Shadow Penumbras for Complex Objects by Depth-Dependent Filtering of Multi-Layer Depth Images

  • Brett Keating
  • Nelson Max
Part of the Eurographics book series (EUROGRAPH)


This paper presents an efficient algorithm for filtering multi-layer depth images (MDIs) in order to produce approximate penumbras. The filtering is performed on a MDI that represents the view from the light source. The algorithm is based upon both ray tracing and the z-buffer shadow algorithm, and is closely related to convolution methods. The method’s effectiveness is demonstrated on especially complex objects such as trees, whose soft shadows are expensive to compute by other methods. The method specifically addresses the problem of light-leaking that occurs when tracing rays through discrete representations, and the inability of convolution methods to produce accurate self-shadowing effects.


Computer Graphic Depth Image Blocker Image Filter Size Convolution Method 


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Copyright information

© Springer-Verlag/Wien 1999

Authors and Affiliations

  • Brett Keating
    • 1
  • Nelson Max
    • 1
  1. 1.Lawrence Livermore National Laboratory and UC DavisUSA

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