Hidden Culling in Tile-Based Computer Generated Images

摘要

A method and system is provided for culling hidden objects in a tile-based graphics system before they are indicated in a display list for a tile. A rendering space is divided into a plurality of regions which may for example be a plurality of tiles or a plurality of areas into which one or more tiles are divided. Depth thresholds for the regions, which are used to identify hidden objects for culling, are updated when an object entirely covers a region and in dependence on a comparison between a depth value for the object and the depth threshold for the region. For example, if the depth threshold is a maximum depth threshold, the depth threshold may be updated if an object entirely covers the tile and the maximum depth value of the object is less than the maximum depth threshold.

主权项

1. A method for culling non-visible objects in a tiling unit of a tile-based rendering system, the method comprising:
subdividing a rendering space into a plurality of regions, each comprising a plurality of pixels; compiling a display list for each region of the rendering space, the display list comprising object data for potentially visible objects in the region, the compiling comprising:
deriving a depth value for an object in the region;reading a depth threshold for the region from a memory;performing a comparison between the depth value for the object and the depth threshold for the region; and determining whether to cull the object for the region in dependence on the result of the comparison, such that the object is not indicated in the display list for the region; determining whether the object entirely covers the region; and, updating the depth threshold for the region in dependence on the result of the comparison and when it is determined that the object entirely covers the region.