Patent ID: 7920148

Claim:
A system to apply a smoothing filter during anti-aliasing at a post-rendering stage, the system comprising: a three-dimensional renderer to render a three-dimensional scene, an edge detector configured to communicate with the three-dimensional renderer, the edge detector to read values of a depth buffer and to apply edge detection criteria to the values of the depth buffer in order to detect an object edge within the three-dimensional scene; and a smoothing filter configured to communicate with the edge detector, the smoothing filter to read values of a color buffer and the apply a smoothing coefficient to the values of the color buffer, wherein the values of the color buffer comprise a pixel sample at the detected object edge; wherein the edge detection criteria comprises: | z 2 +z 0−2 ×z 1|≧Thresh×( Q−z 1) where the variable z1 designates a depth value of a current pixel sample, the variables z0 and z2 designate depth values of adjacent pixel samples, the variable Thresh designates a predefined threshold value, and the variable Q designates a depth coefficient given by: Q = z far z far - z near .