THREE-DIMENSIONAL SHAPE DRAWING DEVICE AND THREE-DIMENSIONAL SHAPE DRAWING METHOD

摘要

A three-dimensional drawing device for drawing a three-dimensional shape at high speed. An upper-order bit comparing section compares the upper-order bit held in an upper-order Z buffer memory with the upper-order bit of the depth value calculated by a depth value calculating section. If the upper-order bits agree with each other, a lower-order bit comparing section compares the lower-order bit of the depth value held in a lower-order bit Z buffer memory with the lower-order bit of the depth value calculated by the depth value calculating section. A record update section updates the upper-order bit of the depth value held in the upper-order Z buffer memory and the lower-order bit held in the lower-order Z buffer memory if the depth indicated by the upper-order bit of the depth value calculated by the depth value calculating section is shallow, and updates the lower-order bit held in the lower-order Z buffer memory if the depth indicated by the lower-order bit of the depth value calculated by the depth value calculating section is shallow.