Method and system for efficiently implementing two sided vertex lighting in hardware
US6597357B1 · kind B1 · utility
Assignee
Inventor
Key dates
| Filing date | Dec 20, 1999 |
| Grant date | Jul 22, 2003 |
| Priority date | — |
| Expiry date | Dec 20, 2019 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG06T2200/28
- WIPO fieldComputer technology
- WIPO sectorElectrical engineering
Abstract
In a graphics subsystem of a computer system, a method for performing front-side and back-side vertex lighting of successive vertices in the graphics pipeline without incurring pipeline stalls. The method includes computing the dot product terms for a plurality of light sources with respect to a vertex to obtain a magnitude and a sign of the dot product terms, wherein a positive dot product term corresponds to a front-side color and a negative dot product term corresponds to a back-side color. For each of the plurality of light sources having a positive dot product term, a color value corresponding to the light source for the vertex is computed. The resulting color values are multiplied and accumulated in parallel to obtain a respective front-side vertex color and back-side vertex color. The geometric orientation of the polygon corresponding to the vertex is then determined to ascertain whether the polygon is front facing or back facing. If the corresponding polygon is front facing, the front-side vertex color is output. If the corresponding polygon is back facing, the back-side vertex color is output, thereby allowing front-side and back-side vertex lighting to precede efficiently…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.