Image processing system and method including perspective transformation of three-dimensional objects utilizing clipping plane positions

摘要

Perspective transformation is performed on X, Y, Z coordinate data Xe, Ye and Ze in a view volume in a viewpoint coordinate system so as to obtain X, Y, Z coordinate data Xs, Ys and Zs in a screen coordinate system. The view volume being defined by a front clipping plane and a rear clipping plane, in which: Zs=1-CZF/Ze, or Zs=CZF/Ze, or Zs=1/Ze when a difference between a Z value CZF at the front clipping plane and a Z value CZB at the rear clipping plane is substantially large. Data bits of the Zs are shifted depending on the Z value CZF, when the difference between the Z value CZF at the front clipping plane and the Z value CZB at the rear clipping plane is substantially large where the view volume is defined by the front clipping plane and the rear clipping plane, or when the view volume is defined only by the front clipping plane. Then, a hidden-surface removal operation is performed using a Z- buffer method in accordance with the Zs.