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Incremental Updates to Scenes Illuminated by Area Light Sources

  • Y. Chrysanthou
  • M. Slater
Part of the Eurographics book series (EUROGRAPH)

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.

Keywords

Subdivision Scheme Critical Surface Node Edge Shadow Boundary Scene Geometry 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.

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Copyright information

© Springer-Verlag/Wien 1997

Authors and Affiliations

  • Y. Chrysanthou
    • 1
  • M. Slater
    • 1
  1. 1.Department of Computer ScienceUCL University of LondonLondonUK

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