ERCIM News No.20 - January 1995

Fifth Eurographics Workshop on Animation and Simulation

by Gérard Hégron

The Fifth Eurographics Workshop on Animation and Simulation, was held in Oslo on the 17-18 September 1994. The event was organized by SINTEF and the Eurographics Working Group 4 and supported by the Ercim and Eurographics organisations.

The purpose of this workshop was to encourage the exchange of experience and knowledge between the animation and simulation communities on the general themes of : modelling, animation, motion control, and simulation. The workshop was attended by around 37 participants.

The event was co-chaired by Gérard Hégron (Ecole des Mines de Nantes, France) and Olov Fahlander (Linkoping University, Sweden) and local organization was undertaken by Morten Daelhen (SINTEF, Norway). The Program Committee invited Demetri Terzopoulos from the University of Toronto to speak on the links between motion synthesis and motion analysis. The main topics covered by the papers were the animation and the metamorphosis of deformable objects; the motion control of multi-body systems and the simulation of physical phenomena.

Five paper sessions were organized:

Shape transformation and applications

A new technique for computing continuous transformations between star-shaped polyhedral objects was presented. The paper described how to smoothly fuse two moving polyhedra whilst preserving the volume of the sum of the components using a radial projection technique. Philippe Limantour from Medialab, France, described a new approach to facial animation involving the real-time mapping of parameters ininterpolating canonical expressions along a unit vector basis.

Demetri Terzopoulos talked about the synthesis and analysis of motion illustrated using the research conducted by the Visual Modelling group at the University of Toronto. Here, a unified theoretical and computational framework for computer graphics and vision is being developed. The approach is a physics-based. A fundamental goal of this research is to create ever more powerful techniques for the synthesis and analysis of motion.

Animation of deformable objects

Two papers described the use of implicit surfaces to embed physical models in order to deal with deformation. The first paper, dealing with character animation, attempted to incorporate within the implicit surface technique traditional animation principles, such as squash and stretch, follow through and exaggeration.

In the second paper, Jason Harrison and David Forsey (INRIA) formulate a geometric approach for controlling a collision response kinematically by moving points on a multi-resolution representation of the object surface toward goal points. The elastic material is defined by an implicit formulation over a discrete inelastic layer and this is well suited for automatic collision and response.

Motion control

Stéphane Donikian from INRIA presented a real-time, hierarchical and multi-agent system which integrates the different approaches to behavioural animation. A real-time driving simulation example, was used to validate his concepts.

In the same way, Joseph Kearney from the University of Wisconsin and Iowa presented his system for controlling the behaviour of complex mechanisms in simulation. It is based on hierarchies of communication and concurrent asynchronous state machines.

The four remaining papers were devoted to the motion control of articulated figures.

Physical phenomenon and visualisation

C.H. Perry from the MIT Media Laboratory, USA proposed a technique for fire synthesis which combines a flame model with a fire-speading model. There are parameters for explicitly controlling wind, gravity and the flammability of the material being burned.

Miguel Aguas from IST, Portugal, presented a method for visualising hierarchical environments at interactive frame rates. The technology is based on a predictive physical algorithm within the polygon structure of the model.

Partical systems

During this last session ACROE presented some results based on their particle-based modelling technique. Their first paper developed the modelling, simulation and the visualization of granular materials in order to produce such complex phenomena. Examples include the construction of a pile from independent particles, avalanches and the phenomenon of internal collapse. Their second paper described an application of their approach to the simulation of a clockwork mechanism, which reproduces the measure of time and the sequencing of events. A presentation of a parallel implementation of a dynamic system of particles closed the session.

Future plans

The 6th Eurographics Workshop on Animation and Simulation is scheduled to take place around August/September `95 in Maastricht, The Netherlands. The special theme is the simulation and animation of autonomous and living systems. The aim is to illustrate the valuable synergy of animation and artificial life.

Please contact:
Gérard Hégron - Ecole des Mines de Nantes
Tel: +33 51 85 81 60