Real-time lighting method using 3D texture mapping

摘要

The present invention includes a method and system for providing real- time realistic lighting to graphics objects within a computer controlled graphics display system utilizing 3D texture mapped light values. The present invention generates and utilizes a 3D texture map indicating light intensity values with a predefined 3D graphics region. In generating the 3D texture map light values, the present invention selects a point (x, y, z) within the 3D graphics region that is to be displayed on a display screen and determines which light sources contribute to the illumination of the point. Based on the light sources that do contribute to the illumination of the point, the original intensity of each light source and its distance from the point are determined. Based on a determined distance formula, the attenuation of each light source is determined with respect to the point. Based on the attenuation and intensity data, the light intensity value of the point is determined. These steps repeat until the light intensity of every point of the 3D graphics region is determined. What results is a 3D light "texture map" of light intensity values representing light intensity values of the 3D graphics region. The computer stores the 3D light texture map in computer readable memory. The system also takes into account reflected light within a 3D graphics region by reiterating the above. Based on polygon vertices, texture coordinates, and the light intensity value of each point, the rendering process displays a properly lit graphics scene on a display.