Flipping with physics: motion editing for acrobatics

ABSTRACT

Complex acrobatic stunts, such as double or triple flips, can be performed only by highly skilled athletes. On the other hand, simpler tricks, such as single-flip jumps, are relatively easy to master. We present a method for creating complex, multi-flip ballistic motions from simple, single-flip jumps. Our approach also allows an animator to interact with the system by introducing modifications to a ballistic phase of a motion. Our method automatically adjusts motion trajectories, to assure physical validity of the motion after the modifications. The presented technique is efficient and produces physically valid results without resorting to computationally expensive optimization. To validate our approach we present the results of a study of user sensitivity to errors in angular momentum and take-off angle. The study shows that small changes of these parameters introduced by our method are not perceptible to a viewer.

REFERENCES

• 1: Okan Arikan , D. A. Forsyth, Interactive motion generation from examples, Proceedings of the 29th annual conference on Computer graphics and interactive techniques, July 23-26, 2002, San Antonio, Texas
• 2: Yeuhi Abe , C. Karen Liu , Zoran Popović, Momentum-based parameterization of dynamic character motion, Graphical Models, v.68 n.2, p.194-211, March 2006 [doi>10.1016/j.gmod.2005.03.006]
• 3: {Bel} Bell R.:. Personal communication. Gymnastic coach and competition judge, Olympic gymnast.
• 4: {BL06} Bridgett L., Linthorne N.: Changes in long jump take-off technique with increasing run-up speed. Journal of Sports Sciences 24, 8 (2006), 889--897.
• 5: Kiran S. Bhat , Steven M. Seitz , Jovan Popovic, Computing the Physical Parameters of Rigid-Body Motion from Video, Proceedings of the 7th European Conference on Computer Vision-Part I, p.551-565, May 28-31, 2002
• 6: {CM69} Clauser C. E., McConville J. T.: Weight, Volume, and Center of Mass of Segments of the Human Body. National Technical Information Service, 1969.
• 7: {cmu} CMU graphics lab motion capture database. http://mocap.cs.cmu.edu/.
• 8: {DG67} Dempster W. T., Gaughran G. R. L.: Properties of body segments based on size and weight. American Journal of Anatomy 120, 1 (1967), 33--54.
• 9: Anthony C. Fang , Nancy S. Pollard, Efficient synthesis of physically valid human motion, ACM SIGGRAPH 2003 Papers, July 27-31, 2003, San Diego, California
• 10: {FvdPT01} Faloutsos P., van de Panne M., Terzopoulos D.: The virtual stuntman: dynamic characters with a repertoire of autonomous motor skills. Computers and Graphics 25, 6 (2001), 933--953.
• 11: Jessica K. Hodgins , Wayne L. Wooten , David C. Brogan , James F. O'Brien, Animating human athletics, Proceedings of the 22nd annual conference on Computer graphics and interactive techniques, p.71-78, September 1995 [doi>10.1145/218380.218414]
• 12: Lucas Kovar , Michael Gleicher , Frédéric Pighin, Motion graphs, Proceedings of the 29th annual conference on Computer graphics and interactive techniques, July 23-26, 2002, San Antonio, Texas
• 13: {KY03} King M. A., Yeadon M. R.: Coping with perturbations to a layout somersault in tumbling. Journal of Biomechanics 36, 7 (2003), 921--927.
• 14: {KY04} King M. A., Yeadon M. R.: Maximising somersault rotation in tumbling. Journal of Biomechanics 37, 4 (2004), 471--477.
• 15: Jehee Lee , Jinxiang Chai , Paul S. A. Reitsma , Jessica K. Hodgins , Nancy S. Pollard, Interactive control of avatars animated with human motion data, Proceedings of the 29th annual conference on Computer graphics and interactive techniques, July 23-26, 2002, San Antonio, Texas
• 16: Zicheng Liu , Steven J. Gortler , Michael F. Cohen, Hierarchical spacetime control, Proceedings of the 21st annual conference on Computer graphics and interactive techniques, p.35-42, July 1994 [doi>10.1145/192161.192169]
• 17: C. Karen Liu , Aaron Hertzmann , Zoran Popović, Learning physics-based motion style with nonlinear inverse optimization, ACM SIGGRAPH 2005 Papers, July 31-August 04, 2005, Los Angeles, California
• 18: C. Karen Liu , Zoran Popović, Synthesis of complex dynamic character motion from simple animations, Proceedings of the 29th annual conference on Computer graphics and interactive techniques, July 23-26, 2002, San Antonio, Texas
• 19: Joseph Laszlo , Michiel van de Panne , Eugene Fiume, Interactive control for physically-based animation, Proceedings of the 27th annual conference on Computer graphics and interactive techniques, p.201-208, July 2000 [doi>10.1145/344779.344876]
• 20: J. McCann , N. S. Pollard , S. Srinivasa, Physics-based motion retiming, Proceedings of the 2006 ACM SIGGRAPH/Eurographics symposium on Computer animation, September 02-04, 2006, Vienna, Austria
• 21: {Nel} Nelson M.:. Personal communication. Gymnastic coach, former gymnast (three-time NCAA champion).
• 22: Carol O'Sullivan , John Dingliana , Thanh Giang , Mary K. Kaiser, Evaluating the visual fidelity of physically based animations, ACM SIGGRAPH 2003 Papers, July 27-31, 2003, San Diego, California
• 23: {PA00} Pandy M. G., Anderson F. C.: Dynamic simulation of human movement using large-scale models of the body. In Proc. IEEE Intl. Conference on Robotics and Automation (2000), pp. 676--681.
• 24: Charles Rose , Brian Guenter , Bobby Bodenheimer , Michael F. Cohen, Efficient generation of motion transitions using spacetime constraints, Proceedings of the 23rd annual conference on Computer graphics and interactive techniques, p.147-154, August 1996 [doi>10.1145/237170.237229]
• 25: Paul S. A. Reitsma , Nancy S. Pollard, Perceptual metrics for character animation: sensitivity to errors in ballistic motion, ACM SIGGRAPH 2003 Papers, July 27-31, 2003, San Diego, California
• 26: {SBvL00} Seyfarth A., Blickhan R., van Leeuwen J. L.: Optimum take-off techniques and muscle design for long jump. J. Exp. Biol 203 (2000), 741--750.
• 27: Alla Safonova , Jessica K. Hodgins, Analyzing the physical correctness of interpolated human motion, Proceedings of the 2005 ACM SIGGRAPH/Eurographics symposium on Computer animation, July 29-31, 2005, Los Angeles, California [doi>10.1145/1073368.1073392]
• 28: Alla Safonova , Jessica K. Hodgins , Nancy S. Pollard, Synthesizing physically realistic human motion in low-dimensional, behavior-specific spaces, ACM SIGGRAPH 2004 Papers, August 08-12, 2004, Los Angeles, California
• 29: Adnan Sulejmanpašić , Jovan Popović, Adaptation of performed ballistic motion, ACM Transactions on Graphics (TOG), v.24 n.1, p.165-179, January 2005 [doi>10.1145/1037957.1037966]
• 30: {V-F59} V-Five Association of America: Gymnastics and tumbling, prepared by Hartley D. Price {and others} for the V-Five Association of America. Annapolis: United States Naval Institute, 1959.
• 31: {WH00} Wooten W. L., Hodgins J. K.: Simulating leaping, tumbling, landing, and balancing humans. In ICRA (2000), pp. 656--662.
• 32: Andrew Witkin , Michael Kass, Spacetime constraints, Proceedings of the 15th annual conference on Computer graphics and interactive techniques, p.159-168, June 1988
• 33: Victor Brian Zordan , Anna Majkowska , Bill Chiu , Matthew Fast, Dynamic response for motion capture animation, ACM SIGGRAPH 2005 Papers, July 31-August 04, 2005, Los Angeles, California
• 34: Peng Zhao , Michiel van de Panne, User interfaces for interactive control of physics-based 3D characters, Proceedings of the 2005 symposium on Interactive 3D graphics and games, April 03-06, 2005, Washington, District of Columbia [doi>10.1145/1053427.1053441]

INDEX TERMS

Primary Classification:
  I. Computing Methodologies
  I.3 COMPUTER GRAPHICS
      I.3.7 Three-Dimensional Graphics and Realism