A 3D Data Intensive Tele-immersive Grid

International audienceNetworked virtual environments like Second Life enable distant people to meet for leisure as well as work. But users are represented through avatars controlled by keyboards and mouses, leading to a low sense of presence especially regarding body language. Multi-camera real-time 3D modeling offers a way to ensure a significantly higher sense of presence. But producing quality geometries, well textured, and to enable distant user tele-presence in non trivial virtual environments is still a challenge today. In this paper we present a tele-immersive system based on multi-camera 3D modeling. Users from distant sites are immersed in a rich virtual environment served by a parallel terrain rendering engine. Distant users, present through their 3D model, can perform some local interactions while having a strong visual presence. We experimented our system between three large cities a few hundreds kilometers apart from each other. This work demonstrate the feasibility of a rich 3D multimedia environment ensuring users a strong sense of presence

A Hierarchical Component Model for Large Parallel Interactive Applications

Extended version of NPC 2007 article.International audienceThis paper focuses on parallel interactive applications ranging from scientific visualization, to virtual reality or computational steering. Interactivity makes them particular on three main aspects: they are endlessly iterative, use advanced I/O devices, and must perform under strong performance constraints (latency, refresh rate). A data flow graph is a common approach to describe such applications. Edges represent data streams while vertices are nodes processing incoming data streams and producing new data streams. When applications become large, this approach shows its limits in terms of maintainability and portability. In this paper, we propose to use the composite design pattern to extend this model for supporting hierarchies of components. The component hierarchy is traversed to instantiate the application and extract the data flow graph required for the execution. This approach has been implemented for the FlowVR middleware. It enables to define parametric composite components, commonly called skeletons, that can be reused in various applications. This approach proved to significantly leverage application modularity as presented in different case studies