Volumetric pre-clipping method that guarantees minimal number of sample points through a volume
US6072497A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | May 30, 1997 |
| Grant date | Jun 6, 2000 |
| Priority date | — |
| Expiry date | May 30, 2017 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG06T15/30
- WIPO fieldComputer technology
- WIPO sectorElectrical engineering
Abstract
A volumetric pre-clipping method that guarantees only a minimal number of sample points along rays that pass through a volume data set will need to be processed by a volume rendering system. Pre-clipping is a two step process. First, a projection of the volume is made onto an image plane based on the orthographic or perspective view desired. Each bounding vertex of the volume data set is multiplied by the appropriate transformation matrix to transform the vertices from source space to view space. The transformed vertices establish on the view space image plane the projection outline of the volume data set. By definition, only rays cast from pixels on the image plane within this projection outline will pass through the volume data set. Pixels outside the projection outline do not need to be considered. Rays and pixels in view space are transformed back to source space by multiplication with the appropriate inverse transformation matrix for an orthographic or perspective view. Second, for each ray that passes through the volume data set, the entrance point into the volume data set and the exit point out of the volume data set are calculated. Only the sample points along a ray that fa…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.