基于光子映射的虚拟现实真实感渲染算法研究
|
摘要
真实感渲染是计算机图形学一直以来的追求目标,本文在全面综述目前工作的基础上,从阴影生成、焦敞效果渲染和并行化等角度出发进行真实感渲染算法的研究,实现了不同方面的优化渲染算法,并给出了详绌的实验结果。
本文以光子映射算法为基础,研究光子映射算法的光子搜索加速、焦散光子图优化以及并行化等问题,尝试将真实感全局光照渲染算法的概念应用于虚拟现实的实时渲染算法中,以提高虚拟现实的真实感。主要工作集中于以下几点:
1.在阴影生成方面,提出基于投影距离的阴影图算法,对传统软阴影生成算法的视觉效果进行了改进,使得软阴影的模糊程度和阴影的投影距离相关,在保证渲染效率的基础上得到了视觉上更加真实的阴影效果。为了实现物理上更加真实的光照,在光子映射思想的基础上提出了光子纹理的概念,在纹理空间进行相邻光子的搜索和光照计算,从而加快光子映射算法的采样点辐射评估过程。
2.针对真实感渲染中的焦散渲染问题,在光子映射算法的基础上提出了光子聚类的算法,目的是在保证渲染质量的前提下,尽可能的减少渲染焦散所需要的光子投射量,提出了一种在渲染速度和渲染精确度之间寻求折中的途径。
3.针对光子映射算法的渲染效率问题,实现了共享内存多处理机上的并行化光子映射算法,并获得了令人满意的加速比。对不同任务分配方案进行了对比,初步地研究了光子映射并行计算中的任务分配、负载平衡等问题。
Realistic rendering is always an important object of computer graphics. Based on current research, shadow generation, caustic and parallelized rendering are studied, several optimized algorithms are realized and particular experiments results are given.
Based on photon mapping, accelerating of photons searching, optimize of caustic photon map and parallelization are emphasized. The concepts of realistic rendering are applied in real-time rendering of VR, in order to improve the performance of visual realistic. The main work of this dissertation is concentrated in following three aspects:
1. In shadow generation, the shadow map algorithm is optimized based on projection distance, so the visual effects of traditional algorithm is improved. The blur degree and the light degree are related to the distance between the shadow and the object which cast it. Much more realistic shadow result can be generated while the rendering efficiency is kept. In order to generate the realistic shadow in nature, the concept of photon texture is proposed based on photon mapping algorithm. In photon texture algorithm, the photon collection process is completed in texture, so the rendering speed can be increased remarkably.
2. In caustic rendering, photon clustering algorithm is proposed based on photon mapping, intending to decrease the caustic photons while the rendering quality can be maintained. In another word, photon clustering is a method to compromise the rendering quality and speed when doing the caustic rendering.
3. Aim at the efficiency of graphics rendering, a parallelized photon mapping algorithm is realized on the share memory multi-processor cluster and satisfying speed-up can be achieved. Different assignment plans are compared and pilot studied.
本文以光子映射算法为基础,研究光子映射算法的光子搜索加速、焦散光子图优化以及并行化等问题,尝试将真实感全局光照渲染算法的概念应用于虚拟现实的实时渲染算法中,以提高虚拟现实的真实感。主要工作集中于以下几点:
1.在阴影生成方面,提出基于投影距离的阴影图算法,对传统软阴影生成算法的视觉效果进行了改进,使得软阴影的模糊程度和阴影的投影距离相关,在保证渲染效率的基础上得到了视觉上更加真实的阴影效果。为了实现物理上更加真实的光照,在光子映射思想的基础上提出了光子纹理的概念,在纹理空间进行相邻光子的搜索和光照计算,从而加快光子映射算法的采样点辐射评估过程。
2.针对真实感渲染中的焦散渲染问题,在光子映射算法的基础上提出了光子聚类的算法,目的是在保证渲染质量的前提下,尽可能的减少渲染焦散所需要的光子投射量,提出了一种在渲染速度和渲染精确度之间寻求折中的途径。
3.针对光子映射算法的渲染效率问题,实现了共享内存多处理机上的并行化光子映射算法,并获得了令人满意的加速比。对不同任务分配方案进行了对比,初步地研究了光子映射并行计算中的任务分配、负载平衡等问题。
Realistic rendering is always an important object of computer graphics. Based on current research, shadow generation, caustic and parallelized rendering are studied, several optimized algorithms are realized and particular experiments results are given.
Based on photon mapping, accelerating of photons searching, optimize of caustic photon map and parallelization are emphasized. The concepts of realistic rendering are applied in real-time rendering of VR, in order to improve the performance of visual realistic. The main work of this dissertation is concentrated in following three aspects:
1. In shadow generation, the shadow map algorithm is optimized based on projection distance, so the visual effects of traditional algorithm is improved. The blur degree and the light degree are related to the distance between the shadow and the object which cast it. Much more realistic shadow result can be generated while the rendering efficiency is kept. In order to generate the realistic shadow in nature, the concept of photon texture is proposed based on photon mapping algorithm. In photon texture algorithm, the photon collection process is completed in texture, so the rendering speed can be increased remarkably.
2. In caustic rendering, photon clustering algorithm is proposed based on photon mapping, intending to decrease the caustic photons while the rendering quality can be maintained. In another word, photon clustering is a method to compromise the rendering quality and speed when doing the caustic rendering.
3. Aim at the efficiency of graphics rendering, a parallelized photon mapping algorithm is realized on the share memory multi-processor cluster and satisfying speed-up can be achieved. Different assignment plans are compared and pilot studied.
引文
[1]彭群生,鲍虎军.光照明模型与真实感图形生成技术.科学(上海).1997.49(2):11-13.
[2]Turne:Whitted.An improved illumination model for shaded display.Communications of the ACM.1980.23(6):343-349.
[3]Robert L.Cook.Stochastic sampling in computer graphics.ACM Transactions on Graphics.1986.5(1):51-72.
[4]Robert L.Cook,Thomas Porter and Loren Carpenter.Distributed ray tracing.Computer Graphics.1984.18(3):137-145.
[5]Peter Shirley.Physically Based Lighting Calculations for Computer Graphics.Ph.D.thesis.Dept of Computer Science.U.of Illinois,Urbana Champaign.1990.
[6]Eric P.Lafortune,Yves D.Willems.A 5D tree to reduce the variance of Monte Carlo ray tracing.In Eurographics Rendering Workshop.1995.11-20.
[7]Henrik Warm Jensen.Importance driven path tracing using the photon map.In Eurographics Rendering Workshop 1995.326-335.
[8]Eric P.Lafortune.Mathematical Models and Monte Carlo Algorithms for Physically Based Rendering.PhD thesis.University of Leuven.1996.
[9]Eric P.Lafortune and Yves D.Willems.Bidirectional path tracing.In Compugraphics93'.1993.95-104.
[10]Appel,A.Some techniques for shading machine renderings of solids.AFIPS 1968 Spring Joint Computer Conf.1968.32:37-45.
[11]Arvo,J.Transfer equations in global illumination.Global illumination,SIGGRAPH 93Course Notes.1993.42:23-9.
[12]Fujimoto A,Tanaka T,Iwata K.ARTS:Accelerated ray t racing system.IEEE Computer Graphics and Applications.1986.6(4):16-26.
[13]Rubin S,Whitted T.A three dimensional representation for fast rendering of complex scenes.Computer Graphics.1980.14(3):110-116.
[14]Glassner A S.Space subdivision for fast ray t racing.IEEE Computer Graphics and Applications.1984.4(10):15-22.
[15]Reshetov A,Soupikov A,Hurley J.Multi-level ray tracing algorithm.ACM Transactions on Graphics,2005,24(3):1176-1185.
[16]Wald I,Slusallek P,Bent hin C,Wagner M.Interactive rendering wit h coherent ray tracing.Proceedings of the EUROGRAPHICS 2001.Los Angeles,California.2001.20(3):153-164.
[17]Wald I,Lze T,Kensler A,Knoll A,Parker S G.Ray tracing animated scenes using coherent grid traversal.ACM Transactions on Graphics.2006.25(3):485-493.
[18]Carr N A,Hoberock J,Crane K,Hart J C.Fast GPU ray tracing of dynamic meshes using geometry images.Proceedings of the Graphics Interface 2006.Quebec,Canada.2006:203-209.
[19]陈为,彭群生,鲍虎军.视点相关的层次采样:一种硬件加速体光线投射算法.软件学报.2006.17(3).587-601.
[20]黄沛杰,王文成等.基于中介面加快光线跟踪计算.计算机学报.2007.30(2):262-271.
[21]苗兰芳,黄劲,郑文庭,鲍虎军,彭群生.点模型的局部几何重建和光线跟踪.计算机辅助设计与图形学学报.2006.18(6).805-811.
[22] Cindy M. Goral, Kenneth E. Torrance,etc. Modeling the interaction of light between diffuse surfaces. Computer Graphics. 1984.18(3):212-222.
[23] Michael F. Cohen, Donald P. Greenberg. The Hemi-Cube: A radiosity solution for complex environments. Computer Graphics. 1985.19(3):31-40.
[24] David S. Immel, Michael F. Cohen, Donald P. Greenberg. A radiosity method for non-diffuse environments. Computer Graphics.l986.20(4):133-142.
[25] John R. Wallace, Michael F. Cohen, Donald P. Greenberg. A two-pass solution to the rendering equation: A synthesis of ray tracing and radiosity methods. Computer Graphics.l987.21(4):311-320.
[26] Brian Smits,James Arvo, David Salesin. An importance driven radiosity algorithm. Computer Graphics. 1992.26(2):273-282.
[27]Brian Smits,James Arvo, Donald Greenberg. A clustering algorithm for radiosity in complex environments. In proceedings of SIGGRAPH. 1994.435-442.
[28] Pat Hanrahan, David Salzman, Larry Aupperle. A rapid hierarchical radiosity algorithm. Computer Graphics. 1991.25(4): 197-206.
[29] Daniel Lischinski,Filippo Tampieri,Donald Greenberg. Discontinuity meshing for accurate radiosity. IEEE Computer Graphics and Applications.1992.12(6):25-39.
[30] C .M.Goral,K .E.Torrance,D ,P.Greenberg,B .Bataile. Modeling the Interaction of Light between Diffuse Surfaces.Computer Graphics. 1984.18(3).213-222.
[31] T. Nishita,E. Nakamae,Continuous Tone Representation of Three-Dimensional Objects Taking Account of Shadows and Inter-reflection.Computer Graphics.l985.19(3).23-30.
[32] F. Sillion,C .Puech,A General Two-pass Method Integrating Specular and Diffuse Reflection,Computer Graphics. 1989.23(3).335-344.
[33] J. T.Kajiya. The Rendering Equation. Computer Graphics. 1986.20(4). 143-150.
[34] S. N .Pattanaik and S.P.Muder.Computation of global illumination by Monte Carlo simulation of particle model of light.In proceedings of the Third Eurographics Workshop on Rendering. Bristol,U K. 1992.71-83.
[35] R.F.Tobler,M. Feda,W. Purgathofer,A.Wilkie. A Hierarchical Subdivision Algorithm for Stochastic Radiosity Methods.In Proceedings of the Eighth Eurographics Workshop on Rendering, France, 1997.193-203.
[36] P.Bekaert,L.N eumann,A.Neumann,M.Sbert,Y.D.Willems.Hierarchical MonteCarlo Radiosity.In Rendering Techniques'98(Proceedings of Eurographics Rendering Workshop'98),NewYork. 1998.259-268.
[37] J. Pope, A.Chalmers. Improving Hierarchical Monte Carlo Radiosity Algorithms.In The 8-th Intenrational Conference in Central Europe on Computer Graphics,Visualization and Interactive Digital Media.University of West Bohemia. 2000.244-251.
[38] F. Perez. Ignacio Martin and Xavier Pueyo:Hierarchical Monte Carlo Radiosity for General Environments.Technical Report II.Spain.2002.
[39] D.S.Immel,M.F.Cohen,D.P.Greenberg. A Radiosity Method for Non-diffuse Environments. Computer Graphics.l986.20(4).133-142.
[40] P. Hanrahan,D.Salzman,L.Upperle. A Rapid Hierarchical Radiosity Algorithm. Computer Graphics. 1991.25(4): 197-206.
[41] Henrik Wann Jensen. High Quality Rendering using Ray Tracing and Photon Mapping. Siggraph 2007.Course8.
[42]Henrik Wann Jensen.Global illumination using photon maps.Eurographics Rendering Workshop 1996,21-30.
[43]Henrik Wann Jensen,Per H.Christensen.Efficient simulation of light transport in scenes with participating media using photon maps.In Computer Graphics(ACM SIGGRAPH 98Proceedings).1998.311-320.
[44]Yanyun Chen,Xin Tong,Jiaping Wang.Shell Texture Functions.ACM Transactions on Graphics.2004.23(3):343-353.
[45]Oscar Anson,Veronica Sundstedt,Diego Gutierrez,Alan Chalmers.Efficient selective rendering of participating media.ACM International Conference Proceeding Series.2006.153:135-142.
[46]Timothy Purcell,Craig Donner,Mike Cammarano,Henrik Wann Jensen.Photon Mapping on Programmable Graphics Hardware.Proceedings of the ACM SIGGRAPH/EUROGRAPHICS conference on Graphics hardware.2003.41-50.
[47]Per H.Christensen.Faster photon map global illumination.Journal of Graphics Tools.2000.4(3):1-10.
[48]Vincent C.H.Ma,Michael D.McCool.Low latency photon mapping using block hashing.Proceedings of the ACM SIGGRAPH conference on Graphics hardware.2002.89-99.
[49]邹湘军,孙健等.虚拟现实技术的演变发展与展望.系统仿真学报.2004.16(9):1905-1909.
[50]Henry Baumgartener.Link Flight Trainer is designated a historic mechanical engineering landmark,http://www.asmenews.org/archives/backissues/aug00/features/link.html.2008.1.
[51]鲍虎军.虚拟现实技术概论.中国基础科学.2003.3:26-32.
[52]Warren Robinett.Virtual Environment Workstation.http://www.warrenrobinett.com.2008,1.
[53]Fisher,Scott S.,James Humphries,Michael McGreevy,Warren Robinett.The Virtual Environment Display System.ACM Workshop on Interactive 3D Graphics,1986.
[54]J.D.Foley.Interfaces for Advanced Computing.Scientific American,1987,257(4):127-135.
[55]Burdea,G.and P.Coiffet.Virtual Reality Technology.New York,USA:John Wiley & Sons,1994.
[56]黄雷,李军义,张鑫,彭群生.双层介质光线散射效果的实时绘制.计算机辅助殴计与图形学学报.2007.19(11):1423-1428.
[57]王长波,王章野,周麒,彭群生.海市蜃楼现象的真实感绘制.计算机学报.2006.29(12):2080-2085.
[58]方建文,于金辉,姚(王争),彭韧.利用GPU对3D角色模型绘制水墨效果.计算机辅助设计与图形学学报.2007.19(4):415-418.
[59]宋成芳,谈奇峰,张龙,龚怿,陈为,彭群生.风场作用下的动态森林场景的实时仿真.计算机辅助设计与图形学学报.2007.19(3):323-328.
[60]陈越强,冯玉瑜,邓建松.有理B样条曲面的区间隐式化.计算机辅助设计与图形学学报.2007.19(7):849-853,860.
[61]曹卫群,鲍虎军.基于隐函数插值的连续多分辩率模型.软件学报.2000.11(9):1248-1256.
[62]Yokokohji Y,Hollis R L,Kanade T.What you can see is what you can feel.Proc.of the IEEE Annual International Symposium on Virtual Reality.1996.46-53.
[63]Khatib O,Brock O,Chang K,et al.Robotics & interactive simulation.Communication of the ACM.2002.45(3):46-51.
[64]Machado L S,Mello A N,Lopes R D,et al.A virtual reality simulator for bone marrow harvest for pediatric transplant.Studies in Health Technology and Informatics.2001.81:293-297.
[65]Popescu V G,Burdea G C,BouzitM,et al.A virtual reality based telerehabilitation system with force feedback.IEEE Trans on Information Technology in Biomedicine.2000.4(1):45-51.
[66]Kthnapfel U,Kuhn C,HübnerM,et al.Endoscopic surgery trainer as an example for virtual reality in medical education,http://iregt1.iai.fzk.de/KISMET/docs/UKMITAT.html,2008.
[67]Williams R,Srivastava M,Conatser J.Implementation and evaluation of a haptic playback system,http://www.hapticse.org.2008.
[68]Jayaram S,Wang Y,Jayaram U,et al.A virtual assembly design environment.Proc.of IEEE Conference on Virtual Reality.1999:172-179.
[69]王修晖,华炜,鲍虎军.面向多投影显示墙的手势交互系统设计与实现.计算机辅助设计与图形学学报.2007.19(3):318-322,328.
[70]H.Noser,C.Stem,P.Stucki.Distributed Virtual Reality environments based on rewriting systems.IEEE transactions on Visualization and Computer Graphics.2003.9(2):213-225.
[71]赵沁平,沈旭昆等.DVENET:一个分布式虚拟环境.计算机研究与发展.1998.35(12):1064-1068.
[72]何红梅,于兆其,陈小武.DVENET应用程序框架的设计与实现.计算机研究与发展,1998,35(12):1069-1072.
[73]赵沁平,沈旭昆,吴威等.分布式虚拟环境DVENET研究进展.系统仿真学报,2000,12(7):291-295.
[74]廖祝华,刘晓平.EAST装配仿真的三维交互和用户界面设计.系统仿真学报.2004,16(10):2329-2331.
[75]杨克俭,刘舒燕等.虚拟现实与城市规划.系统仿真学报,2000,12(3):207-209.
[76]陈皓,刘晓平.基于模板的虚拟现实平台,系统仿真学报,2006.18(12):3434-3437.
[77]吕耀怀.虚拟技术在道德教育中的运用.系统仿真学报,2002.14(1):110-111.
[78]刘列明,吴恩华.一种基于点光源的三维阴影的实时生成算法.软件学报.2000.11(6):785-790.
[79]吴恩华,柳有权.基于图形处理器(GPU)的通用计算.计算机辅助设计与图形学学报.2004,16(5):601-612.
[80]Williams,L.Casting curved shadows on curved surfaces.In Proc.SIGGRAPH,1978.12:270-274.
[81]Fernando R,Fernandez S,Bala K,et al.Adaptive Shadow Maps.Proceedings of Siggraph 2001.Los Angeles:Acm Siggraph.2001:387-390.
[82]Hasenfratz J M,Lapierre M,Holzschuchn,et al.A Survey of Real-Time Soft Shadow's Algorithms.Computer Graphics Forum.2003,22(4):753-774.
[83]LAINE S,AILA T,ASSARSSON U,et al.Soft shadow volumes for ray tracing.ACM Trans Graph.2005,24(3):1156-1165.
[84]周国民,卢涤非,张其前.一种梯形结构的软阴影锥生成方法.浙江大学学报.2007.34(6):628-632.
[85]王长波,谢步瀛,彭群生.建筑物阴影的实时模拟.武汉大学学报:工学版.2006.39(4):120-126,146.
[86]Reeves,W.,Salesin,D.,Cook,R.Rendering antialiased shadows with depth maps.In Proc.SIGGRAPH.1987.21(4):283-291.
[87]Williams D.,Andrew L.Variance Shadow Maps.Proceedings of the 2006 Symposium On Interactive 3D Graphics and Games.2006.
[88]Kirsch F,Doellner J.Real-Time soft shadows using a single light sample.Journal of Winter School on Computer Graphics.2003.11(1):255-262.
[89]Peter-Pike Sloan,Jan Kautz,John Snyder.Precomputed Radiance Transfer for Real-Time Rendering in Dynamic,Low-Frequency Lighting Environments.ACM Transactions on Graphics 2002.21(3):527-536.
[90]王京,王莉莉,李帅.一种基于GPU的预计算辐射度传递全频阴影算法.计算机研究与发展,2006.,43(9):1505-1510.
[91]Anders Wang Kristensen,Tomas Akenine-Moller,Hem'ik Wann Jensen.Precomputed Local Radiance Transfer for Real-Time Lighting Design.ACM SIGGRAPH.2005.1208-1215.
[92]Tomas M611er,Ben Trumbore.Fast,minimum storage ray-triangle intersection.Journal of Graphics Tools.1997.2(1):21-28.
[93]S Molnar.A sorting classification of parallel rendering.IEEE Computer Graphics And Applications.1994.14(4):23-32.
[94]R Samanta et al.Load balancing for multi-projector rendering systems.Proceedings of the SIGGRAPH/Eurographics Workshop on Graphics Hardware,Los Angeles,CA,Auguest 1999:107-116.
[95]G Humphreys,M Eldridge et al.WireGL:a scalable graphics system for clusters.Computer Graphics Proceedings,Annual Conference Series,ACM SIGGRAPH,Los Angeles,Califomia 2001:129-140.
[96]Jian Yang,Jiaoying Shi,Zhefan Jin,Hui Zhang.Design and implementation of a large-scale hybrid distributed graphics system.Eurographics Workshop on Parallel Graphics and Visualization.Saarbruecken,Germany.2002:39-49.
[97]金哲凡,杨建,石教英.分布式并行绘制系统中几何指令流压缩的研究与实现.计算机辅助设计与图形学学报.2002.14(9):824-828.
[98]石教英,林海,金哲凡.数据分布型sort-first并行图形绘制系统的研究与实现.计算机研究与发展.2004.41(2):376-382.
[99]王炜,徐玮,崔忠辉.宽广视野虚拟环境漫游的设计与实现.计算机工程与设计.2007.28(9):2107-2110.
[100]季华,陈福民.带负载平衡策略的PC sort-first并行渲染系统.计算机仿真.2005.22(11):209-214.
[101]孙亚萍,陈福民.分布式渲染中动态任务划分算法的研究.微计算机应用.2007.28(1):43-46.
[102]季华,王永强,陈福民.基于PC集群的sort-first并行渲染系统负载平衡研究.微计算机应用.2007.28(8):859-862.
[103]William Gropp,Ewing Lusk,Anthony Skjellum.Using MPI:portable parallel programming with the message-passing interface Cambridge,Mass.MIT Press,1999.
[104]Erik Reinhard,Alan Chalmers,Frederik W.Jansen.Hybrid Scheduling for Parallel Rendering using Coherent Ray Tasks.Proceedings of the 1999 IEEE symposium on Parallel visualization and graphics.1999.21-28.
[105]李亚峰,秦开怀.基于光学映射虚物体的并行绘制.中国图象图形学报,2003.8(12):1432-1437.
[106]刘晓平,余烨等.一种协同渲染环境下的场景管理策略,系统仿真学报.2007.19(1):85-88.
[107]翟磊,贝佳等.一种可扩展的远程渲染体系结构研究.系统仿真学报.2006.18(4):1081-1083.
[108]Wen-yuan Liu,Chun-jing Xiao,et al.Study on combining subtractive clustering with fuzzy c-means clustering.Proceedings of the Second International Conference on Machine Learning and Cybernetics.2003.2659-2662.
[109]陈燕.对两个经典聚类算法的分析.现代电子技术.2007.17(256):174-176.
[2]Turne:Whitted.An improved illumination model for shaded display.Communications of the ACM.1980.23(6):343-349.
[3]Robert L.Cook.Stochastic sampling in computer graphics.ACM Transactions on Graphics.1986.5(1):51-72.
[4]Robert L.Cook,Thomas Porter and Loren Carpenter.Distributed ray tracing.Computer Graphics.1984.18(3):137-145.
[5]Peter Shirley.Physically Based Lighting Calculations for Computer Graphics.Ph.D.thesis.Dept of Computer Science.U.of Illinois,Urbana Champaign.1990.
[6]Eric P.Lafortune,Yves D.Willems.A 5D tree to reduce the variance of Monte Carlo ray tracing.In Eurographics Rendering Workshop.1995.11-20.
[7]Henrik Warm Jensen.Importance driven path tracing using the photon map.In Eurographics Rendering Workshop 1995.326-335.
[8]Eric P.Lafortune.Mathematical Models and Monte Carlo Algorithms for Physically Based Rendering.PhD thesis.University of Leuven.1996.
[9]Eric P.Lafortune and Yves D.Willems.Bidirectional path tracing.In Compugraphics93'.1993.95-104.
[10]Appel,A.Some techniques for shading machine renderings of solids.AFIPS 1968 Spring Joint Computer Conf.1968.32:37-45.
[11]Arvo,J.Transfer equations in global illumination.Global illumination,SIGGRAPH 93Course Notes.1993.42:23-9.
[12]Fujimoto A,Tanaka T,Iwata K.ARTS:Accelerated ray t racing system.IEEE Computer Graphics and Applications.1986.6(4):16-26.
[13]Rubin S,Whitted T.A three dimensional representation for fast rendering of complex scenes.Computer Graphics.1980.14(3):110-116.
[14]Glassner A S.Space subdivision for fast ray t racing.IEEE Computer Graphics and Applications.1984.4(10):15-22.
[15]Reshetov A,Soupikov A,Hurley J.Multi-level ray tracing algorithm.ACM Transactions on Graphics,2005,24(3):1176-1185.
[16]Wald I,Slusallek P,Bent hin C,Wagner M.Interactive rendering wit h coherent ray tracing.Proceedings of the EUROGRAPHICS 2001.Los Angeles,California.2001.20(3):153-164.
[17]Wald I,Lze T,Kensler A,Knoll A,Parker S G.Ray tracing animated scenes using coherent grid traversal.ACM Transactions on Graphics.2006.25(3):485-493.
[18]Carr N A,Hoberock J,Crane K,Hart J C.Fast GPU ray tracing of dynamic meshes using geometry images.Proceedings of the Graphics Interface 2006.Quebec,Canada.2006:203-209.
[19]陈为,彭群生,鲍虎军.视点相关的层次采样:一种硬件加速体光线投射算法.软件学报.2006.17(3).587-601.
[20]黄沛杰,王文成等.基于中介面加快光线跟踪计算.计算机学报.2007.30(2):262-271.
[21]苗兰芳,黄劲,郑文庭,鲍虎军,彭群生.点模型的局部几何重建和光线跟踪.计算机辅助设计与图形学学报.2006.18(6).805-811.
[22] Cindy M. Goral, Kenneth E. Torrance,etc. Modeling the interaction of light between diffuse surfaces. Computer Graphics. 1984.18(3):212-222.
[23] Michael F. Cohen, Donald P. Greenberg. The Hemi-Cube: A radiosity solution for complex environments. Computer Graphics. 1985.19(3):31-40.
[24] David S. Immel, Michael F. Cohen, Donald P. Greenberg. A radiosity method for non-diffuse environments. Computer Graphics.l986.20(4):133-142.
[25] John R. Wallace, Michael F. Cohen, Donald P. Greenberg. A two-pass solution to the rendering equation: A synthesis of ray tracing and radiosity methods. Computer Graphics.l987.21(4):311-320.
[26] Brian Smits,James Arvo, David Salesin. An importance driven radiosity algorithm. Computer Graphics. 1992.26(2):273-282.
[27]Brian Smits,James Arvo, Donald Greenberg. A clustering algorithm for radiosity in complex environments. In proceedings of SIGGRAPH. 1994.435-442.
[28] Pat Hanrahan, David Salzman, Larry Aupperle. A rapid hierarchical radiosity algorithm. Computer Graphics. 1991.25(4): 197-206.
[29] Daniel Lischinski,Filippo Tampieri,Donald Greenberg. Discontinuity meshing for accurate radiosity. IEEE Computer Graphics and Applications.1992.12(6):25-39.
[30] C .M.Goral,K .E.Torrance,D ,P.Greenberg,B .Bataile. Modeling the Interaction of Light between Diffuse Surfaces.Computer Graphics. 1984.18(3).213-222.
[31] T. Nishita,E. Nakamae,Continuous Tone Representation of Three-Dimensional Objects Taking Account of Shadows and Inter-reflection.Computer Graphics.l985.19(3).23-30.
[32] F. Sillion,C .Puech,A General Two-pass Method Integrating Specular and Diffuse Reflection,Computer Graphics. 1989.23(3).335-344.
[33] J. T.Kajiya. The Rendering Equation. Computer Graphics. 1986.20(4). 143-150.
[34] S. N .Pattanaik and S.P.Muder.Computation of global illumination by Monte Carlo simulation of particle model of light.In proceedings of the Third Eurographics Workshop on Rendering. Bristol,U K. 1992.71-83.
[35] R.F.Tobler,M. Feda,W. Purgathofer,A.Wilkie. A Hierarchical Subdivision Algorithm for Stochastic Radiosity Methods.In Proceedings of the Eighth Eurographics Workshop on Rendering, France, 1997.193-203.
[36] P.Bekaert,L.N eumann,A.Neumann,M.Sbert,Y.D.Willems.Hierarchical MonteCarlo Radiosity.In Rendering Techniques'98(Proceedings of Eurographics Rendering Workshop'98),NewYork. 1998.259-268.
[37] J. Pope, A.Chalmers. Improving Hierarchical Monte Carlo Radiosity Algorithms.In The 8-th Intenrational Conference in Central Europe on Computer Graphics,Visualization and Interactive Digital Media.University of West Bohemia. 2000.244-251.
[38] F. Perez. Ignacio Martin and Xavier Pueyo:Hierarchical Monte Carlo Radiosity for General Environments.Technical Report II.Spain.2002.
[39] D.S.Immel,M.F.Cohen,D.P.Greenberg. A Radiosity Method for Non-diffuse Environments. Computer Graphics.l986.20(4).133-142.
[40] P. Hanrahan,D.Salzman,L.Upperle. A Rapid Hierarchical Radiosity Algorithm. Computer Graphics. 1991.25(4): 197-206.
[41] Henrik Wann Jensen. High Quality Rendering using Ray Tracing and Photon Mapping. Siggraph 2007.Course8.
[42]Henrik Wann Jensen.Global illumination using photon maps.Eurographics Rendering Workshop 1996,21-30.
[43]Henrik Wann Jensen,Per H.Christensen.Efficient simulation of light transport in scenes with participating media using photon maps.In Computer Graphics(ACM SIGGRAPH 98Proceedings).1998.311-320.
[44]Yanyun Chen,Xin Tong,Jiaping Wang.Shell Texture Functions.ACM Transactions on Graphics.2004.23(3):343-353.
[45]Oscar Anson,Veronica Sundstedt,Diego Gutierrez,Alan Chalmers.Efficient selective rendering of participating media.ACM International Conference Proceeding Series.2006.153:135-142.
[46]Timothy Purcell,Craig Donner,Mike Cammarano,Henrik Wann Jensen.Photon Mapping on Programmable Graphics Hardware.Proceedings of the ACM SIGGRAPH/EUROGRAPHICS conference on Graphics hardware.2003.41-50.
[47]Per H.Christensen.Faster photon map global illumination.Journal of Graphics Tools.2000.4(3):1-10.
[48]Vincent C.H.Ma,Michael D.McCool.Low latency photon mapping using block hashing.Proceedings of the ACM SIGGRAPH conference on Graphics hardware.2002.89-99.
[49]邹湘军,孙健等.虚拟现实技术的演变发展与展望.系统仿真学报.2004.16(9):1905-1909.
[50]Henry Baumgartener.Link Flight Trainer is designated a historic mechanical engineering landmark,http://www.asmenews.org/archives/backissues/aug00/features/link.html.2008.1.
[51]鲍虎军.虚拟现实技术概论.中国基础科学.2003.3:26-32.
[52]Warren Robinett.Virtual Environment Workstation.http://www.warrenrobinett.com.2008,1.
[53]Fisher,Scott S.,James Humphries,Michael McGreevy,Warren Robinett.The Virtual Environment Display System.ACM Workshop on Interactive 3D Graphics,1986.
[54]J.D.Foley.Interfaces for Advanced Computing.Scientific American,1987,257(4):127-135.
[55]Burdea,G.and P.Coiffet.Virtual Reality Technology.New York,USA:John Wiley & Sons,1994.
[56]黄雷,李军义,张鑫,彭群生.双层介质光线散射效果的实时绘制.计算机辅助殴计与图形学学报.2007.19(11):1423-1428.
[57]王长波,王章野,周麒,彭群生.海市蜃楼现象的真实感绘制.计算机学报.2006.29(12):2080-2085.
[58]方建文,于金辉,姚(王争),彭韧.利用GPU对3D角色模型绘制水墨效果.计算机辅助设计与图形学学报.2007.19(4):415-418.
[59]宋成芳,谈奇峰,张龙,龚怿,陈为,彭群生.风场作用下的动态森林场景的实时仿真.计算机辅助设计与图形学学报.2007.19(3):323-328.
[60]陈越强,冯玉瑜,邓建松.有理B样条曲面的区间隐式化.计算机辅助设计与图形学学报.2007.19(7):849-853,860.
[61]曹卫群,鲍虎军.基于隐函数插值的连续多分辩率模型.软件学报.2000.11(9):1248-1256.
[62]Yokokohji Y,Hollis R L,Kanade T.What you can see is what you can feel.Proc.of the IEEE Annual International Symposium on Virtual Reality.1996.46-53.
[63]Khatib O,Brock O,Chang K,et al.Robotics & interactive simulation.Communication of the ACM.2002.45(3):46-51.
[64]Machado L S,Mello A N,Lopes R D,et al.A virtual reality simulator for bone marrow harvest for pediatric transplant.Studies in Health Technology and Informatics.2001.81:293-297.
[65]Popescu V G,Burdea G C,BouzitM,et al.A virtual reality based telerehabilitation system with force feedback.IEEE Trans on Information Technology in Biomedicine.2000.4(1):45-51.
[66]Kthnapfel U,Kuhn C,HübnerM,et al.Endoscopic surgery trainer as an example for virtual reality in medical education,http://iregt1.iai.fzk.de/KISMET/docs/UKMITAT.html,2008.
[67]Williams R,Srivastava M,Conatser J.Implementation and evaluation of a haptic playback system,http://www.hapticse.org.2008.
[68]Jayaram S,Wang Y,Jayaram U,et al.A virtual assembly design environment.Proc.of IEEE Conference on Virtual Reality.1999:172-179.
[69]王修晖,华炜,鲍虎军.面向多投影显示墙的手势交互系统设计与实现.计算机辅助设计与图形学学报.2007.19(3):318-322,328.
[70]H.Noser,C.Stem,P.Stucki.Distributed Virtual Reality environments based on rewriting systems.IEEE transactions on Visualization and Computer Graphics.2003.9(2):213-225.
[71]赵沁平,沈旭昆等.DVENET:一个分布式虚拟环境.计算机研究与发展.1998.35(12):1064-1068.
[72]何红梅,于兆其,陈小武.DVENET应用程序框架的设计与实现.计算机研究与发展,1998,35(12):1069-1072.
[73]赵沁平,沈旭昆,吴威等.分布式虚拟环境DVENET研究进展.系统仿真学报,2000,12(7):291-295.
[74]廖祝华,刘晓平.EAST装配仿真的三维交互和用户界面设计.系统仿真学报.2004,16(10):2329-2331.
[75]杨克俭,刘舒燕等.虚拟现实与城市规划.系统仿真学报,2000,12(3):207-209.
[76]陈皓,刘晓平.基于模板的虚拟现实平台,系统仿真学报,2006.18(12):3434-3437.
[77]吕耀怀.虚拟技术在道德教育中的运用.系统仿真学报,2002.14(1):110-111.
[78]刘列明,吴恩华.一种基于点光源的三维阴影的实时生成算法.软件学报.2000.11(6):785-790.
[79]吴恩华,柳有权.基于图形处理器(GPU)的通用计算.计算机辅助设计与图形学学报.2004,16(5):601-612.
[80]Williams,L.Casting curved shadows on curved surfaces.In Proc.SIGGRAPH,1978.12:270-274.
[81]Fernando R,Fernandez S,Bala K,et al.Adaptive Shadow Maps.Proceedings of Siggraph 2001.Los Angeles:Acm Siggraph.2001:387-390.
[82]Hasenfratz J M,Lapierre M,Holzschuchn,et al.A Survey of Real-Time Soft Shadow's Algorithms.Computer Graphics Forum.2003,22(4):753-774.
[83]LAINE S,AILA T,ASSARSSON U,et al.Soft shadow volumes for ray tracing.ACM Trans Graph.2005,24(3):1156-1165.
[84]周国民,卢涤非,张其前.一种梯形结构的软阴影锥生成方法.浙江大学学报.2007.34(6):628-632.
[85]王长波,谢步瀛,彭群生.建筑物阴影的实时模拟.武汉大学学报:工学版.2006.39(4):120-126,146.
[86]Reeves,W.,Salesin,D.,Cook,R.Rendering antialiased shadows with depth maps.In Proc.SIGGRAPH.1987.21(4):283-291.
[87]Williams D.,Andrew L.Variance Shadow Maps.Proceedings of the 2006 Symposium On Interactive 3D Graphics and Games.2006.
[88]Kirsch F,Doellner J.Real-Time soft shadows using a single light sample.Journal of Winter School on Computer Graphics.2003.11(1):255-262.
[89]Peter-Pike Sloan,Jan Kautz,John Snyder.Precomputed Radiance Transfer for Real-Time Rendering in Dynamic,Low-Frequency Lighting Environments.ACM Transactions on Graphics 2002.21(3):527-536.
[90]王京,王莉莉,李帅.一种基于GPU的预计算辐射度传递全频阴影算法.计算机研究与发展,2006.,43(9):1505-1510.
[91]Anders Wang Kristensen,Tomas Akenine-Moller,Hem'ik Wann Jensen.Precomputed Local Radiance Transfer for Real-Time Lighting Design.ACM SIGGRAPH.2005.1208-1215.
[92]Tomas M611er,Ben Trumbore.Fast,minimum storage ray-triangle intersection.Journal of Graphics Tools.1997.2(1):21-28.
[93]S Molnar.A sorting classification of parallel rendering.IEEE Computer Graphics And Applications.1994.14(4):23-32.
[94]R Samanta et al.Load balancing for multi-projector rendering systems.Proceedings of the SIGGRAPH/Eurographics Workshop on Graphics Hardware,Los Angeles,CA,Auguest 1999:107-116.
[95]G Humphreys,M Eldridge et al.WireGL:a scalable graphics system for clusters.Computer Graphics Proceedings,Annual Conference Series,ACM SIGGRAPH,Los Angeles,Califomia 2001:129-140.
[96]Jian Yang,Jiaoying Shi,Zhefan Jin,Hui Zhang.Design and implementation of a large-scale hybrid distributed graphics system.Eurographics Workshop on Parallel Graphics and Visualization.Saarbruecken,Germany.2002:39-49.
[97]金哲凡,杨建,石教英.分布式并行绘制系统中几何指令流压缩的研究与实现.计算机辅助设计与图形学学报.2002.14(9):824-828.
[98]石教英,林海,金哲凡.数据分布型sort-first并行图形绘制系统的研究与实现.计算机研究与发展.2004.41(2):376-382.
[99]王炜,徐玮,崔忠辉.宽广视野虚拟环境漫游的设计与实现.计算机工程与设计.2007.28(9):2107-2110.
[100]季华,陈福民.带负载平衡策略的PC sort-first并行渲染系统.计算机仿真.2005.22(11):209-214.
[101]孙亚萍,陈福民.分布式渲染中动态任务划分算法的研究.微计算机应用.2007.28(1):43-46.
[102]季华,王永强,陈福民.基于PC集群的sort-first并行渲染系统负载平衡研究.微计算机应用.2007.28(8):859-862.
[103]William Gropp,Ewing Lusk,Anthony Skjellum.Using MPI:portable parallel programming with the message-passing interface Cambridge,Mass.MIT Press,1999.
[104]Erik Reinhard,Alan Chalmers,Frederik W.Jansen.Hybrid Scheduling for Parallel Rendering using Coherent Ray Tasks.Proceedings of the 1999 IEEE symposium on Parallel visualization and graphics.1999.21-28.
[105]李亚峰,秦开怀.基于光学映射虚物体的并行绘制.中国图象图形学报,2003.8(12):1432-1437.
[106]刘晓平,余烨等.一种协同渲染环境下的场景管理策略,系统仿真学报.2007.19(1):85-88.
[107]翟磊,贝佳等.一种可扩展的远程渲染体系结构研究.系统仿真学报.2006.18(4):1081-1083.
[108]Wen-yuan Liu,Chun-jing Xiao,et al.Study on combining subtractive clustering with fuzzy c-means clustering.Proceedings of the Second International Conference on Machine Learning and Cybernetics.2003.2659-2662.
[109]陈燕.对两个经典聚类算法的分析.现代电子技术.2007.17(256):174-176.