“Interactive manipulation of rigid body simulations” by Popović, Seitz, Erdmann, Popovic and Witkin

Physical simulation of dynamic objects has become commonplace in computer graphics because it produces highly realistic animations. In this paradigm the animator provides few physical parameters such as the objects’ initial positions and velocities, and the simulator automatically generates realistic motions. The resulting motion, however, is difficult to control because even a small adjustment of the input parameters can drastically affect the subsequent motion. Furthermore, the animator often wishes to change the end-result of the motion instead of the initial physical parameters.
We describe a novel interactive technique for intuitive manipulation of rigid multi-body simulations. Using our system, the animator can select bodies at any time and simply drag them to desired locations. In response, the system computes the required physical parameters and simulates the resulting motion. Surface characteristics such as normals and elasticity coefficients can also be automatically adjusted to provide a greater range of feasible motions, if the animator so desires. Because the entire simulation editing process runs at interactive speeds, the animator can rapidly design complex physical animations that would be difficult to achieve with existing rigid body simulators.

1. David Baraff. Fast Contact Force Computation for Nonpenetrating Rigid Bodies. In Computer Graphics (Proceedings of SIGGRAPH 94), Annual Conference Series, pages 23-34. ACM SIGGRAPH, July 1994.
2. David Baraff and Andrew Witkin. Large Steps in Cloth Simulation. In Computer Graphics (Proceedings of SIGGRAPH 98), Annual Conference Series, pages 43-54. ACM SIG- GRAPH, July 1998.
3. Ronen Barzel and Alan H. Barr. A Modeling System Based On Dynamic Constraints. In Computer Graphics (Proceedings of SIGGRAPIt 87), Annual Conference Series, pages 179-188. ACM SIGGRAPH, August 1988.
4. Ronen Barzel, John F. Hughes, and Daniel N. Wood. Plausible Motion Simulation for Computer Graphics Animation. In Computer Animation and Simulation ’96, Proceedings of the Eurographics Workshop, pages 184-197, Poitiers, France, September 1996.
5. Dimitri R Bertsekas. Nonlinear Programming. Athena Scientific, Belmont, Massachusetts, 1995.
6. Lynne Shapiro Brotman and Arun N. Netravali. Motion Interpolation by Optimal Control. In Computer Graphics (Proceedings of SIGGRAPH 88), volume 26 of Annual Conference Series, pages 309-315. ACM SIGGRAPH, August 1988.
7. Stephen Chenney and D. A. Forsyth. Sampling Plausible Solutions to Multi-body Constraint Problems. In Computer Graphics (Proceedings of SIGGRAPH 2000), Annual Conference Series. ACM SIGGRAPH, July 2000.
8. Michael F. Cohen. Interactive Spacetime Control for Animation. In Computer Graphics (Proceedings of SIGGRAPH 92), Annual Conference Series, pages 293-302. ACM SIG- GRAPH, July 1992.
9. Bruce Donald, Patrick Xavier, John Canny, and John Reif. Kinodynamic Motion Planning. Journal of the ACM, 40(5): 1048-1066, November 1993.
10. Nick Foster and Dimitri Metaxas. Realistic Animation of Liquids. Graphical Models and Image Processing, 5(58):471- 483, 1996.
11. Michael Garland and Paul S. Heckbert. Surface Simplification Using Quadric Error Metrics. In Computer Graphics (Proceedings of SIGGRAPH 97), Annual Conference Series, pages 209-216. ACM SIGGRAPH, August 1997.
12. Philip E Gill, Walter Murray, and Margaret H. Wright. Practical Optimization. Academic Press, London, 1989.
13. Michael Gleicher and Andrew Witkin. Differential Manipulation. In Graphics Interface, pages 61-67, June 1991.
14. Michael Gleicher and Andrew Witkin. Through-the-Lens Camera Control. In Computer Graphics (Proceedings of SIGGRAPH 92), Annual Conference Series, pages 331-340. ACM SIGGRAPH, July 1992.
15. F. Sebastian Grassia. Practical Parameterization of Rotation Using the Exponential Map. Journal of Graphics Tools, 3(3):29-48, 1998.
16. Radek Grzeszczuk, Demetri Terzopoulos, and Geoffrey Hinton. NeuroAnimator: Fast Neural Network Emulation and Control of Physics-Based Models. In Computer Graphics (Proceedings of SIGGRAPH 98), Annual Conference Series, pages 9-20. ACM SIGGRAPH, July 1998.
17. Mikako Harada, Andrew Witkin, and David Baraff. Interactive Physically-Based Manipulation of Discrete/Continuous Models. In Computer Graphics (Proceedings of SIGGRAPH 95), Annual Conference Series, pages 199-208. ACM SIG- GRAPH, August 1995.
18. Wilfred Kaplan. Advanced Calculus. Addison-Wesley Publishing Company, Reading, Massachusetts, 1984.
19. Zicheng Liu, Steven J. Gortler, and Michael F. Cohen. Hierarchical Spacetime Control. In Computer Graphics (Proceedings of SIGGRAPH 94), Annual Conference Series, pages 35- 42. ACM SIGGRAPH, July 1994.
20. Matthew Moore and Jane Wilhelms. Collision Detection and Response for Computer Animation. In Computer Graphics (Proceedings of SIGGRAPH 88), Annual Conference Series, pages 289-298. ACM SIGGRAPH, August 1988.
21. J. Thomas Ngo and Joe Marks. Spacetime Constraints Revisited. In Computer Graphics (Proceedings of SIGGRAPH 93), Annual Conference Series, pages 343-350. ACM SIG- GRAPH, August 1993.
22. James F. O’Brien and Jessica K. Hodgins. Graphical Modeling and Animation of Brittle Fracture. In Computer Graphics (Proceedings of SIGGRAPH 99), Annual Conference Series, pages 111-120. ACM SIGGRAPH, August 1999.
23. Zoran Popovid and Andrew Witkin. Physically Based Motion Transformation. In Computer Graphics (Proceedings of SIG- GRAPH 99), Annual Conference Series, pages 11-20. ACM SIGGRAPH, August 1999.
24. Jos Stam. Stable Fluids. In Computer Graphics (Proceedings of SIGGRAPH 99), Annual Conference Series, pages 121- 128. ACM SIGGRAPH, August 1999.
25. Robert F. Stengel. Optimal Control and Estimation. Dover Books on Advanced Mathematics, New York, 1994.
26. Keith R. Symon. Mechanics, Third Edition. Addison-Wesley Publishing Company, Reading, Massachussetts, 1971.
27. Diane Tang, J. Thomas Ngo, and Joe Marks. N-Body Spacetime Constraints. Journal of Visualization and Computer Animation, 6:143-154, 1995.
28. Andrew Witkin, Michael Gleicher, and William Welch. Interactive Dynamics. In Proceedings of the 1990 symposium on Interactive 3D graphics, pages 11-21, March 1990.
29. Andrew Witkin and Michael Kass. Spacetime Constraints. In Computer Graphics (Proceedings of SIGGRAPH 88), Annual Conference Series, pages 159-168. ACM SIGGRAPH, August 1988.