EUROGRAPHICS Workshop IPT & EGVE Workshop (2005) Colosseum3D – Authoring framework for Virtual Environments Anders Backman VRlab/HPC2N, Umeå University, Sweden Abstract This paper describes an authoring environment for real time 3D environments, Colosseum3D. The framework makes it possible to easily create rich virtual environments with rigid-body dynamics, 3D rendering using OpenGL Shaders, 3D sound and human avatars. The creative process of building com- plex simulators is supported by allowing several authoring paths such as a low level C++ API, an ex- pressive high level file format and a scripting layer. To exemplify the use of the framework, an immersive wheelchair simulator application is presented. A natural and intuitive interaction method is implemented using dynamic simulation. Categories and Subject Descriptors: I.3.4 [Graphics Utilities]: Software support - I.3.6 [Methodology and Techniques]: Interaction techniques 1. Introduction Authoring a rich multimodal real time 3D environment can be a daunting task. Virtual Reality (VR) is a cate- gory of 3D graphics applications, where the user is immersed into the virtual works using display systems such as head mounted displays (HMD), CAVE [CSD93] or other projection systems. A 3D simulator must perform many complex tasks, such as parsing 3D geometry and drawing it efficiently, simulating dynamic objects, handling collision detection, reading sound files and playing them accordingly to the simulation, handling of system events etc. This work concentrates on the authoring process of virtual environments with both physical as well as vis- ual content. The framework described, Colosseum3D, is a modular system for building large scale simulation environments, based on existing open source software. To exemplify the use of the framework, a simulator developed for the department of Community Medicine and Rehabilitation, a wheelchair simulator will be pre- sented. As a result of that simulator an intuitive close up interaction method using dynamics simulation has been developed. The framework can be described with the initial gen- eral goals of the project. We needed a framework that: • supported a creative process in terms of prototyp- ing • could simulate a rich dynamic environment • could support an intuitive and natural interaction method By defining a general extendable file format, rich scripting capability and exporters from commonly used 3D modeling software we can aid the creative process of building dynamic simulations. The details of the interaction between objects are handled by the simulation. Also, by using dynamic simulation, the interaction between the immersed user and nearby objects can be made to mimic the way we interact in daily life. Dynamic behavior in a VE can be created using • Scripts – triggered by user inputs or collision de- tection • Controllers – continuous response of the users input • Simulation – e.g. dynamics In practice, a simulation environment is built up us- ing all of the above methods. A vast majority of the Virtual Environments (VEs) built in the past have been based on static graphics and at most animations triggered by user action. Explicitly