| 摘要 |
A method and system for culling a patch of surface data from one or more tiles in a tile based computer graphics system. A rendering space is divided into a plurality of tiles and a patch of surface data read. Then, at least a portion of the patch is analysed to determine data representing a bounding depth value evaluated over at least one tile. This may comprise tessellating the patch of surface data to derive a plurality of tessellated primitives and analysing at least some of the tessellated primitives. For each tile within which the patch is located, the data representing the bounding depth value is then used to determine whether the patch is hidden in the tile, and at least a portion of the patch is rendered, if the patch is determined not to be hidden in at least one tile. Preferably a display list is generated listing all tiles that have at least a portion of a patch that is not hidden. Thus culling each tessellated primitive determined to be hidden and which does not form part of the display list. |
