In order to better understand perceptual and cognitive features of shapes and motions associations, we first create synthetic animation composed of realistic motions modeled by physical modeling mapped on abstract shapes. Second, we propose such paradoxical and surprising animations to subject's observations and we analyze them by qualitative analysis methods.

Session "Interactive art program track 3: visual"

For hand–object interaction in real situations the interplay between the local tactile interaction and force interaction seems to be very important. In current haptic interfaces, however, two different trends are present: force feedback devices which offer a permanent invariable grip and a resultant force, and tactile devices, which offer variable local patterns, often used for texture rendering. The purpose of the present work is to combine the two types of devices in a coherent manner. In the new device presented here, the tactile stimulation is obtained from strictly the same interaction loop, and obeys to the same physical model, as the force feedback, providing the information on the spatial distribution of forces circulating between the object and the fingertip. An experiment on following sharp edges of virtual object comparing the force feedback alone and different tactile augmentations is presented and discussed, alone with some open epistemological issues.

In this paper we explore, by means of three pilot observational studies using virtual objects, how direct perception through action of multi-sensory audio-visual and haptic object properties support the creation of new categories of believable and plausible objects than can be perceived as being different from those that were presented The three experiments are based on variations of "Pebble boxes" and consist in the exploration and the manipulation of multiple moving multi-sensory objects (the Pebbles). Results from observations and informal interviews with participants illustrate how an inferred scene is apparently constructed from experience, as assumed in the cognitive Enactive concept, by means of three complementary strategies: the Emergent Exploratory Procedures, Dynamic Manipulation Adaptation, and Adaptive Experimental Learning. Findings also illustrate the complementarities between the so-called ergotic and semiotic situations with respect to the strategies that were apparently successful in inferring a believable and plausible scene.Several fundamental questions arise which are relevant to the Enactive assumption with respect to the coupling between perceiving and acting, some of which are discussed here.

The work presented in this paper focuses on the description and evaluation of an augmented reality nanomanipulator, called "nanoLearner platform" used as educational tool in practical works of nanophysics. Through virtual reality associated to multisensory renderings, students are immersed in the nanoworld where they can interact in real time with a sample surface or an object, using their senses as hearing, seeing and touching. The role of each sensorial rendering in the understanding and control of the "approach-retract" interaction has been determined thanks to statistical studies obtained during practicals. Conjointly, qualitative analyses of student reports revealed the NanoLearner platform efficiency, compared to the use of classical tools. Finally, we present extension of the use of this innovative tool for investigating nano effects in living organisms and for allowing grand public to have access to a natural understanding of nanophenomena.

Abstract As quoting in the philosophy of free dance: ‘understanding the directions for a free dance performer stems mainly from the qualities and energy of the movement rather from spatial criteria,’ we advocate generating computing dance movement by dynamic and energy. In this paper, we present a set of dynamic models according to dance verbs: ‘to sway,’ ‘to squat down,’ ‘to develop,’ ‘to walk,’ ‘to turn,’ and ‘half turn step over step.’ For each of them, we designed the simplest physically based particle model. Among them, user has a high‐level motion control to modify the quality of such dynamically generated movement, for example, light, strong, sudden, sustained, etc. These dynamic models are hence well suited to produce spontaneous motion that looks natural and plausible. Furthermore, by designing dance movement only with the necessary minimal models, it is possible to produce complex dance movement that exhibits energetic consistency as underlain by the philosophy of free dance. Copyright © 2006 John Wiley & Sons, Ltd.

International audience

With the development of communication methods and devices, it became possible to perform actions more and more distant from the task spaces. These new tools raise today the question of Presence of distant spaces with a growing accuracy. In a first part, we show that the distance between the manipulation space and the task space, in a teleoperation activity, points to different meanings. However, the same need for a strong Presence of the task space raises, whatever the distance between these spaces is. We then discuss the notion of Presence as a cross-point between technological and scientific disciplines, and propose some general idea that may reinforce it. In a second part, we illustrate the previous ideas with the example of manipulation of nano-objects. We show how it is possible to enhance dramatically the feeling of Presence of the nano-objects to be perceived and manipulated, by adding haptic bi-directional transducers to the visual and acoustical sensors used today. By the end, we defend the idea that the feeling of Being there is deeply dependent on multisensoriality.

This paper shows how it is possible to extend a discrete physics modeling framework, the mass-springs systems used to describe objects in animation, to robotics applications. Previous work on mass-springs systems resulted in modeling physical phenomena or in artificial life animation synthesis. This paper analyses the possibility to control a physical system by another in order to model complex heterogeneous time-dependent systems, as found in robotics applications or in artificial life. The work described is based on Cordis-Anima, a particle-based modeling framework. An application of a mobile-following-target, in which both mobile and controller are complex mass-springs structures and all interaction forces with the environment are simulated, is presented. Several synthesis animation frames are presented showing the mobile and controller's behavior.

Physically-based particle models are used by an increasing community of computer graphics researchers and users in order to produce a large variety of dynamic motions. Among all of the methods dedicated to the coating of point models, the implicit surface method has proven to be one of the most powerful. However, for the visualization of a wide variety of objects ranging from smoke to solids, the time-independent coating of traditional implicit surfaces appears to be dynamically too poor and restrictive. We propose a generalization of classic implicit surfaces which are able to produce a larger variety of particle coatings, from rigid solids to highly deformable objects and even wave propagation and fluid flow coatings, thus handling all these disparate categories with the same paradigm. The method consists of extracting the coating from a field function which is not predetermined but calculated as the modulation of a dynamic discrete medium by particles. For these reasons, the coating behaviors present higher-order dynamic behaviors closely correlated with the dynamics of skeleton particles.

Soils in natural environments present complex dynamical behaviors: rolling stones, deformations, compressions, avalanches and collapses. The geometry of the terrain can be highly modified by the vehicle itself during its displacement; simultaneously, the behavior of the vehicle also becomes more complex. Deformable soils, such as loose soils cannot be modelled by solid physics and they require the use of accurate mass decomposition and mass-mass interactions. These are the basis of the model-simulator we used, called CORDIS-ANIMA, in which every kind of physical object is modelled by a set of precise masses in physical interaction. This paper illustrates the physically-based object simulations of various off-road vehicles moving on deformable soils, leaving tyre traces, spinning, skidding and even sinking.

The paper deals with the modeling of loose soil (sandy, muddy, etc.). When an object moves on such grounds, the object's and the soil's movement both depend on the mutual physical interactions, and therefore are very difficult to achieve with kinematic or geometric models. We use a particle based dynamic modeler and achieve a discrete model of plasticity, which accounts for the influence of the soil on objects moving on this soil, but also for the influence of the object on the movement and the shape of the soil. Thus we have simulated soil compression and piling, vehicles leaving tyre traces spinning, skidding and even sinking. This first step is the simulation of the soil object system at a discretization scale that can be termed "intermediate". A subsequent step consists of the simulation of a finer physical soil model in order to account for smaller scale dynamic phenomena.

The paper deals with physical modelling and more particularly with the particle based modelling technique used by the Cordis-Anima modeller simulator designed by the ACROE. Our goal is to show that is possible to model a rigid articulate system with a complex geometry thanks to this technique. We chose an example of this category that seemed to us to be the most significant (complex and complete) of this problem: a clockwork.

In the field of robotics, some vehicles work in natural sites. Such robots have to cope with a geometrically unstable environmental and thus have a complex dynamic behavior. Therefore we need a physical model of the robot-environment system and of a sufficiently realistic physical simulation. We present models of various types of motor vehicles and loose soils. Results of dynamic simulations of these vehicles are also presented.

In the field of robotics, some autonomous vehicles work in natural sites. One problem for the autonomous system is to plan a path to the goal. A usual method uses potential fields to find a global path. With this method, obstacles must be clearly defined. But this is not the case in such natural environments. A new physically based potential method is introduced to find paths such as, for instance, a winding path to a pass. Moreover, locally, vehicles have to cope with a geometrically unstable environment and thus have a complex dynamic behavior. Thus it is necessary to elaborate a physical model of the robot-environment system. Generally, the two plannings, global and local, are independent. The introduced potential method resorts to the simulations of the vehicles to find a feasible path.

This paper addresses the motion prediction problem of a planetary vehicle under the following hypotheses: the vehicle must be able to move on both, natural and hostile terrains, it must have the ability of selecting and applying several navigation strategies depending on the characteristics of the terrain, and it must be capable of showing complex behaviors derived by both, its sophisticated mechanical structure and the vehicle/terrain physical interactions. An original method to simulate the dynamic behavior of the vehicle (i.e., vehicle/terrain interactions, sliding or gripping effects...) when executing motions having the previous characteristics is presented. This method is based on the concept of physical modeling which has been initially developed in the field of computer graphics and man/machine communication. The basic idea is to consider that motions and/or deformations of physical objects result from the application of physical laws involving a set of forces whose application points depend on the intrinsic structure of the interacting objects.

Abstract Programming the motions of an autonomous planetary robot moving in an hostile and hazardous environment is a complex task which requires both the construction of nominal motion plans and the anticipation as far as possible of the effects of the interactions existing between the vehicle and the terrain. In this paper we show how physical models and dynamic simulation tools can be used for amending and completing a nominal motion plan provided by a classical geometrical path planner. The purpose of our physical modeller‐simulator is to anticipate the dynamic behaviour of the vehicle while executing the nominal motion plan. Then the obtained simulation results can be used to assess and optimize the nominal motion plan. In the first part, we outline the physical models that have been used for modelling the different types of vehicle, of terrain and of vehicle‐surface interactions. Then we formulate the motion planning problem through the definition of two basic abstract constructions derived from physical model: the concept of generalized obstacle and the concept of physical target. We show with various examples how it is possible, when using this method, to solve the locomotion problem and the obstacle avoidance problem simultaneously and, furthermore, to provide the human operator with a true force feedback gestural control over the simulated robot.

International audience

Physical modeling for animation is now firmly established. The present aim is to design and build a structured and well-defined tool rather than merely specific algorithms to simulate physical knowledge. We will first define the basic functions of a modeler - simulator for physical modeling which enables operator gestural control, and where the simulation processes are real time oriented. These constraints cannot be achieved by any kind of models and algorithms. Concerning the theoretical elements, the choice of the underlying Physics and the categorization of interactions will be presented. We will then introduce the Cordis-Anima system, its constructive langage, its real time simulator and its force feedback gestural transducers. Finally, we will describe, with some examples, how we model, simulate and manipulate a large variety of physical objects and scenes with our system.

Deals with the problem of planning the motions of a complex land vehicle moving in a natural environment. The contribution presented is a motion generator which predicts the dynamic behaviour of the vehicle when executing a given nominal motion plan. This plan is expressed in terms of a channel to follow and of a set of intermediate subgoals to reach. Solving this motion generation problem requires to explicitly reason about the geometric and the physical aspects of the movements that the vehicle has to execute. In the authors' approach, this is done using two basic constructions derived from the concept of physical model: the 'generalized obstacles' are used for physically guiding the movements of the vehicle using an explicit model of the vehicle/terrain interactions, and the 'physical targets' are used to map the strategic information onto the physical representation of the world.>