Abstract
Reproducing correct soft shadows in interactive applications is accomplished by gathering multiple samples of the area light source. The size of the penumbra region is unpredictable, so the required sample density should be high to ensure soft shadow transitions in all configurations of the area light size. Therefore, multiple shadow maps must be evaluated for each scene configuration, which leads to performance degradation. To tackle the challenge, we propose a novel technique based on the multisampling depth, which approximates soft shadows for large, fully dynamic scenes at interactive frame rates. Our algorithm can perform multiple depth tests for each pixel in the shadow map. We effectively reduce the number of samples of zone light to avoid other rendering passes. We reuse shadow maps for other light source sampling setups without performing additional scene rendering while maintaining real-time performance. Our approach fits well in existing rendering pipelines and improves the robustness of many different soft shadow techniques.
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The datasets analyzed during the current study are available from the corresponding author on reasonable request.
References
Eisemann E, Schwarz M, Assarsson U, Wimmer M (2012) Real-time shadows. In: Peters, A.K. (ed.), 1st (edn.). CRC Press, New York (2012). ISBN: 9780429104695. https://doi.org/10.1201/b11030
Williams L.: Casting curved shadows on curved surfaces. In: Proceedings of the 5th Annual Conference on Computer Graphics and Interactive Techniques, Association for Computing Machinery, SIGGRAPH’78, vol. 12, No. 3, pp. 270–274, New York (1978). ISBN: 9781450379083. https://doi.org/10.1145/800248.807402
Crow Franklin C.: Shadow algorithms for computer graphics. In: Proceedings of the 4th Annual Conference on Computer Graphics and Interactive Techniques, SIGGRAPH’77. ACM Press, pp. 242–248 (1977). https://doi.org/10.1145/965141.563901
Slater, M.A.: A comparison of three shadow volume algorithms. J. Vis. Comput. 9(1), 25–38 (1992). https://doi.org/10.1007/BF01901026
Pagot, C.A., Comba, J.L.D., de Oliveira Neto, M.M.: Multiple-depth shadow maps. In: Proceedings of: XVII Brazilian Symposium on Computer Graphics and Image Processing, (SIBGRAPI 2004) 17–20 October 2004, Curitiba (2004). https://doi.org/10.1109/SIBGRA.2004.1352975
Ali, H.H., Kolivand, H., Sunar, M.S.: Soft bilateral filtering shadows using multiple image-based algorithms. J. Multimed. Tools Appl. 76(2), 2591–2608 (2017). https://doi.org/10.1007/s11042-016-3254-0
Schwärzler, M., Mattausch, O., Scherzer, D., Wimmer, M.: Fast accurate soft shadows with adaptive light source sampling. In: Proceedings of the 17th International Workshop on Vision, Modeling, and Visualization (VMV 2012), pp. 39–46. https://doi.org/10.2312/PE/VMV/VMV12/039-046
Randima, F.: Percentage-closer soft shadows. In: Association for Computing Machinery, SIGGRAPH’05 Sketches, pp. 35-es, New York (2005). ISBN: 9781450378277. https://doi.org/10.1145/1187112.1187153.
Hasenfratz, J.M., Lapierre, M., Holzschuch, N., Sillion, F.X.: A survey of real-time soft shadows algorithms. Comput. Gr. Forum 22(4), 753–774 (2003). https://doi.org/10.1111/j.1467-8659.2003.00722.x
Reeves William, T., Salesin David, H., Cook Robert, L.: Rendering antialiased shadows with depth maps. In: Proceedings of the 14th Annual Conference on Computer Graphics and Interactive Techniques, SIGGRAPH’87, Association for Computing Machinery, vol. 21, No. 4, pp. 283–291, New York (1987). ISBN: 0897912276. https://doi.org/10.1145/37401.37435
Donnelly, W., Lauritzen, A.: Variance shadow maps. In: Proceedings of the 2006 Symposium on Interactive 3D Graphics and Games, I3D’06, pp. 161–165, New York (2006). ISBN: 159593295X. https://doi.org/10.1145/1111411.1111440
Annen, T., Mertens, T., Bekaert, P., Seidel, H.-P., Kautz, J.: Convolution shadow maps. In: Kautz J., Pattanaik S., (eds.) EGSR’07 Proceedings of the 18th Eurographics Conference on Rendering Techniques (Grenoble, France), vol. 18, pp. 51–60, Eurographics (2007). https://doi.org/10.2312/EGWR/EGSR07/051-060
Zhang, F., Sun, H., Xu, L., Lun, L.K.: Parallel-split shadow maps for large-scale virtual environments. In: Proceedings of the 2006 ACM International Conference on Virtual Reality Continuum and Its Applications, Association for Computing Machinery, VRCIA’06, pp. 311–318, New York (2006). https://doi.org/10.1145/1128923.1128975
Gaël, G., Loïc, B., Mathias, P.: Real-time soft shadow mapping by backprojection. In: Proceedings of the 17th Eurographics Conference on Rendering Techniques, Eurographics Symposium on Rendering, pp. 227–234 (2006). ISBN: 3905673355. https://doi.org/10.2312/EGWR/EGSR06/227-234
Barthe, G.G.L., Paulin, M.: High-quality adaptive soft shadow mapping. In: Computer Graphics Forum, Eurographics 2007 Proceedings, vol. 26, No. 3, pp. 525–534 (2007). https://doi.org/10.1111/j.1467-8659.2007.01075.x
Atty, L., Holzschuch, N., Lapierre, M., Hasenfratz, J.-M., Sillion, F.X., Charles, H.: Soft shadow maps: efficient sampling of light source visibility. Comput. Gr. Forum. 25(4), 725–741 (2006). https://doi.org/10.1111/j.1467-8659.2006.00995.x
Aszódi, B., Szirmay-Kalos, L.: Real-time soft shadows with shadow accumulation. In: Eurographics 2006 Short Presentations, pp. 53–56 (2006). https://doi.org/10.2312/egs.20061026
Schwarz, M., Stamminger, M.: Bitmask soft shadows. In: Proceedings of Eurographics 2007, Computer Graphics Forum, vol. 26, No. 3, pp. 515–524 (2007). Doi: https://doi.org/10.1111/j.1467-8659.2007.01074.x.
Buades, J.M., Gumbau, J., Chover, M.: Separable soft shadow mapping. Vis. Comput. Int. J. Comput. Gr. 32(2), 167–178 (2016). https://doi.org/10.1007/s00371-015-1062-6
Xu, Z., Li, B., Cai, X., Sun, H., Zhang, Y.: Generate accurate soft shadows using complete occluder buffer. In: Computer-Aided Design and Computer Graphics (CAD/Graphics), 2015 14th International Conference, IEEE Xplore, pp. 97–104 (2015). https://doi.org/10.1109/CADGRAPHICS.2015.35.
Liktor, G., Spassov, S., Muckl, G., Dachsbacher, C.: Stochastic soft shadow mapping. J Comput Gr Forum 34(4), 1–11 (2015). https://doi.org/10.1111/cgf.12673
Heckbert, P.S., Herf, M.: Simulating soft shadows with graphics hardware. Technical Report CMU-CS-97-104, Computer Science Department, Carnegie Mellon University (1997)
Agrawala, M., Ramamoorthi, R., Heirich, A., Moll, L.: Efficient image-based methods for rendering soft shadows. In: Proceedings of the 27th Annual Conference on Computer Graphics and Interactive Techniques, pp. 375–384 (2000). https://doi.org/10.1145/344779.344954
St-Amour, J.-F., Paquette, E., Poulin, P.: Soft shadows from extended light sources with penumbra deep shadow maps. In: GI’05 Proceedings of Graphics Interface 2005, pp. 105–112 (2005). ISBN: 1-56881-265-5. Doi: https://doi.org/10.5555/1089508.1089526
Scherzer, D., Schwärzler, M., Mattausch, O., Wimmer, M.: Real-time soft shadows using temporal coherence. In: Advances in Visual Computing: 5th International Symposium on Visual Computing, (ISVC 2009) (2009), Lecture Notes in Computer Science, Springer, pp. 13–24. https://doi.org/10.1007/978-3-642-10520-3_2
Bartz, D., Meißner, M., Hüttner, T.: Extending graphics hardware for occlusion queries in OpenGL. In: Proceedings of the ACM SIGGRAPH/EUROGRAPHICS Workshop on Graphics hardware (New York, NY, USA, 1998), HWWS’98, ACM, pp. 97–103. https://doi.org/10.2312/EGGH/EGGH98/097-103
Kajiya, J.T.: The rendering equation. In: Proceedings of the 13th Annual Conference on Computer Graphics and Interactive Techniques, ACM, vol. 20, pp. 143–150 (1986). https://doi.org/10.1145/15922.15902
Pagot, C.A., Comba, J.D., De Oliveira Neto, M.M.: Multiple-depth shadow maps. In: Proceedings of the IEEE 17th Barzilian Symposium Computer Graphics and Image, pp. 308–315 (2004). https://doi.org/10.1109/SIBGRA.2004.1352975
Engel, W., Cascaded Shadow Maps: Book, ShaderX5: advanced rendering techniques, In: Charles River Media; Har/Cdr (edn.), pp. 197–206 (2007), ISBN: 978-1584504993
Veach, E.: Robust Monte Carlo methods for light transport simulation. Ph.D. Thesis. Stanford University (1997). ISBN: 0-591-90780-1
Phong, B.: Illumination for computer generated images. Commun. ACM 18(6), 311–317 (1975). https://doi.org/10.5555/906584
Willmott, C.J., Matsuura, K.: Advantages of the Mean Absolute Error (MAE) over the Root Mean Square Error (RMSE) in assessing average model performance. In: Climate Research, vol. 30, pp. 79–82 (2005). https://doi.org/10.3354/cr030079
Wang, Z., Bovik, A.C., Sheikh, H.R., Simoncelli, E.P.: Image quality assessment: from error visibility to structuralsimilarity. IEEE Trans. Image Process. 13(4), 600–612 (2004). https://doi.org/10.1109/TIP.2003.819861
Stanford University: The Stanford 3D Scanning Repository (1996). http://graphics.stanford.edu/data/3Dscanrep/
Morgan McGuire. Computer Graphics Archive (2017). http://casualeffects.com/data/index.html
Sketchfab Community: To publish and find 3D content online, Paris, France (2012). https://sketchfab.com/feed
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Zerari, A.E.M., Meadi, M.N. & Babahenini, M.C. Multisampling-depth soft shadow based on cascaded area light source. Vis Comput 40, 1339–1357 (2024). https://doi.org/10.1007/s00371-023-02852-8
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DOI: https://doi.org/10.1007/s00371-023-02852-8