Abstract
This study introduces Soft Bilateral Filtering Shadows method of dynamic scenes, which uses multi-matrices of the light sample points due to lack realism in soft shadows generation in real time. While geometry-based shadow algorithm requires one pass per polygon for rendering shadow that requires time-consuming, the adopted shadow map algorithm needs a single rendering pass for each sample point of the light source to generate shadow at low cost. This method renders a complex scenes and accurately eliminating the inherent deficiencies in shadow maps. In order to compute shadow maps, view matrices were used for each sample point of the extended light source. Then penumbra region was used for interpolation based on bilateral filtering to create the soft shadows. They depend on multiple shadow maps which provide antialiasing shadow maps. The method uses fragment shader for rendering multiple shadow maps with penumbra and umbra regions. The main contribution of this article is introducing interpolation bilaterally of image-based shadows. This method makes the most effect of the computation significantly appear at the edges of the penumbra region. Furthermore, the filtering allows to obtain on the soft shadow marvelously at the lowest number possible of the light sample points. The generated soft shadows have good performance and high quality therefore, they are suitable for interactive applications.
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References
Aila T, Laine S (2004) Alias-free shadow maps. Rendering techniques, 2004, 15th
Arvo J (2007) Alias-free shadow maps using graphics hardware. J Graph GPU Game Tools 12(1):47–59
Arvo J, Hirvikorpi M, Tyystjärvi J. (2004) Approximate soft shadows win an image‐space flood‐fill algorithm. In: Computer graphics forum (Vol. 23, No. 3, pp. 271–279). Blackwell Publishing, Inc
Atty L, Holzschuch N, Lapierre M, Hasenfratz JM, Hansen C, Sillion FX (2006) Soft shadow maps: efficient sampling of light source visibility. In: Computer graphics forum (Vol. 25, No. 4, pp. 725–741). Blackwell Publishing Ltd
Cai XH, Jia YT, Wang X, Hu SM, Martin RR (2006) Rendering soft shadows using multilayered shadow fins. In: Computer graphics forum (Vol. 25, No. 1, pp. 15–28). Blackwell Publishing Ltd
Chan E, Durand F (2003) Rendering fake soft shadows with smoothies. In: Rendering Techniques (pp. 208–218)
Crow FC (1977) Shadow algorithms for computer graphics. In: Acm siggraph computer graphics (Vol. 11, No. 2, pp. 242–248). ACM
De Boer WH (2006) Smooth penumbra transitions with shadow maps. J Graph GPU Game Tools 11(2):59–71
Eisemann E, Décoret X (2006) Plausible image based soft shadows using occlusion textures. In: Computer graphics and image processing, 2006. SIBGRAPI’06. 19th Brazilian Symposium on (pp. 155–162). IEEE
Fernando R (2005) Percentage-closer soft shadows. In ACM SIGGRAPH 2005 sketches (p. 35). ACM
Guennebaud G, Barthe L, Paulin M (2006) Real-time soft shadow mapping by Backprojection. In: Rendering techniques (pp. 227–234)
Johnson GS, Mark WR, Burns CA (2004) The irregular z-buffer and its application to shadow mapping. Computer Science Department, University of Texas at Austin
Kolivand H, Sunar MS (2011) Shadow mapping or shadow volume? Int J New Comput Archit Appl 1(2):275–281
Kolivand H, Sunar M (2012) Real-time outdoor rendering using hybrid shadow maps. Int J Innov Comput Inf Control 8(10 B):7168–7184
Lauritzen A, McCool M (2008). Layered variance shadow maps. In: Proceedings of graphics interface 2008 (pp. 139–146). Canadian Information Processing Society
Lawlor OS (2006) Interpolation-friendly soft shadow maps. In: CGVR (pp. 111–117)
Lefohn AE, Sengupta S, Owens JD (2007) Resolution-matched shadow maps. ACM Trans Graph 26(4):20
Lili W, Jingchao Z, Zhe S (2010) Real-time approximate soft shadow rendering with bidirectional penumbra map. In Educational and Information Technology (ICEIT), 2010 International Conference on (Vol. 1, pp. V1-248). IEEE
Kolivand H, Sunar MS (2015) Anti-aliasing in image based shadow generation techniques: a comprehensive survey. Multimed Tools Appl 74:7461–7487
Reeves WT, Salesin DH, Cook RL (1987) Rendering antialiased shadows with depth maps. In: ACM Siggraph Computer Graphics (Vol. 21, No. 4, pp. 283–291). ACM
Tomasi C, Manduchi R (1998) Bilateral filtering for gray and color images. In: Computer Vision, 1998. Sixth International Conference on (pp. 839–846). IEEE
Wang L, Zhou S, Ke W, Popescu V (2014) GEARS: a general and efficient algorithm for rendering shadows. In: Computer graphics forum (Vol. 33, No. 6, pp. 264–275)
Williams L (1978) Casting curved shadows on curved surfaces. In ACM Siggraph Computer Graphics (Vol. 12, No. 3, pp. 270–274). ACM
Wimmer M, Scherzer D, Purgathofer W (2004) Light space perspective shadow maps. Rendering Techniques, 2004, 15th
Wyman C, Hansen CD (2003) Penumbra maps: approximate soft shadows in real-time. In: Rendering techniques (pp. 202–207)
Acknowledgments
This research was supported by Vot. Q.J130000.2528.12H18 RUG grant at MaGIC-X (Media and Games In-novation Centre of Excellence) UTM-IRDA Digital Media Centre Universiti Teknologi Malaysia 81310 Skudai Johor MALAYSIA.
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Ali, H.H., Kolivand, H. & Sunar, M.S. Soft bilateral filtering shadows using multiple image-based algorithms. Multimed Tools Appl 76, 2591–2608 (2017). https://doi.org/10.1007/s11042-016-3254-0
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DOI: https://doi.org/10.1007/s11042-016-3254-0