Case study: full-size virtual models of trains Francisco J. Serón Diego Gutiérrez Juan A. Magallón seron@posta.unizar.es diegog@phoebe.cps.unizar.es magallon@posta.unizar.es Emilio J. Sobreviela José A. Gutiérrez emilio@ivo.cps.unizar.es spd@daphne.cps.unizar.es Grupo de Informática Gráfica Avanzada Informática e Ingeniería de Sistemas, Centro Politécnico Superior Universidad de Zaragoza C/ María de Luna, 3, 50015 Zaragoza http://giga.cps.unizar.es Abstract Simulation of models, in all different areas, is an expanding, attractive line of work. More and more applications are taking advantage of the improving technology and knowledge in this field, achieving results that would have been impossible to achieve with a real model, or foreseeing facts that would have been encountered too late in the production process otherwise. The train industry is one possible beneficiary of this approach. Usually, before commencing the fabrication process of a new train, the construction of a full-size model is mandatory. Instead of building this full-size real model, which leaves little room for later, last-minute modifications, a virtual model could be built in the digital realm, thus offering a new platform for easier interaction with it. In this article, a simulation of a train is presented for visual, aesthetics and ergonomic issues. The simulation runs on a PC-based CAVE-like architecture, and combines static and dynamic computer generated imagery, both with and without stereoscopy for 3D visualization, as well as Augmented Virtuality techniques for the integration of the train with its environment. Key words Simulator, CAVE, industrial design, stereoscopy, virtual prototyping 1. INTRODUCTION Simulation is a way of working that allows the study of a physical system by substituting it for another, more suitable to observation or measure. Different interests can be addressed by means of simulation. These different approaches require different layers of complexity in the simulation: an astronaut trainer, for instance, will most likely need to be able to simulate, up to a certain degree, the dynamics of the system. On the other hand, a car company might not need such realism if only the visual appearance is to be discussed by means of the simulation. But, once the general shape is approved, it might then need to undergo a simulated wind tunnel test, which will require a new layer of complexity in the simulation. Thus, motivation guides the simulation itself. Several simulations will work better by using Virtual Reality techniques [Hollands96] [Burdea96] [Kalawsky93]. These techniques create immersive environments that make the interaction between man and simulator as indistinguishable from reality as possible. Most of the times this implies the concept of real time, although as we have seen its necessity will be driven by the goal of the simulation. The fields where simulators are most often used are military, civil and leisure [Dodsworth98]. Several internet addresses offer information about some of the best simulators nowadays, and can be found at [INRETS] [DAIMLER]. 1.1 Virtual Prototyping