“Adaptive shadow maps” by Fernando, Fernandez, Bala and Greenberg

  • ©Randima Fernando, Sebastian Fernandez, Kavita Bala, and Donald P. Greenberg

Conference:


Type(s):


Title:

    Adaptive shadow maps

Presenter(s)/Author(s):



Abstract:


    Shadow maps provide a fast and convenient method of identifying shadows in scenes but can introduce aliasing. This paper introduces the Adaptive Shadow Map (ASM) as a solution to this problem. An ASM removes aliasing by resolving pixel size mismatches between the eye view and the light source view. It achieves this goal by storing the light source view (i.e., the shadow map for the light source) as a hierarchical grid structure as opposed to the conventional flat structure. As pixels are transformed from the eye view to the light source view, the ASM is refined to create higher-resolution pieces of the shadow map when needed. This is done by evaluating the contributions of shadow map pixels to the overall image quality. The improvement process is view-driven, progressive, and confined to a user-specifiable memory footprint. We show that ASMs enable dramatic improvements in shadow quality while maintaining interactive rates.

References:


    1. J. A. Ferwerda, S. N. Pattanaik, P. Shirley, and D. P. Greenberg. A Model of Visual Masking for Computer Graphics. In Proceedings of SIGGRAPH 97, Computer Graphics Proceedings, Annual Conference Series, pages 143-152, August 1997. T. Whitted, editor.
    2. N. Greene and M. Kass. Hierarchical Z-Buffer Visibility. In Proceedings of SIG- GRAPH 93, Computer Graphics Proceedings, Annual Conference Series, pages 231-240, August 1993. J. T. Kajiya, editor.
    3. E. A. Haines and D. P. Greenberg. The Light Buffer: a Shadow Testing Accelerator. IEEE Computer Graphics and Applications, 6(9):6-16, September 1986.
    4. J. C. Hourcade and A. Nicolas. Algorithms for Antialiased Cast Shadows. Computer and Graphics, 9(3):259-265, 1985.
    5. T. Lokovic and E. Veach. Deep Shadow Maps. In Proceedings of SIGGRAPH 2000, Computer Graphics Proceedings, Annual Conference Series, pages 385- 392, July 2000. K. Akeley, editor.
    6. T. Moller and E. A. Haines. Real-Time Rendering. A. K. Peters, Massachusetts, 1999.
    7. W. T. Reeves, D. H. Salesin, and R. L. Cook. Rendering Antialiased Shadows with Depth Maps. Computer Graphics (Proceedings of SIGGRAPH 87), 21(4):283-291, July 1987. M. C. Stone, editor.
    8. L. R. Wanger, J. A. Ferwerda, and D. P. Greenberg. Perceiving Spatial Relationships in Computer-Generated Images. IEEE Computer Graphics and Applications, 12(3):44-58, May 1992.
    9. L. Williams. Casting Curved Shadows on Curved Surfaces. Computer Graphics (Proceedings of SIGGRAPH 78), 12(3):270-274, August 1978. R. L. Phillips, editor.
    10. L. Williams. Pyramidal Parametrics. Computer Graphics (Proceedings of SIG- GRAPH 83), 17(3):1-11, July 1983. P. Tanner, editor.
    11. A. Woo, P. Poulin, and A. Fournier. A Survey of Shadow Algorithms. IEEE Computer Graphics and Applications, 10(6):13-32, November 1990.


ACM Digital Library Publication:



Overview Page: