The Visual Computer

, Volume 26, Issue 12, pp 1497–1512 | Cite as

Layered occlusion map for soft shadow generation

Original Article

Abstract

This paper presents a high-quality high-performance algorithm to compute plausible soft shadows for complex dynamic scenes. Given a rectangular light source, the scene is rendered from the viewpoint placed at the center of the light source, and discretized into a layered depth map. For each scene point sampled in the depth map, the occlusion degree is computed, and stored in a layered occlusion map. When the scene is rendered from the camera’s viewpoint, the occlusion degree of a scene point is computed by filtering the layered occlusion map. The proposed algorithm produces soft shadows the quality of which is quite close to that of the ground truth reference. As it runs very fast, a scene with a million polygons can be rendered in real-time. The proposed method does not require pre-processing and is easy to implement in contemporary graphic hardware.

Keywords

Soft shadow algorithm Image processing Hardware accelerated rendering Real-time shadowing 

Preview

Unable to display preview. Download preview PDF.

Unable to display preview. Download preview PDF.

References

  1. 1.
    Agrawala, M., Ramamoorthi, R., Heirich, A., Moll, L.: Efficient image-based methods for rendering soft shadows. In: Proc. of SIGGRAPH’00, pp. 375–384 (2000) Google Scholar
  2. 2.
    Akenine-Möller, T., Assarsson, U.: Approximate soft shadows on arbitrary surfaces using penumbra wedges. In: Rendering Techniques, pp. 297–305 (2002) Google Scholar
  3. 3.
    Arvo, J., Hirvikorpi, M., Tyystjärvi, J.: Approximate soft shadows using image-space flood-fill algorithm. Comput. Graph. Forum 23(3), 271–280 (2004). (Proc. of Eurographics’04) CrossRefGoogle Scholar
  4. 4.
    Atty, L., Holzschuch, N., Lapierre, M., Hasenfratz, J.M., Hansen, C., Sillion, F.: Soft shadow maps: Efficient sampling of light source visibility. Comput. Graph. Forum 25(4) (2006) Google Scholar
  5. 5.
    Bavoil, L., Silva, C.T.: Real-time soft shadows with cone culling. In: Technical Sketches and Applications at SIGGRAPH’06 (2006) Google Scholar
  6. 6.
    Bavoil, L., Callahan, S.P., Silva, C.T.: Robust soft shadow mapping with backprojection and depth peeling. J. Graph. Tools 13(1), 19–30 (2008) Google Scholar
  7. 7.
    Crow, F.C.: Shadow algorithms for computer graphics. Comput. Graph. 11(2), 242–248 (1977). (Proc. of SIGGRAPH’77) CrossRefGoogle Scholar
  8. 8.
    Drettakis, G., Fiume, E.: A fast shadow algorithm for area light sources using backprojection. Comput. Graph. Forum 28, 223–230 (1994) Google Scholar
  9. 9.
    Eisemann, E., Décoret, X.: Occlusion textures for plausible soft shadows. Comput. Graph. Forum 27(1), 13–23 (2008) CrossRefGoogle Scholar
  10. 10.
    Everitt, C.: Interactive order-independent transparency. Tech. rep., NVIDIA Corporation (2001) Google Scholar
  11. 11.
    Fernando, R.: Percentage-closer soft shadows. In: ACM SIGGRAPH 2005 Sketches and Applications, p. 35 (2005) Google Scholar
  12. 12.
    Forest, V., Barthe, L., Paulin, M.: Accurate shadows by depth complexity sampling. Comput. Graph. Forum 27(2), 663–674 (2008). (Eurographics 2008 Proceedings) CrossRefGoogle Scholar
  13. 13.
    Forest, V., Barthe, L., Guennebaud, G., Paulin, M.: Soft textured shadow volume. Comput. Graph. Forum 28(4), 1111–1121 (2009). (Eurographics Symposium on Rendering 2009) CrossRefGoogle Scholar
  14. 14.
    Guennebaud, G., Barthe, L., Paulin, M.: Real-time soft shadow mapping by backprojection. In: Proc. of Eurographics Symposium on Rendering, pp. 227–234 (2006) Google Scholar
  15. 15.
    Guennebaud, G., Barthe, L., Paulin, M.: High quality adaptive soft shadow mapping. Comput. Graph. Forum 26(3) (2007). (Proc. of Eurographics’07) Google Scholar
  16. 16.
    Hasenfratz, J.M., Lapierre, M., Holzschuch, N., Sillion, F.: A survey of real-time soft shadows algorithms. Comput. Graph. Forum 22(4), 753–774 (2003) CrossRefGoogle Scholar
  17. 17.
    Heidrich, W., Brabec, S., Seidel, H.P.: Soft shadow maps for linear lights. In: Proc. of the 11th Eurographics Workshop on Rendering, pp. 269–280 (2000) Google Scholar
  18. 18.
    Iwasaki, K., Dobashi, Y., Yoshimoto, F., Nishita, T.: Precomputed radiance transfer for dynamic scenes taking into account light interreflection. In: Proc. of the Eurographics Symposium on Rendering, pp. 35–44 (2007) Google Scholar
  19. 19.
    Laine, S., Aila, T., Assarsson, U., Lehtinen, J., Akenine-Möller, T.: Soft shadow volumes for ray tracing. ACM Trans. Graph. 24(3), 1156–1165 (2005) CrossRefGoogle Scholar
  20. 20.
    Pan, M., Wang, R., Liu, X., Peng, Q., Bao, H.: Precomputed radiance transfer field for rendering interreflections in dynamic scenes. Comput. Graph. Forum 26(3), 485–493 (2007) CrossRefGoogle Scholar
  21. 21.
    Reeves, W.T., Salesin, D.H., Cook, R.L.: Rendering antialiased shadows with depth maps. Comput. Graph. 21(4), 283–291 (1987). (Proc. of SIGGRAPH’87) CrossRefGoogle Scholar
  22. 22.
    Rong, G., Tan, T.S.: Jump Flooding: An Efficient and Effective Communication Pattern for Use on GPUs, pp. 185–192. Charles River Media (2006). Chap. 3 Google Scholar
  23. 23.
    Schwarz, M., Stamminger, M.: Bitmask soft shadows. Comput. Graph. Forum 26(3) (2007). (Proc. of Eurographics’07) Google Scholar
  24. 24.
    Schwarz, M., Stamminger, M.: Microquad soft shadow mapping revisited. In: Eurographics’06 Short Paper (2008) Google Scholar
  25. 25.
    Schwarz, M., Stamminger, M.: Quality scalability of soft shadow mapping. In: Proc. of Graphics Interface’08 (2008) Google Scholar
  26. 26.
    Sintorn, E., Eisemann, E., Assarsson, U.: Sample-based visibility for soft shadows using alias-free shadow maps. Comput. Graph. Forum 27(4), 1285–1292 (2008). (Proc. of the Eurographics Symposium on Rendering 2008) CrossRefGoogle Scholar
  27. 27.
    Sloan, P.P.J., Kautz, J., Snyder, J.: Precomputed radiance transfer for real-time rendering in dynamic, low-frequency lighting environments. In: Proc. of SIGGRAPH’02, pp. 527–536 (2002) Google Scholar
  28. 28.
    Stamminger, M., Drettakis, G.: Perspective shadow maps. ACM Trans. Graph. 21(3), 557–562 (2002). (Proc. of SIGGRAPH 2002) CrossRefGoogle Scholar
  29. 29.
    Williams, L.: Casting curved shadows on curved surfaces. Comput. Graph. 12(3), 270–274 (1978). (Proc. of SIGGRAPH’78) CrossRefGoogle Scholar
  30. 30.
    Wimmer, M., Scherzer, D., Purgathofer, W.: Light space perspective shadow maps. In: Rendering Techniques 2004 (Proc. Eurographics Symposium on Rendering), pp. 143–151 (2004) Google Scholar
  31. 31.
    Woo, A., Poulin, P., Fournier, A.: A survey of shadow algorithms. IEEE Comput. Graph. Appl. 10(6), 13–32 (1990) CrossRefGoogle Scholar
  32. 32.
    Yang, B., Feng, J., Guennebaud, G., Liu, X.: Packet-based hierarchal soft shadow mapping. Comput. Graph. Forum 28(4), 1121–1130 (2009). (Proceedings of Eurographics Symposium on Rendering 2009) CrossRefGoogle Scholar
  33. 33.
    Zhou, K., Hu, Y., Lin, S., Guo, B., Shum, H.Y.: Precomputed shadow fields for dynamic scenes. ACM Trans. Graph. 24(3), 1196–1201 (2005) CrossRefGoogle Scholar

Copyright information

© Springer-Verlag 2010

Authors and Affiliations

  1. 1.Korea UniversitySeoulKorea

Personalised recommendations