Queried virtual shadow maps

ABSTRACT

Shadowing scenes by shadow mapping has long suffered from the fundamental problem of undersampling artifacts due to too low shadow map resolution, leading to so-called perspective and projection aliasing.

In this paper we present a new real-time shadow mapping algorithm capable of shadowing large scenes by virtually increasing the resolution of the shadow map beyond the GPU hardware limit.

We start with a brute force approach that uniformly increases the resolution of the whole shadow map. We then introduce a smarter version which greatly increases runtime performance while still being GPU-friendly. The algorithm contains an easy to use performance/quality-tradeoff parameter, making it tunable to a wide range of graphics hardware.

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Index Terms

• Computing methodologies

  • Computer graphics

    • Image manipulation

      • Texturing