Graphics Processor Pre-Pass Visibility Culling

The patent applies preliminary action by performing a pre-pass operation before the main rendering pass to determine visibility information for all primitives. This pre-pass processes primitives to identify which fragments are visible and which are occluded, storing this information in a visibility buffer. By performing this analysis beforehand, the system can then cull invisible fragments during the main pass, eliminating redundant rendering operations and improving rendering performance without sacrificing processing flexibility.

The patent applies segmentation by dividing the rendering process into two distinct passes: a pre-pass for visibility determination and a main pass for actual rendering with culling. The pre-pass segments the work by separately analyzing primitive visibility and storing results in a visibility buffer, while the main pass uses this pre-computed information to cull invisible fragments. This segmentation reduces the complexity of implementing hidden surface removal by breaking down the complex task into manageable, sequential operations that can be efficiently processed by standard graphics hardware.

The patent applies local quality by storing visibility information at the sampling position level, where each sampling position has its own visibility status recorded in the visibility buffer. This allows the system to maintain high fragment culling precision by tracking which specific sample positions are covered by visible primitives. The local quality approach enables precise culling decisions for each fragment while the structured storage in the visibility buffer optimizes memory access patterns, reducing overall bandwidth requirements compared to alternative approaches.