Browse > Article
http://dx.doi.org/10.15701/kcgs.2017.23.3.55

A Soft Shadow Technique for a Real-time Mobile Ray Tracing Hardware  

Kwon, Hyuck-Joo (Department of Electrical and Electronic Engineering, Yonsei University)
Hong, Dukki (Department of Computer Engineering, Sejong University)
Park, Woo-Chan (Department of Computer Engineering, Sejong University)
Lee, Sanghoon (Department of Electrical and Electronic Engineering, Yonsei University)
Publication Information
Journal of the Korea Computer Graphics Society / v.23, no.3, 2017 , pp. 55-64 More about this Journal
Abstract
In this paper, a novel soft shadow method is suggested to support realistic shadows in mobile ray tracing. In ray tracing, soft shadow is generally generated by sampling a shadow ray. As this sampling method increases the number of rays to be processed, it has undermined the performance. We designed the proposed soft shadow processing method and hardware architecture to overcome this problem through selective shadow generation and triangle address caching for minimizing the performance degradation caused by sampling. The proposed hardware architecture can be integrated into a mobile ray-tracing hardware and was evaluated in terms of its performance on the FPGA. Based on the results, the rendering performance about 4, 8, and 16 samples were improved, respectively, by 40%, 50%, and 56% on average compared to the previous method, and it was found that the real-time soft shadow processing is feasible with the proposed hardware architecture.
Keywords
soft shadow; real-time mobile ray tracing; hardware architecture; FPGA implementation;
Citations & Related Records
연도 인용수 순위
  • Reference
1 N. Feltman, M. Lee, and K. Fatahalian, "Srdh: Specializing bvh construction and traversal order using representative shadow ray sets," in Proceedings of the ACM Conference on High Performance Graphics, 2012, pp. 49-55.
2 P. Djeu, S. Keely, and W. Hunt, "Accelerating shadow rays using volumetric occluders and modified kd-tree traversal," in Proceedings of the ACM Conference on High Performance Graphics, 2009, pp. 69-76.
3 J.-H. Nah and D. Manocha, "Sato: Surface area traversal order for shadow ray tracing," Computer Graphics Forum, vol. 33, no. 6, pp. 167-177, Sep. 2014.   DOI
4 W.-J. Lee, Y. Shin, J. Lee, J.-W. Kim, J.-H. Nah, S. Jung, S. Lee, H.-S. Park, and T.-D. Han, "Sgrt: A mobile gpu architecture for real-time ray tracing," in Proceedings of the ACM Conference on High Performance Graphics, 2013, pp. 109-119.
5 R. Overbeck, R. Ramamoorthi, and W. R. Mark, "Large ray packets for real-time whitted ray tracing," in Proceedings of the IEEE Symposium on Interactive Ray Tracing, 2008, pp.41-48.
6 A. Reshetov, "Faster ray packets-triangle intersection through vertex culling," in Proceedings of the IEEE Symposium on Interactive Ray Tracing, 2007, pp. 105-112.
7 S. Boulos, I.Wald, and P. Shirley, "Geometric and arithmetic culling methods for entire ray packets," Tech. Rep., 2006.
8 E. R. Freniere, G. G. Gregory, and R. A. Hassler, "Edge diffraction in monte carlo ray tracing," in Proceedings of the SPIE's International Symposium on Optical Science, 1999, pp. 151-157.
9 K. Komatsu, Y. Kaeriyama, K. Suzuki, H. Takizawa, and H. Kobayashi, "A fast ray prustum-triangle intersection algorithm with precomputation and early termination," IPSJ Online Transactions, vol. 1, pp. 1-11, Jul. 2008.   DOI
10 J. M. Hasenfratz, M. Lapierre, N. Holzschuch, and F. Sillion, "A survey of real-time soft shadows algorithms," Computer Graphics Forum, vol. 22, no. 4, pp. 753-774, Dec. 2003.   DOI
11 J.-H. Nah, H.-J. Kwon, D.-S. Kim, C.-H. Jeong, J. Park, T.-D. Han, D. Manocha, and W.-C. Park, "Raycore: A ray-tracing hardware architecture for mobile devices," ACM Transactions on Graphics, vol. 33, no. 5, p. 162, Aug. 2014.   DOI
12 T. Whitted, "An improved illumination model for shaded display," in Proceedings of the ACM SIGGRAPH Courses, 1979, p. 4.
13 R. L. Cook, T. Porter, and L. Carpenter, "Distributed ray tracing," in Proceedings of the ACM SIGGRAPH Computer Graphics, 1984, pp. 137-145.
14 S. Parker, W. Martin, P.-P. J. Sloan, P. Shirley, B. Smits, and C. Hansen, "Interactive ray tracing," in Proceedings of the ACM Symposium on Interactive 3D Graphics, 1999, pp. 119-126.
15 S. Boulos, D. Edwards, J. D. Lacewell, J. Kniss, J. Kautz, and P. Shirley, "Interactive distribution ray tracing," Tech. Rep., 2006.
16 S. Boulos, D. Edwards, J. D. Lacewell, J. Kniss, J. Kautz, P. Shirley, and I. Wald, "Packet-based whitted and distribution ray tracing," in Proceedings of the ACM Graphics Interface, 2007, pp. 177-184.
17 K. Garanzha and C. Loop, "Fast ray sorting and breadth-first packet traversal for gpu ray tracing," Computer Graphics Forum, vol. 29, no. 2, pp. 289-298, May 2010.   DOI
18 C. Benthin and I. Wald, "Efficient ray traced soft shadows using multi-frusta tracing," in Proceedings of the ACM Conference on High Performance Graphics, 2009, pp. 135-144.
19 T. Ize and C. Hansen, "Rtsah traversal order for occlusion rays," Computer Graphics Forum, vol. 30, no. 2, pp. 297-305, Apr. 2011.   DOI