Method and apparatus for determining level of detail for texture filtering
US6078335A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jun 1, 1998 |
| Grant date | Jun 20, 2000 |
| Priority date | — |
| Expiry date | Jun 1, 2018 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG06T15/04
- WIPO fieldComputer technology
- WIPO sectorElectrical engineering
Abstract
A method and apparatus for determining the level of detail for texture mapping applications in video graphic circuits begins by updating first and second linear components of a set of derivatives when rendering a pixel of an object in a given scan line. The first and second linear components are updated in a linear manner based on first and second increment values, respectively. The set of derivatives corresponds the changes of the texture coordinates with the changes of the physical coordinates of an object being rendered, the derivatives include .delta.s/.delta.x, .delta.t/.delta.x, .delta.s/.delta.y, and .delta.t/.delta.y--in general, the set of derivatives equals .delta.a/.delta.b=w.sup.2 *((1/w)*(.delta.(a/w)/.delta.b-(a/w)*(.delta.(1/w)/.delta.b))). When the object is being rendered on a new scan line, third and fourth linear components are updated in a linear manner based on third and fourth increment values, respectively. As the linear components are updated, their magnitudes are compared, and the one having the greatest magnitude is selected. The selected magnitude is then converted into a logarithmic scale to produce a logarithmic magnitude. The logarithmic magnitude of t…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.