Patent ID: 7071938

Claim:
A computer graphics system for generating a pixel value for a pixel in an image, the pixel being representative of a point in a scene, the computer graphics system generating the pixel value to provide a soft shadow that is represented by an evaluation of an integral of a selected function over a finite extent of an area light source, the computer graphics system comprising: A. a sample point generator for generating a set of sample points representing points on the finite extent of the area light source, the sample point generator using a predetermined strictly-deterministic low-discrepancy sequence to generate the sample points; B. a function evaluator for generating a plurality of function values each representing an evaluation of said selected function at one of the sample points generated by said sample point generator, the selected function having at least one term indicative of the level of light emission from the area light source and the visibility of at least one point on the area light source in relation to the point in the scene; C. an illumination value generator for generating an illumination level value for the point in the scene as the average of said function values generated by said function evaluator; and D. a pixel value generator for using the illumination level value generated for the point in the scene in generating the pixel value.