Patent ID: 6525726
Filing Date: 2003-02-25
Classification: G06T

Abstract:
A method for use in a processor to be used in a data processing system comprising a frame buffer and a Z-buffer, the method operating to cull occluded polygons from a scene being assembled in the frame buffer and comprising:rendering polygons in the scene in depth order, starting with a closest polygon, and storing them in the Z-buffer; as polygons are rendered, evaluating whether a coverage parameter has been satisfied and if so, constructing a hierarchical Z-buffer from the Z-buffer; and comparing subsequent polygons to the hierarchical Z-buffer to determine whether they are occluded and if so, culling them; wherein the coverage parameter is proportional to an estimated cost of constructing and using the hierarchical Z-buffer less an estimated cost of rendering an expected number of occluded polygons.