Picture-drawing method and apparatus, and recording medium
US6329988A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Sep 9, 1998 |
| Grant date | Dec 11, 2001 |
| Priority date | — |
| Expiry date | Sep 9, 2018 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG06T15/506
- WIPO fieldComputer technology
- WIPO sectorElectrical engineering
Abstract
A picture drawing method capable of expressing a three-dimensional feeling on a diffuse reflection surface of an object by considering indirect reflection from a ground surface with a simple algorithm. In this method, a diffuse reflection quantity a surface of the object receives from the ground surface at an angle between the normal vector of the object surface and the normal vector of the ground surface is calculated using a light quantity from a ground light source regarded as existing on the ground surface, an atmospheric damping coefficient and a distance between the object and the ground surface as parameters and stored in the form of a table. By specifying the parameter, the diffuse reflection quantity from the ground surface over the angular range of 0 to .pi. is obtained from the table. Further, an object luminous intensity which develops the color of the object on the object surface is obtained from the diffuse reflection quantity and an object diffuse reflection coefficient. In addition, an object luminous intensity which develops the color of the ground light source on the object surface is obtained from the diffuse reflection quantity.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.