Perception Based Real-Time Dynamic Adaptation of Human Motions

This paper presents a new real-time method for dynamics-based animation of virtual characters. It is based on rough physical approximations that lead to natural-looking and physically realistic human motions. The first part of this work consists in evaluating the relevant parameters of natural motions performed by people subject to various external perturbations. According to this pilot study, we have defined a method that is able to adapt in real-time the motion of a virtual character in order to satisfy kinematic and dynamic constraints, such as pushing, pulling and carrying objects with more or less mass. This method relies on laws provided by experimental studies that enable us to avoid using complex mechanical models and thus save computation time. One of the most important assumption consists in decoupling the pose of character and the timing of the motion. Thanks to this method, it is possible to animate up to 15 characters at 60Hz while dealing with complex kinematic and dynamic constraints.

[1]  Jessica K. Hodgins,et al.  Synthesizing physically realistic human motion in low-dimensional, behavior-specific spaces , 2004, SIGGRAPH 2004.

[2]  C. K. Liu,et al.  Learning physics-based motion style with nonlinear inverse optimization , 2005, SIGGRAPH 2005.

[3]  Taku Komura,et al.  Animating reactive motion using momentum‐based inverse kinematics , 2005, Comput. Animat. Virtual Worlds.

[4]  M. V. D. Panne,et al.  SIMBICON: simple biped locomotion control , 2007, SIGGRAPH 2007.

[5]  Nancy S. Pollard,et al.  Efficient synthesis of physically valid human motion , 2003, ACM Trans. Graph..

[6]  David A. Forsyth,et al.  Pushing people around , 2005, SCA '05.

[7]  Jessica K. Hodgins,et al.  Simulating balance recovery responses to trips based on biomechanical principles , 2009, SCA '09.

[8]  Hyun Joon Shin,et al.  Physical touch-up of human motions , 2003, 11th Pacific Conference onComputer Graphics and Applications, 2003. Proceedings..

[9]  Hyeong-Seok Ko,et al.  A physically-based motion retargeting filter , 2005, TOGS.

[10]  Geoffrey P. Bingham.  Kinematic Form and Scaling: Further Investigations on the Visual Perception of Lifted Weight , 1987 .

[11]  Petros Faloutsos,et al.  The virtual stuntman: dynamic characters with a repertoire of autonomous motor skills , 2001, Comput. Graph..

[12]  Victor B. Zordan,et al.  Dynamic response for motion capture animation , 2005, SIGGRAPH 2005.

[13]  Thanh Giang,et al.  Evaluating the visual fidelity of physically based animations , 2003, ACM Trans. Graph..

[14]  C. Karen Liu,et al.  Synthesis of complex dynamic character motion from simple animations , 2002, ACM Trans. Graph..

[15]  Petros Faloutsos,et al.  Flipping with physics: motion editing for acrobatics , 2007, SCA '07.

[16]  David C. Brogan,et al.  Animating human athletics , 1995, SIGGRAPH.

[17]  Petros Faloutsos,et al.  Composable controllers for physics-based character animation , 2001, SIGGRAPH.

[18]  Jessica K. Hodgins,et al.  Motion capture-driven simulations that hit and react , 2002, SCA '02.

[19]  Andrew P. Witkin,et al.  Spacetime constraints , 1988, SIGGRAPH.

[20]  Victor B. Zordan,et al.  Momentum control for balance , 2009, SIGGRAPH 2009.

[21]  Makoto Sato,et al.  Physics‐driven Multi Dimensional Keyframe Animation for Artist‐directable Interactive Character , 2009, Comput. Graph. Forum.

[22]  A. Hof.  The equations of motion for a standing human reveal three mechanisms for balance. , 2007, Journal of biomechanics.

[23]  Taku Komura,et al.  Animating reactive motion using momentum-based inverse kinematics: Motion Capture and Retrieval , 2005 .

[24]  Bruno Arnaldi,et al.  Morphology‐independent representation of motions for interactive human‐like animation , 2005, Comput. Graph. Forum.

[25]  Katsu Yamane,et al.  Dynamics Filter - concept and implementation of online motion Generator for human figures , 2000, IEEE Trans. Robotics Autom..

[26]  Michael F. Cohen,et al.  Interactive spacetime control for animation , 1992, SIGGRAPH.

[27]  Glenn Reinman,et al.  Fool me twice: Exploring and exploiting error tolerance in physics-based animation , 2009, TOGS.

[28]  Taku Komura,et al.  Can we distinguish biological motions of virtual humans?: perceptual study with captured motions of weight lifting , 2010, VRST '10.

[29]  S. Runeson,et al.  Visual perception of lifted weight. , 1981, Journal of experimental psychology. Human perception and performance.