| 摘要 |
PURPOSE:To prevent the rear face from being displayed on the front face by writing or not writing the color, the brightness, etc., of a pattern to be developed in a frame memory according as bits indicate the front face or the rear face at the time when the Z value of an already developed pattern and that of the pattern to be developed are equal to each other. CONSTITUTION:Generally, whether an apex string to specify a plane is given clockwise or counterclockwise to define the front face or the rear face of a three-dimensional plane, and a pattern generating part 100 knows front and rear faces of the plane to be developed on a frame memory. Consequently, they are supplied to a comparator 106 correspondingly to bits indicating '0' or '1', and contents of a frame memory 107 are rewritten only in the case of the front face when coordinate values (Z values) in the depth direction are equal to each other. Thus, the rear face is not displayed in the front. |
