Modeling Very Complex Geometric Assemblies: The Use of Discrete and Hierarchical Models

Abstract

Virtual Reality (VR) Systems allow immersive inspection of very complex environments, with direct interaction with the objects in the virtual scene. Low cost and affordable VR systems are becoming essential in application areas like Industrial Design, Medical Applications and Cultural Heritage and require sophisticated techniques for model inspection and interaction. Discrete geometric models can be very useful for some involved geometry processing algorithms like model repair, occlusion culling and multi-resolution and level of detail. The interest of these techniques and their potential in present and future VR applications will be discussed. This paper addresses the interest of discrete geometric models in volume-based geometric simplification, the use of discrete tiles for impostorbased extreme simplification, topology-preserving model repair techniques based on discrete membranes and specific algorithms for recovering polygonal shapes from discrete volume models. The use of out-of-core octrees for interactive navigation in very complex geometric assemblies is also presented and discussed.