Incremental Updates to Scenes Illuminated by Area Light Sources

Abstract: An object space algorithm for computing shadows in dynamic scenes illuminated by area light sources is presented. A mesh with the shadow boundaries as well as other discontinuities in the illumination function, is built in a pre-processing stage and updated on-line after any interaction resulting in a change in the scene geometry. The mesh on each polygon is a 2D BSP tree stored in a winged edge data structure. To accelerate the mesh construction a number of new ideas are employed: sorting of the polygons in respect to the area source, the shadow overlap cube, BSP tree merging of the shadows. In addition a method for dynamically changing the BSP representation of the mesh and quickly identifying the vertices requiring intensity computations was developed. Preliminary experimental results indicate the strength and the potential of this method.

• Type: Conference
• Year: 1997
• Where: RT
• Authors: Yiorgos Chrysanthou, Mel Slater
• Keywords: 2d Bsp Tree, BSP Tree, Computer Graphics, Mesh, RT 1997