交互式虚拟人运动生成与控制算法研究
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摘要
随着体育训练、军事作战、工程测试、计算机游戏以及影视娱乐等行业对人体动画需求的日益增加,人们不仅要求虚拟人的运动高度真实,而且希望虚拟人能灵活地与外界交互并具有智能。本文以生成交互式的真实感虚拟人运动为主要研究内容,分别对虚拟人运动的混合驱动方式、平衡和保护动作生成、用户控制的虚拟人运动、目标导向的运动合成等方面进行了较为深入的研究,提出了相应的算法和实现方法,具体研究内容包括：
提出一种结合运动捕获数据驱动和动力学模拟的混合控制算法。本算法采用了两个并行计算进程,通过恢复运动数据集对神经网络进行训练,并根据虚拟人的恢复动作策略,借助该神经网络对运动数据库做预分类,有效地降低了后续的搜索范围。实验结果表明,本算法可以驱动虚拟人在两种运动控制方式之间实现灵活的切换。
提出一种虚拟人运动中受扰的平衡保持和保护动作生成算法。本算法能快速检测虚拟人在运动中的平衡状态,并在虚拟人有摔倒倾向时驱动虚拟人采取自主的保护动作以减少倒地对身体造成的伤害。实验结果表明,本算法设计的平衡保持和保护动作控制器适合应用在交互式游戏及其他实时人体动画生成中。
提出一种基于运动片断的交互式虚拟人运动生成算法。本算法采用支持向量机预测用户未来的输入信号,并生成控制策略表,能快速选择最优的下一个运动片段并生成最终的交互式人体动画。实验结果表明,本算法可以获得较高真实感的交互式人体动画,并且控制策略生成的时间-空间开销均较低。
提出一种目标导向的虚拟人运动片段优化搜索和控制算法。本算法由用户提供少量关于最终生成运动的信息,系统能根据场景特征自动设定障碍物约束,并基于一个合适规模的运动片断数据库,用优化方法不断地搜索出运动片断,最终生成尽可能满足用户要求且视觉上自然的人体动画。实验结果表明,本算法在虚拟体操运动的应用中能较好地生成满足用户指定要求的人体动画。
With the increasing requirements of character animation in sport training, military training, engineering testing, computer games and movies, the generated character motions are not only required to be highly realistic, but the characters are also expected to intelligently interact with the environment. Generating realistic and interactive virtual character motion is the main research content of this dissertation, which focuses on the hybrid driven approach of the character motion, the balance keeping and protective actions, the user-controlled virtual character and the goal-oriented character motion synthesis. In this dissertation, we put forward the corresponding algorithms and their implementations, which including:
We present a hybrid control algorithm which combines the motion capture data and the dynamic simulation techniques together. We employ a parallel algorithm of two processes, as well as training an artificial neural network by a set of recovery motion capture data sequences, and predicting and pre-classifying the recovery motion database according to the recovery motion strategy of the characters, so reducing the size of the search region. The experimental results indicate that our characters can be controlled and switched between motion capture and dynamic simulation control modes naturally.
We present a character balance keeping and protective motion generation algorithm in locomotion. The algorithm can detect the balance of the character in locomotion and drives him to take several active and protective responses when he falls to the ground. The experimental results indicate that our balance keeping and protective motion controller is suitable for interactive games or other real-time applications.
We present a motion fragment based interactive character motion generation algorithm. We employ a SVM to add the prediction of the user's future inputs in the control process, then selecting a motion fragment, and finally creating a motion stream from several short motion fragments to generate interactive motion. The experimental results indicate that our control method achieves higher visual quality and lower space-time costs in the control policy synthesis than the previous methods.
We present a goal-oriented character motion fragment optimization search and control algorithm. The user provides information of the final character motion, and the system sets the obstacles of the scene automatically. Based on a motion capture database with appropriate size, our algorithm is able to continually search out the motion fragments, so that the final motion has high visual effect, as well as meeting the user's requirements as much as possible. The experimental results indicate that the algorithm is suitable for user-specified gymnastics animation synthesis.
提出一种结合运动捕获数据驱动和动力学模拟的混合控制算法。本算法采用了两个并行计算进程,通过恢复运动数据集对神经网络进行训练,并根据虚拟人的恢复动作策略,借助该神经网络对运动数据库做预分类,有效地降低了后续的搜索范围。实验结果表明,本算法可以驱动虚拟人在两种运动控制方式之间实现灵活的切换。
提出一种虚拟人运动中受扰的平衡保持和保护动作生成算法。本算法能快速检测虚拟人在运动中的平衡状态,并在虚拟人有摔倒倾向时驱动虚拟人采取自主的保护动作以减少倒地对身体造成的伤害。实验结果表明,本算法设计的平衡保持和保护动作控制器适合应用在交互式游戏及其他实时人体动画生成中。
提出一种基于运动片断的交互式虚拟人运动生成算法。本算法采用支持向量机预测用户未来的输入信号,并生成控制策略表,能快速选择最优的下一个运动片段并生成最终的交互式人体动画。实验结果表明,本算法可以获得较高真实感的交互式人体动画,并且控制策略生成的时间-空间开销均较低。
提出一种目标导向的虚拟人运动片段优化搜索和控制算法。本算法由用户提供少量关于最终生成运动的信息,系统能根据场景特征自动设定障碍物约束,并基于一个合适规模的运动片断数据库,用优化方法不断地搜索出运动片断,最终生成尽可能满足用户要求且视觉上自然的人体动画。实验结果表明,本算法在虚拟体操运动的应用中能较好地生成满足用户指定要求的人体动画。
With the increasing requirements of character animation in sport training, military training, engineering testing, computer games and movies, the generated character motions are not only required to be highly realistic, but the characters are also expected to intelligently interact with the environment. Generating realistic and interactive virtual character motion is the main research content of this dissertation, which focuses on the hybrid driven approach of the character motion, the balance keeping and protective actions, the user-controlled virtual character and the goal-oriented character motion synthesis. In this dissertation, we put forward the corresponding algorithms and their implementations, which including:
We present a hybrid control algorithm which combines the motion capture data and the dynamic simulation techniques together. We employ a parallel algorithm of two processes, as well as training an artificial neural network by a set of recovery motion capture data sequences, and predicting and pre-classifying the recovery motion database according to the recovery motion strategy of the characters, so reducing the size of the search region. The experimental results indicate that our characters can be controlled and switched between motion capture and dynamic simulation control modes naturally.
We present a character balance keeping and protective motion generation algorithm in locomotion. The algorithm can detect the balance of the character in locomotion and drives him to take several active and protective responses when he falls to the ground. The experimental results indicate that our balance keeping and protective motion controller is suitable for interactive games or other real-time applications.
We present a motion fragment based interactive character motion generation algorithm. We employ a SVM to add the prediction of the user's future inputs in the control process, then selecting a motion fragment, and finally creating a motion stream from several short motion fragments to generate interactive motion. The experimental results indicate that our control method achieves higher visual quality and lower space-time costs in the control policy synthesis than the previous methods.
We present a goal-oriented character motion fragment optimization search and control algorithm. The user provides information of the final character motion, and the system sets the obstacles of the scene automatically. Based on a motion capture database with appropriate size, our algorithm is able to continually search out the motion fragments, so that the final motion has high visual effect, as well as meeting the user's requirements as much as possible. The experimental results indicate that the algorithm is suitable for user-specified gymnastics animation synthesis.
引文
[1]夏时洪,王兆其.虚拟人合成研究进展.中国科学F辑：信息科学,2009,39(5)：483-498
[2]A. Witkin, M. Kass. Space-time constraints. In:Proceedings of the 15th Annual Conference on Computer Graphics and Interactive Techniques (SIGGRAPH'88), ACM, New York, NY,1988:159-168
[3]M. F. Cohen. Interactive space-time control for animation. ACM SIGGRAPH Computer Graphics,1992,26(2):293-302
[4]M. Gleicher. Motion editing with space-time constraints. In:Proceedings of the 1997 Symposium on Interactive 3D Graphics (SI3D'97), Providence, Rhode Island, ACM, New York, NY,1997:139-148
[5]M. Gleicher. Comparing constraint-based motion editing methods. Graphical Models,2001,63(2):107-134
[6]许威威,潘志庚,葛云芳.基于足迹采样的运动编辑.计算机辅助设计与图形学学报,2003,15(7)：805-811
[7]A. Safonova, J. K. Hodgins, N. S. Pollard. Synthesizing physically realistic human motion in low-dimensional behavior-specific spaces. ACM Transactions on Graphics,2004,23(3):514-521
[8]A. Bruderlin, L. Williams. Motion signal processing. In:Proceedings of the 22nd Annual Conference on Computer Graphics and Interactive Techniques (SIGGRAPH'95), ACM, New York, NY,1995:97-104
[9]M. Unuma, K. Anjyo, R. Takeuchi. Fourier principles for emotion-based human figure. In:Proceedings of the 22nd Annual Conference on Computer Graphics and Interactive Techniques (SIGGRAPH'95), ACM, New York, NY,1995:91-96
[10]A. Witkin, Z. Popovi'c. Motion warping. In:Proceedings of the 22nd Annual Conference on Computer Graphics and Interactive Techniques (SIGGRAPH'95), ACM, New York, NY,1995:105-108
[11]K. Amaya, A. Bruderlin, T. Calvert. Emotion from motion. In:Proceedings of the Conference on Graphics Interface, Toronto, Canada, Canadian Information Processing Society, Toronto, Canada,1996:222-229
[12]G. D. Liu, Z. G. Pan, Z. Y. Lin. Style subspaces for character animation. Computer Animation and Virtual Worlds,2008,19(3-4):199-209
[13]H. J. Shin, L. Kovar, M. Gleicher. Physical touch-up of human motions. In: Proceedings of the 11th Pacific Conference on Computer Graphics and Applications (PG2003), IEEE Computer Society, Washington, DC,2003:194-203
[14]V. B. Zordan, N. V. D. Horst. Mapping optical motion capture data to skeletal motion using a physical model. In:Proceedings of ACM SIGGRAPH Eurographics Symposium on Computer Animation, San Diego, California, Symposium on Computer Animation,2003:245-250
[15]M. Neff, E. Fiume. Aesthetic edits for character animation. In:Proceedings of ACM SIGGRAPH/Eurographics Symposium on Computer Animation, San Diego, California,2003:239-244
[16]Y. Ye, C. K. Liu. Animating responsive characters with dynamic constraints in near-unactuated coordinates. ACM Transactions on Graphics,2008,27(5):1-5
[17]魏毅,夏时洪,王兆其.基于物理的人体空中运动仿真.软件学报,2008,19(12)：3228-3236
[18]J. Lasseter. Principles of traditional animation applied to 3D computer animation. In:Proceedings of the 14th Annual Conference on Computer Graphics and Interactive Techniques (SIGGRAPH'87), ACM, New York, NY,1987:35-44
[19]庄越挺,肖俊,吴飞,杨涛.发明专利：三维人体运动数据关键帧提取方法.专利号：ZL200610053399.5,浙江大学,2006
[20]庄越挺,肖俊,吴飞,吴伊自.发明专利：基于运动脚本的三维人体动画自动生成方法.专利号：ZL200610053396.1,浙江大学,2006
[21]F. Multon, L. France, M. P. C. Gascuel, et al. Computer animation of human walking:a survey. The Journal of Visualization and Computer Animation,1999, 10(1):39-54
[22]R. Boulic, D. Thalmann, N. M. Thalmann. A global human walking model with real time kinematic personification. The Visual Computer,1990,6(6):344-358
[23]K. Perlin. Real time responsive animation with personality. IEEE Transactions on Visualization and Computer Graphics,1995,1(1):5-15
[24]K. Perlin, A. Goldberg. Improv:A system for scripting interactive actors in virtual worlds. In:Proceedings of the 23rd Annual Conference on Computer Graphics and Interactive Techniques (SIGGRAPH'96), ACM, New York, NY,1996:205-216
[25]宋顺林,詹永照,薛安容.三维计算机动画中人体建模方法的研究.软件学报,1995,6(5)：311-315
[26]宋顺林,詹永照,薛安容.三维人体行走模型的研究与实现.计算机学报,1996,19(6)：429-434
[27]H. Sun, D. Metaxas. Automating gait generation. In:Proceedings of the 28th Annual Conference on Computer Graphics and Interactive Techniques, (SIGGRAPH'01), ACM, New York, NY,2001:261-270
[28]R. Boulic, B. Ulicny, D. Thalmann. Versatile walk engine. Journal of Game Development,2004,1(1):25-52
[29]石敏,朱登明,王兆其等.三维地形中人体运动生成方法.系统仿真学报,2006,18(5)：1247-1253
[30]李淳芃,王兆其,夏时洪.人体运动的函数数据分析与合成.软件学报,2009,’20(6)：1664-1672
[31]J. Hodgins, W. Wooten, D. Brogan, et al. Animating human athletics. In: Proceedings of the 22nd Annual Conference on Computer Graphics and Interactive Techniques (SIGGRAPH'95), ACM, New York, NY,1995:71-78
[32]W. Wooten, J. Hodgins. Animation of human diving. Computer Graphics Forum, 1996,15(1):3-13
[33]J. Laszlo, M. V. D. Panne, E. Fiume. Limit cycle control and its application to the animation of balancing and walking. In:Proceedings of the 23rd Annual Conference on Computer Graphics and Interactive Techniques (SIGGRAPH'96), ACM, New York, NY,1996:155-162
[34]H. Ko, N. Badler. Animating human locomotion with inverse dynamics. IEEE Computer Graphics and Applications,1996,16(2):50-58
[35]J. Hodgins, N. Pollard. Adapting simulated behaviors for new characters. In: Proceedings of the 24th Annual Conference on Computer Graphics and Interactive Techniques, ACM Press/Addison-Wesley Publishing Co., New York, NY,1997: 153-162
[36]P. Faloutsos, M. V. D. Panne, D. Terzopoulos. Composable controllers for physics-based character animation. Proceedings of the 28th Annual Conference on Computer Graphics and Interactive Techniques (SIGGRAPH'01), ACM, New York, NY,2001:251-260
[37]M. Neff, E. Fiume. Modeling tension and relaxation for computer animation. Proceedings of ACM SIGGRAPH/Eurographics Symposium on Computer Animation (SCA'02), San Antonio, Texas, ACM, New York, NY,2002:81-88
[38]M. Neff, E. Fiume. AER:Aesthetic exploration and refinement for expressive character animation. In:Proceedings of the 2005 ACM SIGGRAPH/Eurographics Symposium on Computer Animation (SCA'05), Los Angeles, California, ACM, New York, NY,2005:161-170
[39]D. A. Winter. Biomechanics and motor control of human movement, Wiley,2004
[40]D. Silva, M. Durand, J. Popovic. Linear bellman combination for control of character animation. ACM Transactions on Graphics,2009,28(3):1-10
[41]Z. G Pan, X. Cheng, W. Z. Chen, et al. Real time falling animation with active and protective responses. The Visual Computer,2009,25(5-7):487-497
[42]J. Starck, G. Miller, A. Hilton. Video-based character animation. In:Proceedings of the 2005 ACM SIGGRAPH/Eurographics Symposium on Computer Animation (SCA'05), Los Angeles, California, ACM, New York, NY,2005:49-58
[43]黄河,邱显杰,王兆其.基于运动捕获的三维角色动画生成系统.第五届智能CAD与数字娱乐学术会议(CIDE2008),中国,大连,2008：100-107
[44]A. Shapiro, F. Pighin. Hybrid control for interactive character animation. In:The 11th Pacific Conference on Computer Graphics and Applications (PG2003), IEEE Computer Society, Washington DC,2003:455-461
[45]V. B. Zordan, J. Hodgins. Tracking and modifying upper-body human motion data with dynamic simulation. In:Proceedings of Eurographics Workshop on Computer Animation and Simulation (Eurographics'99),1999:13-22
[46]V. B. Zordan, J. Hodgins. Motion capture-driven simulations that hit and react. In: Proceedings of the 2002 ACM SIGGRAPH/Eurographics Symposium on Computer Animation (SCA'02), San Antonio, Texas, ACM, New York, NY,2002: 89-96
[47]V. B. Zordan, A. Majkowska, B. Chiu, et al. Dynamic response for motion capture animation. ACM Transactions on Graphics,2005,24(3):697-701
[48]王裕国,潘峰,胡静倩.多种动态模拟和复杂三维动画控制的框架结构.软件学报,1997,8(8)：615-621
[49]B. Tang, Z. G. Pan, L. Zheng, et al. Interactive generation of falling motions. Computer Animation and Virtual World,2006,17(3-4):271-279
[50]A. Safonova, J. K. Hodgins. Construction and optimal search of interpolated motion graphs. ACM Transactions on Graphics,2007,26(3), Article 106,11 pages, DOI:10.1145/1239451.1239557
[51]J. McCann, N. Pollard. Responsive characters from motion fragments. ACM Transactions on Graphics, (SIGGRAPH 2007),2007,26(3), Article 6,7 pages, DOI:10.1145/1239451.1239457
[52]A. Treuille, Y. Lee, Z. Popovic. Near-optimal character animation with continuous control. ACM Transactions on Graphics,2007,26(3), Article 7,7 pages, DOI: 10.1145/1239451.1239458
[53]肖俊,庄越挺,吴飞.三维人体运动特征可视化与交互式运动分割.软件学报,2008,19(8)：1995-2003
[54]X. Cheng, G. D. Liu, Z. G. Pan, et al. Fragment based responsive character motion for interactive games. The Visual Computer,2009,25(5-7):479-485
[55]贺怀清,洪炳熔.一种虚拟人运动拟合算法.电子学报,2001,29(8)：1107-1109
[56]庄越挺,刘小明,潘云鹤.一种基于视频的人体动画骨架提取技术.计算机研究与发展,2000,37(4)：498-506
[57]L. Kovar, M. Gleicher, F. E. Pighin. Motion graphs. ACM Transactions on Graphics,2002,21 (3):473-482
[58]K. Yin, S. Coros, P. Beaudoin, et al. Continuation methods for adapting simulated skills. ACM Transactions on Graphics,2008,27(3):1-7
[59]王兆其.虚拟人合成研究综述.中国科学院研究生院学报,2000,17(2)：89-98
[60]罗忠祥,庄越挺,刘丰等.基于时空约束的运动编辑和运动重定向.计算机辅助设计与图形学学报,2002,14(12)：1146-1151
[61]T. Komura, H. Leung, J. Kuffner. Animating reactive motions for biped locomotion. In:The 2004 ACM Symposium on Virtual Reality Software and Technology (VRST'04), Hong Kong, ACM, New York, NY,2004:32-40
[62]O. Arikan, D. A. Forsyth, J. F. O'Brien. Pushing people around. In:The 2005 ACM SIGGRAPH/Eurographics Symposium on Computer Animation (SCA'05), Los Angeles, California, ACM, New York, NY,2005:59-66
[63]K. Yin, D.K. Pa, M.V. D. Panne. Data-driven interactive balancing behaviors. In: The 2005 Pacific Graphics, Macao, China,2005:118-120
[64]P. Faloutsos, M. V. D. Panne, D. Terzopoulos. The virtual stuntman:dynamic characters with a repertoire of autonomous motor skills. Computers & Graphics, 2001,25(6):933-953
[65]A. Moravanszky. NovodeX physics SDK. http://www.ageia.com,2007-2-27
[66]M. Mandel. Versatile and interactive virtual humans:hybrid use of data-driven and dynamics-based motion synthesis. Carnegie Mellon University,2004
[67]纪习尚,宫宁生,朱梧榴.基于最优分类面的神经网络模式分类方法.计算机工程,2006,32(22)：206-209
[68]唐冰.反应跟随性人体动画生成研究.浙江大学博士论文,2006
[69]L. H. Pang, Y. S. Tan, C. F. Wong, et al. ODECAL:A flexible open source rag doll simulation engine. Technologies for E-Learning and Digital Entertainment,2006, LNCS 3942:680-687
[70]M. B. Sabick, J. G. Hay, S. A. Banks. Active response decrease impact forces at the hip and shoulder in falls to the side. Journal of Biomechanics,1999,32(9): 993-998
[71]F. Fabio, N. R. Stephen. Reducing hip fracture risk during sideways falls: evidence in young adults of the protective effects of impact to the hands and stepping. Journal of Biomechanics,2007,40(9):2612-2618
[72]M. Vukobratovic, B. Borovac, D. Surdilovic. Zero-moment point proper interpretation and new application. IEEE/RAS International Conference on Humanoid Robots,2001:237-244
[73]刘莉,汪劲松,陈恳等.基于六维力/力矩传感器的拟人机器人实际ZMP检测.机器人,2001,23(5)：459-466
[74]M. Oshita, A. Makinouchi. A dynamic motion control technique for human-like articulated figures. Eurographics 2001,20(3):192-202
[75]Y. C. Pai, J. Patton. Center of mass velocity-position predictions for balance control. Journal of Biomechanics,1997,30(4):347-154
[76]E. T. Hsiao, S. N. Robinovitch. Biomechanical influences on balance recovery by stepping. Journal of Biomechanics,1999,32(4):1099-1106
[77]M. Wu, L. H. Ji, D. W. Jin, et al. Minimal step length necessary for recovery of forward balance loss with a single step. Journal of Biomechanics,2007,40(9): 1559-1566
[78]武明,季林红,金德闻等.人体站立受扰平衡策略的实验研究.清华大学学报(自然科学版),2003,43(2)：152-155
[79]N. R. Stephen, B. Rebecca, M. Jessica. Effect of the squat protective response on impact velocity during backward falls. Journal of Biomechanics,2004,37(9): 1329-1337
[80]A. L. Hof, M. G. J. Gazendam, W. E. Sinke. The condition for dynamic stability. Journal of Biomechanics,2005,38(9):1-8
[81]S. L. Delp, J. P. Loan, M. G. Hoy, et al. An interactive graphics-based model of the lower extremity to study orthopaedic surgical procedures. IEEE Transactions on Biomedical Engineering,1990,37(8):757-767
[82]R. C. Miall, D. J. Weir, D. M. Wolpert, et al. Is the cerebellum a smith predictor? Journal of Motor Behaviour,1993,25(3):203-216
[83]S. Arya, D. Mount. Approximate nearest neighbor queries in fixed dimensions. In: Proceedings of the Fourth Annual ACM-SIAM Symposium on Discrete Algorithms, Austin, Texas, United States, Society for Industrial and Applied Mathematics, Philadelphia, PA,1993:271-280
[84]J. Lee, S. Y. Shin. A hierarchical approach to interactive motion editing for humanlike figures. In:The 26th Annual Conference on Computer Graphics and Interactive Techniques, ACM Press/Addison-Wesley Publishing Co., New York, NY,1999:39-48
[85]N. Thalmann, D. Thalmann. Virtual humans:thirty years of research, what next? The Visual Computer,2005,21(12):997-1015
[86]刘莉,王兆其,朱登明等.基于运动轨迹重构的运动编辑.计算机辅助设计与图形学学报,2006,18(10)：1613-1618
[87]D. M. Zhu, Z. Q. Wang, S. H. Xia. Motion editing with the state feedback dynamic model. In:Computer Graphics International (CGI'06), Hangzhou, China, LNCS 4035,2006:348-359
[88]M. Gleicher, H. J. Shin, L. Kovar, et al. Snap-together motion:assembling run-time animations. ACM Transactions on Graphics,2003,22(3):181-188
[89]O. Arikan, D. A. Forsyth. Interactive motion generation from examples. ACM Transactions on Graphics,2002,21(3):483-490
[90]R. Heck, M. Gleicher. Parametric motion graphs. In:Proceedings of the 2007 Symposium on Interactive 3D Graphics and Games (I3D'07), Seattle, Washington, ACM, New York, NY,2007:129-136
[91]K. Pullen, C. Bregler. Motion capture assisted animation:texturing and synthesis. In:Proceedings of the 29th Annual Conference on Computer Graphics and Interactive Techniques (SIGGRAPH'02), San Antonio, Texas, ACM, New York, NY,2002:501-508.
[92]A. Schodl, I. Essa. A machine learning for video based rendering technical report. GIT-GVU-00-11, Georgia Institute of Technology,2000
[93]O. Arikan, D. A. Forsyth, J. F. O'brien. Motion synthesis from annotations. ACM Transactions on Graphics,2003,22(3):402-408
[94]J. Chai, J. K. Hodgins. Performance animation from low-dimensional control signals. ACM Transactions on Graphics,2005,24(3):686-696
[95]V. B. Zordan, A. Macchietto, J. Medina, et al. Interactive dynamic response for games. In:Proceedings of the 2007 ACM SIGGRAPH Symposium on Video Games (Sandbox'07), San Diego, California, ACM, New York, NY,2007:9-14
[96]J. Lee, J Chai, P. S. A. Reitsma, et al. Interactive control of avatars animated with human motion data. ACM Transactions on Graphics,2002,21(3):491-500
[97]T. Kwon, S. Y. Shin. Motion modeling for on-line locomotion synthesis. In:ACM SIGGRAPH/Eurographics Symposium on Computer Animation (SCA'05), Los Angeles, California, ACM, New York, NY,2005:29-38
[98]K. H. Lee, M. G. Choi, J. Lee. Motion patches:Building blocks for virtual environments annotated with motion data. ACM Transactions on Graphics,2006, 25(3):898-906
[99]M. G. Choi, J. Lee, S. Y. Shin. Planning biped locomotion using motion capture data and probabilistic roadmaps. ACM Transactions on Graphics,2003,22(2): 182-203
[100]A. C. Fang, N. S. Pollard. Efficient synthesis of physically valid human motion. ACM Transactions on Graphics,2003,22(3):417-426
[101]M. Sung, L. Kovar, M. Gleicher. Fast and accurate goal-directed motion synthesis for crowds. In:Proceedings of the 2005 ACM SIGGRAPH/Eurographics Symposium on Computer Animation (SCA'05), Los Angeles, California, ACM, New York, NY,2005:291-300
[102]J. Lee, K. H. Lee. Pre-computing avatar behavior from human motion data. Graphics Models,2006,68(2):158-174
[103]M. Lau, J. Kuffher. Pre-computed search trees:planning for interactive goal-driven animation. In:Proceedings of the 2006 ACM SIGGRAPH Eurographics Symposium on Computer Animation, Vienna, Austria, Eurographics Association, Aire-la-Ville, Switzerland,2006:299-308
[104]S. I. Park, H. J. Shin, S. Y. Shin. On-line locomotion generation based on motion blending. In:ACM SIGGRAPH/Eurographics Symposium on Computer Animation (SCA'02), San Antonio, Texas, ACM, New York, NY,2002:105-112
[105]S. I. Park, H. J. Shin, T. H. Kim, et al. Online motion blending for real-time locomotion generation. Computer Animation and Virtual Worlds,2004,15(3-4): 125-138
[106]H. J. Shin, H. S. Oh. Fat graphs:constructing an interactive character with continuous controls. In:ACM SIGGRAPH/Eurographics Symposium on Computer Animation, Vienna, Austria, Eurographics Association, Aire-la-Ville, Switzerland,2006:291-298
[107]L. P. Kaelbling, M. L. Littman, A. W. Moore. Reinforcement learning:a survey. Journal of Artifcial Intelligence Research,1996, Vol 4:237-285
[108]C. G. Atkeson, A. W. Moore, S. Schaal. Locally weighted learning for control. Artificial Intelligence Review,1997,11(1-5):75-113
[109]D. P. Bertsekas. Dynamic Programming and Optimal Control. Athena Scientific, 2001
[110]D. Farias. The linear programming approach to approximate dynamic programming:theory and application. PhD thesis, Stanford University,2002
[111]S. M. Lavalle. Planning algorithms. Cambridge University Press,2006
[2]A. Witkin, M. Kass. Space-time constraints. In:Proceedings of the 15th Annual Conference on Computer Graphics and Interactive Techniques (SIGGRAPH'88), ACM, New York, NY,1988:159-168
[3]M. F. Cohen. Interactive space-time control for animation. ACM SIGGRAPH Computer Graphics,1992,26(2):293-302
[4]M. Gleicher. Motion editing with space-time constraints. In:Proceedings of the 1997 Symposium on Interactive 3D Graphics (SI3D'97), Providence, Rhode Island, ACM, New York, NY,1997:139-148
[5]M. Gleicher. Comparing constraint-based motion editing methods. Graphical Models,2001,63(2):107-134
[6]许威威,潘志庚,葛云芳.基于足迹采样的运动编辑.计算机辅助设计与图形学学报,2003,15(7)：805-811
[7]A. Safonova, J. K. Hodgins, N. S. Pollard. Synthesizing physically realistic human motion in low-dimensional behavior-specific spaces. ACM Transactions on Graphics,2004,23(3):514-521
[8]A. Bruderlin, L. Williams. Motion signal processing. In:Proceedings of the 22nd Annual Conference on Computer Graphics and Interactive Techniques (SIGGRAPH'95), ACM, New York, NY,1995:97-104
[9]M. Unuma, K. Anjyo, R. Takeuchi. Fourier principles for emotion-based human figure. In:Proceedings of the 22nd Annual Conference on Computer Graphics and Interactive Techniques (SIGGRAPH'95), ACM, New York, NY,1995:91-96
[10]A. Witkin, Z. Popovi'c. Motion warping. In:Proceedings of the 22nd Annual Conference on Computer Graphics and Interactive Techniques (SIGGRAPH'95), ACM, New York, NY,1995:105-108
[11]K. Amaya, A. Bruderlin, T. Calvert. Emotion from motion. In:Proceedings of the Conference on Graphics Interface, Toronto, Canada, Canadian Information Processing Society, Toronto, Canada,1996:222-229
[12]G. D. Liu, Z. G. Pan, Z. Y. Lin. Style subspaces for character animation. Computer Animation and Virtual Worlds,2008,19(3-4):199-209
[13]H. J. Shin, L. Kovar, M. Gleicher. Physical touch-up of human motions. In: Proceedings of the 11th Pacific Conference on Computer Graphics and Applications (PG2003), IEEE Computer Society, Washington, DC,2003:194-203
[14]V. B. Zordan, N. V. D. Horst. Mapping optical motion capture data to skeletal motion using a physical model. In:Proceedings of ACM SIGGRAPH Eurographics Symposium on Computer Animation, San Diego, California, Symposium on Computer Animation,2003:245-250
[15]M. Neff, E. Fiume. Aesthetic edits for character animation. In:Proceedings of ACM SIGGRAPH/Eurographics Symposium on Computer Animation, San Diego, California,2003:239-244
[16]Y. Ye, C. K. Liu. Animating responsive characters with dynamic constraints in near-unactuated coordinates. ACM Transactions on Graphics,2008,27(5):1-5
[17]魏毅,夏时洪,王兆其.基于物理的人体空中运动仿真.软件学报,2008,19(12)：3228-3236
[18]J. Lasseter. Principles of traditional animation applied to 3D computer animation. In:Proceedings of the 14th Annual Conference on Computer Graphics and Interactive Techniques (SIGGRAPH'87), ACM, New York, NY,1987:35-44
[19]庄越挺,肖俊,吴飞,杨涛.发明专利：三维人体运动数据关键帧提取方法.专利号：ZL200610053399.5,浙江大学,2006
[20]庄越挺,肖俊,吴飞,吴伊自.发明专利：基于运动脚本的三维人体动画自动生成方法.专利号：ZL200610053396.1,浙江大学,2006
[21]F. Multon, L. France, M. P. C. Gascuel, et al. Computer animation of human walking:a survey. The Journal of Visualization and Computer Animation,1999, 10(1):39-54
[22]R. Boulic, D. Thalmann, N. M. Thalmann. A global human walking model with real time kinematic personification. The Visual Computer,1990,6(6):344-358
[23]K. Perlin. Real time responsive animation with personality. IEEE Transactions on Visualization and Computer Graphics,1995,1(1):5-15
[24]K. Perlin, A. Goldberg. Improv:A system for scripting interactive actors in virtual worlds. In:Proceedings of the 23rd Annual Conference on Computer Graphics and Interactive Techniques (SIGGRAPH'96), ACM, New York, NY,1996:205-216
[25]宋顺林,詹永照,薛安容.三维计算机动画中人体建模方法的研究.软件学报,1995,6(5)：311-315
[26]宋顺林,詹永照,薛安容.三维人体行走模型的研究与实现.计算机学报,1996,19(6)：429-434
[27]H. Sun, D. Metaxas. Automating gait generation. In:Proceedings of the 28th Annual Conference on Computer Graphics and Interactive Techniques, (SIGGRAPH'01), ACM, New York, NY,2001:261-270
[28]R. Boulic, B. Ulicny, D. Thalmann. Versatile walk engine. Journal of Game Development,2004,1(1):25-52
[29]石敏,朱登明,王兆其等.三维地形中人体运动生成方法.系统仿真学报,2006,18(5)：1247-1253
[30]李淳芃,王兆其,夏时洪.人体运动的函数数据分析与合成.软件学报,2009,’20(6)：1664-1672
[31]J. Hodgins, W. Wooten, D. Brogan, et al. Animating human athletics. In: Proceedings of the 22nd Annual Conference on Computer Graphics and Interactive Techniques (SIGGRAPH'95), ACM, New York, NY,1995:71-78
[32]W. Wooten, J. Hodgins. Animation of human diving. Computer Graphics Forum, 1996,15(1):3-13
[33]J. Laszlo, M. V. D. Panne, E. Fiume. Limit cycle control and its application to the animation of balancing and walking. In:Proceedings of the 23rd Annual Conference on Computer Graphics and Interactive Techniques (SIGGRAPH'96), ACM, New York, NY,1996:155-162
[34]H. Ko, N. Badler. Animating human locomotion with inverse dynamics. IEEE Computer Graphics and Applications,1996,16(2):50-58
[35]J. Hodgins, N. Pollard. Adapting simulated behaviors for new characters. In: Proceedings of the 24th Annual Conference on Computer Graphics and Interactive Techniques, ACM Press/Addison-Wesley Publishing Co., New York, NY,1997: 153-162
[36]P. Faloutsos, M. V. D. Panne, D. Terzopoulos. Composable controllers for physics-based character animation. Proceedings of the 28th Annual Conference on Computer Graphics and Interactive Techniques (SIGGRAPH'01), ACM, New York, NY,2001:251-260
[37]M. Neff, E. Fiume. Modeling tension and relaxation for computer animation. Proceedings of ACM SIGGRAPH/Eurographics Symposium on Computer Animation (SCA'02), San Antonio, Texas, ACM, New York, NY,2002:81-88
[38]M. Neff, E. Fiume. AER:Aesthetic exploration and refinement for expressive character animation. In:Proceedings of the 2005 ACM SIGGRAPH/Eurographics Symposium on Computer Animation (SCA'05), Los Angeles, California, ACM, New York, NY,2005:161-170
[39]D. A. Winter. Biomechanics and motor control of human movement, Wiley,2004
[40]D. Silva, M. Durand, J. Popovic. Linear bellman combination for control of character animation. ACM Transactions on Graphics,2009,28(3):1-10
[41]Z. G Pan, X. Cheng, W. Z. Chen, et al. Real time falling animation with active and protective responses. The Visual Computer,2009,25(5-7):487-497
[42]J. Starck, G. Miller, A. Hilton. Video-based character animation. In:Proceedings of the 2005 ACM SIGGRAPH/Eurographics Symposium on Computer Animation (SCA'05), Los Angeles, California, ACM, New York, NY,2005:49-58
[43]黄河,邱显杰,王兆其.基于运动捕获的三维角色动画生成系统.第五届智能CAD与数字娱乐学术会议(CIDE2008),中国,大连,2008：100-107
[44]A. Shapiro, F. Pighin. Hybrid control for interactive character animation. In:The 11th Pacific Conference on Computer Graphics and Applications (PG2003), IEEE Computer Society, Washington DC,2003:455-461
[45]V. B. Zordan, J. Hodgins. Tracking and modifying upper-body human motion data with dynamic simulation. In:Proceedings of Eurographics Workshop on Computer Animation and Simulation (Eurographics'99),1999:13-22
[46]V. B. Zordan, J. Hodgins. Motion capture-driven simulations that hit and react. In: Proceedings of the 2002 ACM SIGGRAPH/Eurographics Symposium on Computer Animation (SCA'02), San Antonio, Texas, ACM, New York, NY,2002: 89-96
[47]V. B. Zordan, A. Majkowska, B. Chiu, et al. Dynamic response for motion capture animation. ACM Transactions on Graphics,2005,24(3):697-701
[48]王裕国,潘峰,胡静倩.多种动态模拟和复杂三维动画控制的框架结构.软件学报,1997,8(8)：615-621
[49]B. Tang, Z. G. Pan, L. Zheng, et al. Interactive generation of falling motions. Computer Animation and Virtual World,2006,17(3-4):271-279
[50]A. Safonova, J. K. Hodgins. Construction and optimal search of interpolated motion graphs. ACM Transactions on Graphics,2007,26(3), Article 106,11 pages, DOI:10.1145/1239451.1239557
[51]J. McCann, N. Pollard. Responsive characters from motion fragments. ACM Transactions on Graphics, (SIGGRAPH 2007),2007,26(3), Article 6,7 pages, DOI:10.1145/1239451.1239457
[52]A. Treuille, Y. Lee, Z. Popovic. Near-optimal character animation with continuous control. ACM Transactions on Graphics,2007,26(3), Article 7,7 pages, DOI: 10.1145/1239451.1239458
[53]肖俊,庄越挺,吴飞.三维人体运动特征可视化与交互式运动分割.软件学报,2008,19(8)：1995-2003
[54]X. Cheng, G. D. Liu, Z. G. Pan, et al. Fragment based responsive character motion for interactive games. The Visual Computer,2009,25(5-7):479-485
[55]贺怀清,洪炳熔.一种虚拟人运动拟合算法.电子学报,2001,29(8)：1107-1109
[56]庄越挺,刘小明,潘云鹤.一种基于视频的人体动画骨架提取技术.计算机研究与发展,2000,37(4)：498-506
[57]L. Kovar, M. Gleicher, F. E. Pighin. Motion graphs. ACM Transactions on Graphics,2002,21 (3):473-482
[58]K. Yin, S. Coros, P. Beaudoin, et al. Continuation methods for adapting simulated skills. ACM Transactions on Graphics,2008,27(3):1-7
[59]王兆其.虚拟人合成研究综述.中国科学院研究生院学报,2000,17(2)：89-98
[60]罗忠祥,庄越挺,刘丰等.基于时空约束的运动编辑和运动重定向.计算机辅助设计与图形学学报,2002,14(12)：1146-1151
[61]T. Komura, H. Leung, J. Kuffner. Animating reactive motions for biped locomotion. In:The 2004 ACM Symposium on Virtual Reality Software and Technology (VRST'04), Hong Kong, ACM, New York, NY,2004:32-40
[62]O. Arikan, D. A. Forsyth, J. F. O'Brien. Pushing people around. In:The 2005 ACM SIGGRAPH/Eurographics Symposium on Computer Animation (SCA'05), Los Angeles, California, ACM, New York, NY,2005:59-66
[63]K. Yin, D.K. Pa, M.V. D. Panne. Data-driven interactive balancing behaviors. In: The 2005 Pacific Graphics, Macao, China,2005:118-120
[64]P. Faloutsos, M. V. D. Panne, D. Terzopoulos. The virtual stuntman:dynamic characters with a repertoire of autonomous motor skills. Computers & Graphics, 2001,25(6):933-953
[65]A. Moravanszky. NovodeX physics SDK. http://www.ageia.com,2007-2-27
[66]M. Mandel. Versatile and interactive virtual humans:hybrid use of data-driven and dynamics-based motion synthesis. Carnegie Mellon University,2004
[67]纪习尚,宫宁生,朱梧榴.基于最优分类面的神经网络模式分类方法.计算机工程,2006,32(22)：206-209
[68]唐冰.反应跟随性人体动画生成研究.浙江大学博士论文,2006
[69]L. H. Pang, Y. S. Tan, C. F. Wong, et al. ODECAL:A flexible open source rag doll simulation engine. Technologies for E-Learning and Digital Entertainment,2006, LNCS 3942:680-687
[70]M. B. Sabick, J. G. Hay, S. A. Banks. Active response decrease impact forces at the hip and shoulder in falls to the side. Journal of Biomechanics,1999,32(9): 993-998
[71]F. Fabio, N. R. Stephen. Reducing hip fracture risk during sideways falls: evidence in young adults of the protective effects of impact to the hands and stepping. Journal of Biomechanics,2007,40(9):2612-2618
[72]M. Vukobratovic, B. Borovac, D. Surdilovic. Zero-moment point proper interpretation and new application. IEEE/RAS International Conference on Humanoid Robots,2001:237-244
[73]刘莉,汪劲松,陈恳等.基于六维力/力矩传感器的拟人机器人实际ZMP检测.机器人,2001,23(5)：459-466
[74]M. Oshita, A. Makinouchi. A dynamic motion control technique for human-like articulated figures. Eurographics 2001,20(3):192-202
[75]Y. C. Pai, J. Patton. Center of mass velocity-position predictions for balance control. Journal of Biomechanics,1997,30(4):347-154
[76]E. T. Hsiao, S. N. Robinovitch. Biomechanical influences on balance recovery by stepping. Journal of Biomechanics,1999,32(4):1099-1106
[77]M. Wu, L. H. Ji, D. W. Jin, et al. Minimal step length necessary for recovery of forward balance loss with a single step. Journal of Biomechanics,2007,40(9): 1559-1566
[78]武明,季林红,金德闻等.人体站立受扰平衡策略的实验研究.清华大学学报(自然科学版),2003,43(2)：152-155
[79]N. R. Stephen, B. Rebecca, M. Jessica. Effect of the squat protective response on impact velocity during backward falls. Journal of Biomechanics,2004,37(9): 1329-1337
[80]A. L. Hof, M. G. J. Gazendam, W. E. Sinke. The condition for dynamic stability. Journal of Biomechanics,2005,38(9):1-8
[81]S. L. Delp, J. P. Loan, M. G. Hoy, et al. An interactive graphics-based model of the lower extremity to study orthopaedic surgical procedures. IEEE Transactions on Biomedical Engineering,1990,37(8):757-767
[82]R. C. Miall, D. J. Weir, D. M. Wolpert, et al. Is the cerebellum a smith predictor? Journal of Motor Behaviour,1993,25(3):203-216
[83]S. Arya, D. Mount. Approximate nearest neighbor queries in fixed dimensions. In: Proceedings of the Fourth Annual ACM-SIAM Symposium on Discrete Algorithms, Austin, Texas, United States, Society for Industrial and Applied Mathematics, Philadelphia, PA,1993:271-280
[84]J. Lee, S. Y. Shin. A hierarchical approach to interactive motion editing for humanlike figures. In:The 26th Annual Conference on Computer Graphics and Interactive Techniques, ACM Press/Addison-Wesley Publishing Co., New York, NY,1999:39-48
[85]N. Thalmann, D. Thalmann. Virtual humans:thirty years of research, what next? The Visual Computer,2005,21(12):997-1015
[86]刘莉,王兆其,朱登明等.基于运动轨迹重构的运动编辑.计算机辅助设计与图形学学报,2006,18(10)：1613-1618
[87]D. M. Zhu, Z. Q. Wang, S. H. Xia. Motion editing with the state feedback dynamic model. In:Computer Graphics International (CGI'06), Hangzhou, China, LNCS 4035,2006:348-359
[88]M. Gleicher, H. J. Shin, L. Kovar, et al. Snap-together motion:assembling run-time animations. ACM Transactions on Graphics,2003,22(3):181-188
[89]O. Arikan, D. A. Forsyth. Interactive motion generation from examples. ACM Transactions on Graphics,2002,21(3):483-490
[90]R. Heck, M. Gleicher. Parametric motion graphs. In:Proceedings of the 2007 Symposium on Interactive 3D Graphics and Games (I3D'07), Seattle, Washington, ACM, New York, NY,2007:129-136
[91]K. Pullen, C. Bregler. Motion capture assisted animation:texturing and synthesis. In:Proceedings of the 29th Annual Conference on Computer Graphics and Interactive Techniques (SIGGRAPH'02), San Antonio, Texas, ACM, New York, NY,2002:501-508.
[92]A. Schodl, I. Essa. A machine learning for video based rendering technical report. GIT-GVU-00-11, Georgia Institute of Technology,2000
[93]O. Arikan, D. A. Forsyth, J. F. O'brien. Motion synthesis from annotations. ACM Transactions on Graphics,2003,22(3):402-408
[94]J. Chai, J. K. Hodgins. Performance animation from low-dimensional control signals. ACM Transactions on Graphics,2005,24(3):686-696
[95]V. B. Zordan, A. Macchietto, J. Medina, et al. Interactive dynamic response for games. In:Proceedings of the 2007 ACM SIGGRAPH Symposium on Video Games (Sandbox'07), San Diego, California, ACM, New York, NY,2007:9-14
[96]J. Lee, J Chai, P. S. A. Reitsma, et al. Interactive control of avatars animated with human motion data. ACM Transactions on Graphics,2002,21(3):491-500
[97]T. Kwon, S. Y. Shin. Motion modeling for on-line locomotion synthesis. In:ACM SIGGRAPH/Eurographics Symposium on Computer Animation (SCA'05), Los Angeles, California, ACM, New York, NY,2005:29-38
[98]K. H. Lee, M. G. Choi, J. Lee. Motion patches:Building blocks for virtual environments annotated with motion data. ACM Transactions on Graphics,2006, 25(3):898-906
[99]M. G. Choi, J. Lee, S. Y. Shin. Planning biped locomotion using motion capture data and probabilistic roadmaps. ACM Transactions on Graphics,2003,22(2): 182-203
[100]A. C. Fang, N. S. Pollard. Efficient synthesis of physically valid human motion. ACM Transactions on Graphics,2003,22(3):417-426
[101]M. Sung, L. Kovar, M. Gleicher. Fast and accurate goal-directed motion synthesis for crowds. In:Proceedings of the 2005 ACM SIGGRAPH/Eurographics Symposium on Computer Animation (SCA'05), Los Angeles, California, ACM, New York, NY,2005:291-300
[102]J. Lee, K. H. Lee. Pre-computing avatar behavior from human motion data. Graphics Models,2006,68(2):158-174
[103]M. Lau, J. Kuffher. Pre-computed search trees:planning for interactive goal-driven animation. In:Proceedings of the 2006 ACM SIGGRAPH Eurographics Symposium on Computer Animation, Vienna, Austria, Eurographics Association, Aire-la-Ville, Switzerland,2006:299-308
[104]S. I. Park, H. J. Shin, S. Y. Shin. On-line locomotion generation based on motion blending. In:ACM SIGGRAPH/Eurographics Symposium on Computer Animation (SCA'02), San Antonio, Texas, ACM, New York, NY,2002:105-112
[105]S. I. Park, H. J. Shin, T. H. Kim, et al. Online motion blending for real-time locomotion generation. Computer Animation and Virtual Worlds,2004,15(3-4): 125-138
[106]H. J. Shin, H. S. Oh. Fat graphs:constructing an interactive character with continuous controls. In:ACM SIGGRAPH/Eurographics Symposium on Computer Animation, Vienna, Austria, Eurographics Association, Aire-la-Ville, Switzerland,2006:291-298
[107]L. P. Kaelbling, M. L. Littman, A. W. Moore. Reinforcement learning:a survey. Journal of Artifcial Intelligence Research,1996, Vol 4:237-285
[108]C. G. Atkeson, A. W. Moore, S. Schaal. Locally weighted learning for control. Artificial Intelligence Review,1997,11(1-5):75-113
[109]D. P. Bertsekas. Dynamic Programming and Optimal Control. Athena Scientific, 2001
[110]D. Farias. The linear programming approach to approximate dynamic programming:theory and application. PhD thesis, Stanford University,2002
[111]S. M. Lavalle. Planning algorithms. Cambridge University Press,2006