MELIES: Modelling equipment for live electronic streaming

• Research unit: EU RFP
• Project number: 01.0002-1

Key words (English)

Dynamics computation; real-time animation; cloth animation; cloth wrinkling simulation;
Information; Media; Information Processing; Information Systems; Social Aspects

Alternative project number (English)

EU project number: IST-2000-28700

Research programs (English)

EU-programme: 5. Frame Research Programme - 1.2.3 Multimedia content and tools

Short description (English)

See abstract

Partners and International Organizations (English)

The University of Surrey (UK), Ecole Polytechnique Fédérale de Lausanne (CH), Giunti Multimedia srl (I), Ernst Klett AG (D), University of Geneva (CH), XD Productions (F)

Abstract (English)

The goal of MELIES is to provide new technologies for the creation of photo-realistic clothed human characters from video sequences. MELIES explores an innovative way to capture and synthesize motion using the power of computer graphics and computer vision based techniques. The 3-D models will contain all the information required to animate them within a virtual environment.
MIRALab is responsible for the generation of realistic simulation and visualization of clothes on actors in real-time. The two main tasks that were addressed during this first period are:
1. the development of a hybrid clothes simulation model that combines geometric deformations and a simplified mechanical simulation algorithm that animates the flying fabric regions realistically
2. the investigation for developing a wrinkling algorithm for fabrics to enhance the realistic appearance of the clothes simulation

1) The main features of the proposed hybrid approach for clothes simulation are to:
· Exploit the merits of both the physical-based and geometric deformations.
· Exploit predetermined conditions between the cloth and the body model.
· Avoid complex collision detection and physical deformations wherever it is possible.

In this approach the garments are segmented into three layers based on their distance from the body. This segmentation is performed automatically, and each of the layers is animated according to a different animation scheme. For layer 1 'Stretch Clothes' (garments that stick to the body with a constant offset) geometric deformation techniques are employed to keep a constant distance between the cloth and the underlying skin surface. For layer 2 'Loose Cloth' (garments that move within a certain distance of the skin surface), limbs are approximated with cylinders and the cloth vertices are constrainted to move inside spheres that are attached to the skin, whereas for the trunk, a simplified mesh that approximates the garment is animated dynamically. The nodes of this mesh are then used as control points to apply Free-Form Deformation to the whole garment mesh. For layer 3 'Floating Cloth' (garments that flow around the body) a mass-spring system with the classic Euler Integration method and a simplified collision detection with legs that are approximated by cylinders are applied.
The algorithm based on this approach is described in the paper 'Real-time Animation of Dressed Virtual Humans' by Cordier and Nadia Magnenat-Thalmann, presented at the EUROGRAPHICS 2002 conference.

2) The dynamics wrinkling algorithm for fabrics is aimed at enhancing the realistic appearance of the dynamics simulation without penalizing the computation performance. This is necessary as a dense mesh that can create sufficient realistic appearance results in a heavy computational burden. Therefore, a method for using a coarse and dense mesh is being investigated. The dynamics of the coarse mesh is simulated using a physics based accurate method that accounts for both external and internal forces in the cloth. The dynamics of the dense mesh makes use of a simpler approach of simulation that accounts only for the internal forces. Currently work is in progress for integrating this approach into the simulation of the dynamics of clothes.

References in databases (English)

Swiss Database: Euro-DB of the
State Secretariat for Education and Research
Hallwylstrasse 4
CH-3003 Berne, Switzerland
Tel. [phone]
Swiss Project-Number: 01.0002-1