Method for triangle subdivision in computer graphics texture mapping to eliminate artifacts in high perspective polygons
US5841443A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Feb 20, 1997 |
| Grant date | Nov 24, 1998 |
| Priority date | — |
| Expiry date | Feb 20, 2017 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG06T17/20
- WIPO fieldComputer technology
- WIPO sectorElectrical engineering
Abstract
The system and method of the present invention performs an iterative operation that subdivides selected polygons (e.g., triangles) having high perspective ratios into a plurality of smaller polygons to limit artifact creation during the rendering/texture map processes. The present invention is particularly well suited for interpolation driven rendering/texture map processes. Processing logic of the present invention analyzes each polygon stored in display list memory of a graphics accelerator or graphics subsystem and determines a perspective ratio between adjacent vertices of the polygon. If the perspective ratio is greater than a pre-selected limit, the edge bounded by the vertices is subdivided at the mid-point and new polygons are created. The process is iterative until all polygons have perspective ratios that are less than the pre-selected limit, at which time the object data can be displayed by the hardware. Perspective values (w) and three dimensional coordinates (x, y, z) for each created mid-point are calculated by averaging the perspective values at the vertices bounding the edge. Texture coordinates at the mid-point of a divided edge (umid, vmid) are calculated and then…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.