drawn in the frame buffer. |