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:
May. 07, 2002
Filed:
Oct. 13, 1999
Applicant:
Inventors:
William Bilodeau, Boulder Creek, CA (US);
Michael Songy, Sunnyvale, CA (US);
Assignee:
Creative Technology Ltd., Singapore, SG;
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
G06T 1/500 ;
U.S. Cl.
CPC ...
G06T 1/500 ;
Abstract
A method for real-time shadow rendering in a 3-D graphics scene uses an inverted z-test to mark a shadow area in a stencil buffer. Front and back facing shadow volume polygons are rendered subsequent to rendering the scene and corresponding stencil buffer entries are incremented for pixels viewing the back facing polygon when the new z-test is passed and decremented for pixels viewing the front facing polygons when the new z-test is passed. The new z-test is passed for pixels having depth (z) values greater than the corresponding depth value stored z-buffer.