The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Jun. 23, 1998
Filed:
Feb. 21, 1996
Ricoh Company, Ltd., Tokyo, JP;
Abstract
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.