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:
Feb. 24, 2004
Filed:
Sep. 28, 2001
Applicant:
Inventor:
Dave Stuttard, Bristol, GB;
Assignee:
Clearspeed Technology Limited, Bristol, GB;
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
G06T 1/560 ;
U.S. Cl.
CPC ...
G06T 1/560 ;
Abstract
Shading values in a graphics processing system are determined by using approximation techniques. For example, where a Beckmann Distribution Function (BDF) is used, the shading values are determined by reformulating the BDF in terms of the scalar product of the surface normal and the viewpoint-light half-vector to produce a modified BDF. A portion of the BDF is divided into a plurality of intervals, each defined by first and second control points at its boundaries. Each interval is then approximated using a cubic approximation to produce coefficients for use in determining the shading values. In alternative embodiments, other functions are approximated.