## Virtual Wind-up Toys for Animation (1994)

Venue: | Proceedings of Graphics Interface '94 |

Citations: | 32 - 9 self |

### BibTeX

@INPROCEEDINGS{Panne94virtualwind-up,

author = {Michiel van de Panne and Ryan Kim and Eugene Flume},

title = {Virtual Wind-up Toys for Animation},

booktitle = {Proceedings of Graphics Interface '94},

year = {1994},

pages = {208--215}

}

### Years of Citing Articles

### OpenURL

### Abstract

We propose a new method of automatically finding periodic modes of locomotion for arbitrary articulated figures. Cyclic pose control graphs are used as our control representation. These specifically constrain the controller synthesis process to only those controllers producing periodic driving functions. It is shown that stochastic generate-and-test techniques work well with this representation. Several choices that arise in this synthesis technique are explored. The impact of the design of the physical models upon the motions produced is examined. Lastly, the motions produced are analysed by looking at their bifurcation diagrams. Keywords: animation, control, simulation, locomotion, modelling, limit cycles Résumé Nous présentons une nouvelle méthode permettant de trouver automatiquement des mouvement periodiques pour des figures articulées. Nous utilisons des réseaux cycliques de poses pour représenter et contrôler les mouvements. Ces réseaux contraignent la synthèse des contr ôleu...

### Citations

315 | Spacetime constraints
- Witkin, Kass
- 1988
(Show Context)
Citation Context ...onent, which is an impediment to the application of these control techniques to arbitrary systems. Optimization techniques provide some promise of automating the design of controllers. Witkin and Kass=-=[19]-=- (and later expanded upon by Cohen[3]) propose a powerful technique for optimizing motions as trajectories over time. One restriction of dealing with motions as trajectories is that it is difficult to... |

272 |
Passive dynamic walking
- McGeer
- 1990
(Show Context)
Citation Context ...nvironment in order to reach a steady-state periodic motion or limit cycle. The tendency of some mechanical systems to reach periodic limit cycles has been used in the past as a useful design property=-=[8]-=-. Many non-linear dynamical systems are liable to bifurcations and chaotic motions, however, and the creatures we are dealing with here prove to be no exception. Some interesting previous work on bifu... |

153 |
Interactive spacetime control for animation
- Cohen
- 1992
(Show Context)
Citation Context ...pplication of these control techniques to arbitrary systems. Optimization techniques provide some promise of automating the design of controllers. Witkin and Kass[19] (and later expanded upon by Cohen=-=[3]-=-) propose a powerful technique for optimizing motions as trajectories over time. One restriction of dealing with motions as trajectories is that it is difficult to properly incorporate interactions wi... |

147 |
Animation of dynamic legged locomotion
- Raibert, Hodgins
- 1991
(Show Context)
Citation Context ...es of hand-programmed controllers have also had success in controlling periodic motions. Raibert and Hodgins present an elegant method for controlling periodic hopping gaits for a variety of creatures=-=[13]-=-. Stewart and Cremer present a walking controller based upon the addition and removal of constraints[14]. Bruderlin and Calvert construct a walking controller by applying knowledge of the state-phase ... |

96 | Sensor-actuator networks
- Panne, Fiume
- 1993
(Show Context)
Citation Context ...hether a given parameter change contributes towards a desired behaviour or not. Two variations on this type of approach were investigated independently by Ngo and Marks[11], and van de Panne and Fiume=-=[17]-=-. The algorithm is perhaps best called generate-and-test when controller parameters are chosen completely at random, and modify-and-test when modifications are being made to an initial set of paramete... |

83 |
Analysis of a simplified hopping robot
- Koditschek, Biihler
- 1991
(Show Context)
Citation Context ... however, and the creatures we are dealing with here prove to be no exception. Some interesting previous work on bifurcations and chaotic motion analysis exists for simplified models of hopping robots=-=[7]-=-[15]. We shall use the transition time between two states of a pose-control graph as a bifurcation parameter to illustrate the various types of motion that can result from a single pose-control graphs... |

82 |
The motion dynamics of snakes and worms
- Miller
- 1988
(Show Context)
Citation Context ...tructing controllers that explicitly produce periodic outputs. Miller used periodic sinusoidal contractions and expansions to obtain modes of locomotion for physically-based models of worms and snakes=-=[10]-=-. McKenna and Zeltzer used a set of coordinated periodic motions to obtain robust walking motions for a model of a cockroach[9]. Van de Panne, Fiume, and Vranesic use variations of periodic control to... |

68 |
Dynamic simulation of autonomous legged locomotion
- McKenna, Zeltzer
- 1990
(Show Context)
Citation Context ...tain modes of locomotion for physically-based models of worms and snakes[10]. McKenna and Zeltzer used a set of coordinated periodic motions to obtain robust walking motions for a model of a cockroach=-=[9]-=-. Van de Panne, Fiume, and Vranesic use variations of periodic control to balance and steer turning figures[18]. The technique in this paper presents a way of automating the synthesis of periodic cont... |

49 |
Elastic mechanisms in animal movement
- Alexander
- 1988
(Show Context)
Citation Context ... graph was designed. speed energy metric mechanical work at passive joints | 0.0 | 0.1 | 0.2 | 0.3 | 0.4 | 0.5 | 0.0 | 0.5 | 1.0 | 1.5 kP (N/m) normalized values k p 0.1 < in obtaining natural motions=-=[1]-=-. In general, the motions produced using optimization methods are an equal product of the physical model, the optimization metric used, and the search strategy. 5 Motion Analysis Do cyclic pose-contro... |

32 | An Optimal Control Model for MaximumHeight Human Jumping - Pandy, Zajac - 1990 |

31 |
Controlling dynamic simulation with kinematic constraints, behavior functions and inverse dynamics
- Issacs, Cohen
- 1987
(Show Context)
Citation Context ...he addition and removal of constraints[14]. Bruderlin and Calvert construct a walking controller by applying knowledge of the state-phase timing[2]. We also build on the early ideas of Isaac and Cohen=-=[6]-=-. The controllers outlined above have a large hand-designed component, which is an impediment to the application of these control techniques to arbitrary systems. Optimization techniques provide some ... |

31 | Beyond Keyframing: An Algorithmic Approach to Animation
- Stewart, Cremer
- 1992
(Show Context)
Citation Context ...gins present an elegant method for controlling periodic hopping gaits for a variety of creatures[13]. Stewart and Cremer present a walking controller based upon the addition and removal of constraints=-=[14]-=-. Bruderlin and Calvert construct a walking controller by applying knowledge of the state-phase timing[2]. We also build on the early ideas of Isaac and Cohen[6]. The controllers outlined above have a... |

29 | Reusable Motion Synthesis using StateSpace Controllers
- Panne, Fiume, et al.
- 1990
(Show Context)
Citation Context ...se caused by impact with the ground, pose difficulties for many optimization techniques. Other optimal control techniques have also been applied by Girard[4], Pandy et al.[12], and van de Panne et al.=-=[16]-=-. The size of the search space of most optimization techniques tends to grow quickly as a function of the complexity of the object. An alternative approach is to use a generate-and-test optimization p... |

21 |
Generating Natural-looking Motion for Computer Animation
- Hodgins, Sweeney, et al.
- 1992
(Show Context)
Citation Context ...igures[18]. The technique in this paper presents a way of automating the synthesis of periodic controllers. The work presented in this paper builds on some of the ideas presented by Hodgins et al. in =-=[5]-=-. In this work, state-machines are used to implicitly specify periodic motions, including riding a see-saw, pumping a swing, and juggling three balls in various patterns. Other types of hand-programme... |

18 |
An `interesting' strange attractor in the dynamics of a hopping robot
- Vakakis, Burdick, et al.
- 1991
(Show Context)
Citation Context ...wever, and the creatures we are dealing with here prove to be no exception. Some interesting previous work on bifurcations and chaotic motion analysis exists for simplified models of hopping robots[7]=-=[15]-=-. We shall use the transition time between two states of a pose-control graph as a bifurcation parameter to illustrate the various types of motion that can result from a single pose-control graphs. An... |

15 |
Goal-directed animation of human walking
- Bruderlin, Calvert
- 1989
(Show Context)
Citation Context ...art and Cremer present a walking controller based upon the addition and removal of constraints[14]. Bruderlin and Calvert construct a walking controller by applying knowledge of the state-phase timing=-=[2]-=-. We also build on the early ideas of Isaac and Cohen[6]. The controllers outlined above have a large hand-designed component, which is an impediment to the application of these control techniques to ... |

11 |
Constrained optimization of articulated animal movement in computer animation
- Girard
- 1991
(Show Context)
Citation Context ...nt. Discontinuities in the motion, such as those caused by impact with the ground, pose difficulties for many optimization techniques. Other optimal control techniques have also been applied by Girard=-=[4]-=-, Pandy et al.[12], and van de Panne et al.[16]. The size of the search space of most optimization techniques tends to grow quickly as a function of the complexity of the object. An alternative approa... |

5 |
Spacetime Constraints Revisitied
- Ngo, Marks
- 1993
(Show Context)
Citation Context ... can then be used to determine whether a given parameter change contributes towards a desired behaviour or not. Two variations on this type of approach were investigated independently by Ngo and Marks=-=[11]-=-, and van de Panne and Fiume[17]. The algorithm is perhaps best called generate-and-test when controller parameters are chosen completely at random, and modify-and-test when modifications are being ma... |

5 | PhysicallyBased Modeling and Control of Turning - Panne, Fiume, et al. - 1993 |