System for rendering high order rational surface patches
US6057848A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Aug 27, 1997 |
| Grant date | May 2, 2000 |
| Priority date | — |
| Expiry date | Aug 27, 2017 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG06T15/04
- WIPO fieldComputer technology
- WIPO sectorElectrical engineering
Abstract
A high order surface patch rendering system. A patch is rendered by subdividing a patch until the subpatches are sufficiently flat that they can be approximated by a quadrilateral, which can then be split diagonally and written to a rasterizer in the form of two triangles. In one embodiment, the patch rendering system receives rational coordinates (X,Y,Z,W) and attribute coordinates (color, opacity, texture) of control points of the Bezier surface patch. The patch rendering system divides and subdivides the surface patch by operating on the surface patch control points to produce subpatch control points. The rational coordinates of the control points are converted to spatial coordinates, and if the current subpatch is determined to be flat, the spatial coordinates and attributes of the subpatch corner points are provided to an output buffer in the form of triangle vertices with associated attributes. The patch rendering system which includes a patch tessellation device for converting a Bezier surface patch having a set of control points to a plurality of triangles for display. The patch tessellation device comprises a patch buffer, a patch division unit, a homogeneous coordinate un…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.