Graphics data handling system for CAD workstation
US4549275A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Jul 1, 1983 |
| Grant date | Oct 22, 1985 |
| Priority date | — |
| Expiry date | Jul 1, 2003 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG09G5/14
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
In this graphics data handling system a CAD workstation cooperates with the host computer which stores a site list representation of a complex three dimensional structure. Backdrop viewfile representation of the structure, advantageously with hidden surfaces removed, are established in vector format by data transformation from the site list. Bit map raster views are derived from the backdrop viewfiles, and are stored in a pixel memory. Video screen images of selected views of the structure are derived by readout of the raster view data from the pixel memory. During panning of the video screen display, when the image nears the edge of a raster view, a strip of data in that raster view, in the region opposite the direction of panning travel, is deleted. This is replaced by new data from a strip of the backdrop viewfile representing the portion of the structure immediately contiguous to the existant raster view in the direction of panning travel. With this arrangement, toroidal panning is implemented that permits the user to pan across a view of the structure which is far larger than encompassed by an individual raster view.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.