This paper describes algorithms for the animation of men and women performing three dynamic athletic behaviors: running, bicycling, and vaulting. We animate these behaviors using control algorithms that cause a physically realistic model to perform the desired maneuver. For example, control algorithms allow the simulated humans to maintain balance while moving their arms, to run or bicycle at a variety of speeds, and to perform a handspring vault. Algorithms for group behaviors allow a number of simulated bicyclists to ride as a group while avoiding simple patterns of obstacles. We add secondarymotion to the animations with springmass simulations of clothing driven by the rigid-body motion of the simulated human. For each simulation, we compare the computed motion to that of humans performing similar maneuvers both qualitatively through the comparison of real and simulated video images and quantitatively through the comparison of simulated and biomechanical data.

Abstract. In this paper, we propose a surgical thread model in order for surgeons to practice a suturing task. We first model the thread as a spline animated by continuous mechanics. The suture is simulated via socalled ”sliding point ” constraints, which allow the spline to move freely while constrained to pass through specific piercing points. The direction of the spline at these points can also be imposed. Moreover, to enhance realism, an adapted model of friction is proposed, which allows the thread to remain fixed at the piercing point or slides through it. Our model yields to good results showing realistic behavior, robust computation and interactive rates. 1

In this paper we describe an animation of a human platform diver. We simulated the motion of the diver using a dynamic model and a control system. The dynamic model is a 32 degree-of-freedom rigid body model with dynamic parameters similar to those reported in the literature for humans. The control system uses algorithms for balance, jumping, and twisting to initiate the dive, proportionalderivative servos to perform the aerial portion of the dive, and a state machine to sequence the actions throughout the dive. The motion of the simulated diver closely resembles video footage of dives performed by human athletes. The combination of dynamic simulation and a control system allowed us to animate the diver using high level commands. The control and simulation techniques presented in this paper may be useful for analysis of sports performance and for providing realistic motion for synthetic actors in computer animation and virtual environments. Keywords: Human Figure Animation, Simulatio...

This article presents a new method to achieve heterogeneous physical simulation, within the same global system, of both deformable and rigid-bodies objects, whatever their intrinsic nature. The proposed approach combines several mechanical formalism in the same system and offers a common constraint management via Lagrange multipliers. This allows the simulation of a wide variety of models, including deformable and rigid parts linked by constraints. Some applications of this approach are presented to show its effectiveness. keywords: Physically-based animation, Lagrange multipliers, Constraints, Rigid bodies, Deformable continuous models.

this document.

In this paper, we show a method to interact with physically-based environments in a way which guarantee their integrity whatever the mechanical properties of the virtual interaction tool and the control device. It consists in an extension of the god-object concept. The interaction tools are modeled as physical bodies which tend to reach, if possible, the position maintained by the user. Their behavior is computed via the dynamic laws of motion by the simulation engine, as the other bodies in the scene. The cases of articulated rigid bodies and deformable bodies are studied. This mechanism also provides a unified framework which allows the control of virtual objects via devices providing force feedback or not. Finally, some applications including virtual surgery are shown to illustrate the effectiveness of the approach.