Abstract
Shadow mapping has been subject to extensive investigation, but previous shadow map algorithms cannot usually generate high-quality shadows with a small memory footprint. In this paper, we present compressed shadow maps as a solution to this problem. A compressed shadow map reduces memory consumption by representing lit surfaces with endpoints of intermediate line segments as opposed to the conventional array-based pixel structures. Compressed shadow maps are only discretized in the vertical direction while the horizontal direction is represented by floating-point accuracy. The compression also helps with the shadow map self-shadowing problems. We compare our algorithm against all of the most popular shadow map algorithms and show, on average, order of magnitude improvements in storage requirements in our test scenes. The algorithm is simple to implement, can be added easily to existing software renderers, and lets us use graphics hardware for shadow visualization.
Similar content being viewed by others
References
Akenine-Möller T, Haines E (2002) Real-time rendering, 2nd edn. A.K. Peters, Natick, Massachusetts
Brabec S, Annen T, Seidel H-P (2002) Practical shadow mapping. J Graph Tools 7(4):9–18
Cormen TH, Leiserson CE, Rivest RL, Stein C (2001) Introduction to algorithms, 2nd edn. MIT Press, Cambridge
Fernando R, Fernandez S, Bala K, Greenberg DP (2001) Adaptive shadow maps. In: Fiume E (ed) SIGGRAPH 2001, Computer Graphics Proceedings. ACM Press, New York, pp 387–390
Grant C (1992) Visibility algorithms in image synthesis. Dissertation, University of California
Lane JM, Carpenter LC, Whitted T, Blinn JF (1980) Scan line methods for displaying parametrically defined surfaces. Commun ACM 23(1):23–34
Lokovic T, Veach E (2000) Deep shadow maps. In: Akeley K (ed) Proceedings of SIGGRAPH 2000, Computer Graphics Proceedings. ACM Press, New York, pp 385–392
Reeves WT, Salesin DH, Cook RL (1987) Rendering antialiased shadows with depth maps. In: Proceedings of ACM SIGGRAPH 87, Computer Graphics. ACM Press, New York, pp 283–291
Sen P, Cammarano M, Hanrahan P (2003) Shadow silhouette maps. ACM Trans Graph 23(3):521–526
Stamminger M, Drettakis G (2002) Perspective shadow maps. ACM Trans Graph 21(3):557–562
Tadamura K, Qin X, Jiao G, Nakamae E (2001) Rendering optimal solar shadows using plural sunlight depth buffers. Vis Comput 17(2):76–90
Tanaka T, Takahashi T (1994) Cross scan buffer and its applications. Comput Graph Forum 13(3):467–476
Whitted T, Weimer DM (1981) A software test-bed for the development of 3d raster graphics systems. ACM Trans Graph 1(1):43–58
Williams L (1978) Casting curved shadows on curved surfaces. In: Proceedings of ACM SIGGRAPH 78, Computer Graphics. ACM Press, New York, pp 270–274
Woo A (1992) The shadow depth map revisited, graphics gems III. Academic
Author information
Authors and Affiliations
Corresponding author
Rights and permissions
About this article
Cite this article
Arvo, J., Hirvikorpi, M. Compressed shadow maps. Visual Comput 21, 125–138 (2005). https://doi.org/10.1007/s00371-004-0276-9
Published:
Issue Date:
DOI: https://doi.org/10.1007/s00371-004-0276-9