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Collision Detection and Analysis in a Physically Based Simulation
 In Eurographics Workshop on Animation and Simulation
, 1991
"... We consider the geometric support in detecting and analyzing collisions and contact between arbitrarily shaped polyhedral objects for a physically based simulation. The contact detection is formulated as a static collisiondetection problem in threedimensional space. We address both robustness and ..."
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Cited by 28 (1 self)
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We consider the geometric support in detecting and analyzing collisions and contact between arbitrarily shaped polyhedral objects for a physically based simulation. The contact detection is formulated as a static collisiondetection problem in threedimensional space. We address both robustness and efficiency of the problem, and show how both can be achieved by using the brepindex data structure. 1 Introduction A computer simulation of physical systems that is based on rigidbody dynamics and that involves objects with arbitrary shapes requires the services of a geometric modeling system. The geometric modeling system is used initially to establish mass properties and to formulate constraints for the system's dynamics. When simulating the motion of objects in the presence of obstacles with possible collisions and prolonged contact, the geometric modeling system is used throughout the simulation. The dynamics modeler must inquire at each time step whether two bodies are about to colli...
A Unified Model for Physically based Animation and Simulation
 In Applied Modelling, Simulation and Optimization
, 1995
"... This paper presents the design of an expandable animation system in which rigid and deformable multibody systems are animated from the highlevel model of physical objects. This new model called dream (Deformable and Rigid objects Efficient for Animation Modelling) makes the simulation of rigid and ..."
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Cited by 4 (2 self)
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This paper presents the design of an expandable animation system in which rigid and deformable multibody systems are animated from the highlevel model of physical objects. This new model called dream (Deformable and Rigid objects Efficient for Animation Modelling) makes the simulation of rigid and deformable interconnected objects easy to design and to implement. dream is based on a unified abstracted model described by an entity relationship formalism. Traditionnal physically based models such as rigid solids and deformable objects (described by finite elements or by punctual massspring meshes) come from this common formalism. That is why our system integrates and unifies the physical models used in computer animation. Then the motion equations are automatically computed in a symbolic form by applying the principle of virtual works and Lagrange's equations. Theoretical, numerical and practical aspects of the model implementation and some experimental results are presented. Finally, ...
A Language For Multibody Systems Modelling And Simulation
 In 7 th European Simulation Symposium ESS, Nurembreg
"... This paper presents the design of an expandable simulation language in which rigid and deformable multibody systems are simulated from our abstacted model of physical objects. This new model called dream (Deformable and Rigid objects Efficient for simulAtion Modelling) makes the simulation of rigid ..."
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Cited by 1 (0 self)
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This paper presents the design of an expandable simulation language in which rigid and deformable multibody systems are simulated from our abstacted model of physical objects. This new model called dream (Deformable and Rigid objects Efficient for simulAtion Modelling) makes the simulation of rigid and deformable interconnected objects easy to design and to implement. dream model consists in a unified abstracted model based on an entity relationship formalism. Traditionnal physically based models such as rigid solids and deformable objects (described by finite elements or by punctual massspring meshes) come from this common formalism. That is why our system integrates and unifies the physical models used in mutibody systems simulation. Then the motion equations are automatically computed in a symbolic form by applying the principle of virtual works and Lagrange's equations. Theoretical, numerical and practical aspects of the model implementation and we present some experimental result...
Why should we Build Artificial Worms and How?
, 1992
"... In this paper it is argued that a certain class of intelligent systems is worth being investigated and developed. This class consists of elastic robots composed of many components having relativelysimple sensorymotor capabilities, whose most prominent biological realizations are worms, molluscs, e ..."
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In this paper it is argued that a certain class of intelligent systems is worth being investigated and developed. This class consists of elastic robots composed of many components having relativelysimple sensorymotor capabilities, whose most prominent biological realizations are worms, molluscs, elephant trunks and tongues. Understanding how such mechanisms are controlled is an important stage (not to say, a prerequisite) toward the development of "truelyintelligent" autonomous agents. As a preliminary step in this direction I describe a simple elastic object considered as a first approximation of an artificial worm and discuss its control principles.
Lecture Notes in Computer Science 1 Models with Biological Relevance to Control Anthropomorphic Limbs: A Survey
"... Abstract. This paper is a review of different approaches and models underlying the voluntary control of human handarm movement. These models, dedicated to artificial movement simulation with application to motor control, robotics and computer animation, are categorized along at least three axis: Di ..."
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Abstract. This paper is a review of different approaches and models underlying the voluntary control of human handarm movement. These models, dedicated to artificial movement simulation with application to motor control, robotics and computer animation, are categorized along at least three axis: Direct vs. Inverse models, Dynamics vs. Kinematics models, Global vs. Local models. We focus on sensorymotor models which have a biologically relevant control scheme for handarm reaching movements. Different methods are proposed with various points of view, related to kinematics, dynamics, theory of control, optimization or learning theory. 1
The Generation of Animated Sequences from State Transition Systems
"... We address the issue of the construction of a computer animation system by composing together a collection of behaviours for the individual objects which are to be animated. The behaviours are developed using a formal notation for state transition systems. The notation is particularly flexible, allo ..."
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We address the issue of the construction of a computer animation system by composing together a collection of behaviours for the individual objects which are to be animated. The behaviours are developed using a formal notation for state transition systems. The notation is particularly flexible, allowing both a constructive and constraining aproach to behaviour representation. The behaviour necessary for animating Newton's Cradle for an arbitrary number of spheres is developed as an example of the method. 2 Introduction The use of computers to assist in the production of animation sequences is well established. From simply being used to generate `inbetweened' 2d images for keyframed systems, to running complex simulations of particle systems, computers are used in every kind of animation today. Their use is, however, driven by the end result. The underlying method used for the animation is generally ignored in favour of assessing the aesthetic quality or the perceived `realism' of ...
Quick Tuning of a Reference Locomotion Gait
"... This paper presents a comprehensive system for adaptive replay of a computer animation sequence featuring the locomotion of a synthetic animal. The kinematic locomotion gait, which is supposed to be mostly stationnary, is tuned before being injected on the dynamic model of the animated animal. The ..."
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This paper presents a comprehensive system for adaptive replay of a computer animation sequence featuring the locomotion of a synthetic animal. The kinematic locomotion gait, which is supposed to be mostly stationnary, is tuned before being injected on the dynamic model of the animated animal. The animator can take benefit from this new flexibility in order to fulfill some goals, like steering the animal towards a target. The reference gait kinematic trajectories are expanded on a wavelet redundant basis, and tuned through varying the wavelet parameters. Because the optimization process is timeconsuming, we propose to carryout all optimizations beforehand and send the outcomes in a training set for a neural network, whose role is to compress data and to interpolate in between the training samples. At runtime, the network emulates the behaviour of the optimization process and automatically tailors the gait parameters. This approach paves the way towards the definition of a readytou...
Simulation Dynamique et Applications Robotiques
, 1996
"... We describe models and algorithms designed to produce efficient and physically consistent dynamic simulations. These models and algorithms have been implemented within the Robot\Phi system[55] which can potentially be configured for a large variety of interventionstyle tasks such as dextrous manip ..."
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We describe models and algorithms designed to produce efficient and physically consistent dynamic simulations. These models and algorithms have been implemented within the Robot\Phi system[55] which can potentially be configured for a large variety of interventionstyle tasks such as dextrous manipulations with a robot hand; manipulation of nonrigid objects; teleprogramming of the motions of an allterrain vehicle; and some robot assisted surgery tasks (e.g. positioning of an artificial ligament in knee surgery). The approach uses a novel physically based modeling technique to produce dynamic simulations which are both efficient and consistent according to the laws of the Physics. The main advances over previous works in Robotics and Computer Graphics fields are twofold: the development of a unique framework for simultaneously processing motions, deformations, and physical interactions; and the incorporation of appropriate models and algorithms for obtaining efficient processing ti...
Internal Models for Motion Control
, 2001
"... This paper is a review of different approaches and models underlying the voluntary control of human handarm movement. These models, dedicated to artificial movement simulation with application to motor control, robotics and computer animation, are categorized along at least three axis: Direct vs ..."
Abstract
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This paper is a review of different approaches and models underlying the voluntary control of human handarm movement. These models, dedicated to artificial movement simulation with application to motor control, robotics and computer animation, are categorized along at least three axis: Direct vs. Inverse models, Dynamics vs. Kinematics models, Global vs. Local models. We focus on sensorymotor models which have a biologically relevant control scheme for handarm reaching movements. Different methods are proposed with various points of view, related to kinematics, dynamics, theory of control, optimization or learning theory.