Spacetime constraints revisited

The Spacetime Constraints (SC) paradigm, whereby the animator specifies what an animated figure should do but not how to do it, is a very appealing approach to animation. However, the algorithms available for realizing the SC approach are limited. Current techniques are local in nature: they all use some kind of perturbational analysis to refine an initial trajectory. We propose a global search algorithm that is capable of generating multiple novel trajectories for SC problems from scratch. The key elements of our search strategy are a method for encoding trajectories as behaviors, and a genetic search algorithm for choosing behavior parameters that is currently implemented on a massively parallel computer. We describe the algorithm and show computed solutions to SC problems for 2D articulated figures. CR Categories: I.2.6 [Artificial Intelligence]: Learning— parameter learning. I.2.6 [Artificial Intelligence]: Problem Solving, Control Methods and Search—heuristic methods. I.3.7 [Computer Graphics]: Three-Dimensional Graphics and Realism— animation. I.6.3 [Simulation and Modeling]: Applications. Additional

[1]  R. M. Elliott.  The Century psychology series , 1959 .

[2]  John H. Holland,et al.  Adaptation in Natural and Artificial Systems: An Introductory Analysis with Applications to Biology, Control, and Artificial Intelligence , 1992 .

[3]  Kenneth Alan De Jong,et al.  An analysis of the behavior of a class of genetic adaptive systems. , 1975 .

[4]  J. Y. S. Luh,et al.  On-Line Computational Scheme for Mechanical Manipulators , 1980 .

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

[6]  Arun N. Netravali,et al.  Motion interpolation by optimal control , 1988, SIGGRAPH.

[7]  David E. Goldberg,et al.  Genetic Algorithms in Search Optimization and Machine Learning , 1988 .

[8]  James K. Hahn,et al.  Realistic animation of rigid bodies , 1988, SIGGRAPH.

[9]  Gilbert Syswerda,et al.  Uniform Crossover in Genetic Algorithms , 1989, ICGA.

[10]  Rodney A. Brooks,et al.  Learning to Coordinate Behaviors , 1990, AAAI.

[11]  Lawrence. Davis,et al.  Handbook Of Genetic Algorithms , 1990 .

[12]  Jane Wilhelms,et al.  A 'Notion' for interactive behavioral animation control , 1990, IEEE Computer Graphics and Applications.

[13]  David Baraff,et al.  Coping with friction for non-penetrating rigid body simulation , 1991, SIGGRAPH.

[14]  Nostrand Reinhold,et al.  the utility of using the genetic algorithm approach on the problem of Davis, L. (1991), Handbook of Genetic Algorithms. Van Nostrand Reinhold, New York. , 1991 .

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