Z-buffering graphics system
US6498606B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | Jun 6, 2000 |
| Grant date | Dec 24, 2002 |
| Priority date | — |
| Expiry date | Mar 10, 2021 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG06T15/405
- WIPO fieldComputer technology
- WIPO sectorElectrical engineering
Abstract
In an image processing system for providing two-dimensional pixel images comprised of a purality of polygonal image primitives and a background, the polygonal image primitives representing a three-dimensional object, a Z buffer and a color buffer are cleared by the steps of rendering image primitives relating to foreground in the color buffer (354) and the Z buffer (353); and subsequently scanning the Z buffer and for each pixel, if the Z value is a predetermined background value such as zero (357), clearing the corresponding location in the color buffer to background color (358), and if the Z value is not the predetermined background value, clearing the Z buffer to that predetermined background value (359). In the method, either a Z buffer or a color value is written during the buffer clearing process, but never both. The pixels may be read from cache in groups, the size of a group being selected to maximize the possibility of all consecutive pixels in a group being either foreground or background pixels. Further bandwidth saving may be achieved by the use of a tile buffer and two output buffers.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.