This paper presents the architecture of the VHD++ real-time development framework that after several years of intensive research, design, and development effort has been released and enters its validation phase. This paper discusses the key aspects involved in architectural structure, design and practical implementation of an efficient, flexible and extendible real-time software framework based on the modern 3D gameengine design principles. This framework supports researchers and application developers with rapid, component based development of VR/AR systems featuring advanced virtual character simulation technologies. The discussion covers motivation, main concepts, survey of related work, the main functional and design requirements, design principles and key architectural elements. It concludes with the initial validation results including overview of existing VHD++ based VR/AR virtual character simulation applications.

The Distributed Interactive Virtual Environment (DIVE) system is a mature toolkit that has been used for prototyping many collaborative virtual environment (CVE) applications [3]. Until recently, support for immersive systems has been limited to custom support for specific installations and the emphasis has been on broad support for desktop interfaces. Recently we have ported DIVE to the CAVElib ™ environment † and this paper describes application programming support for immersive users and our experience in using wide-area distributed applications involving immersive projection technologies. The resulting toolkit provides a very flexible system with which to build distributed VE applications involving a variety of platforms and interfaces.

The Syzygy software library consists of tools for programming VR applications on PC clusters. Since the PC cluster environment presents application development constraints, it is impossible to simultaneously optimize for efficiency, flexibility, and portability between the single-computer and cluster cases. Consequently Syzygy includes two application frameworks: a distributed scene graph framework for rendering a single application’s graphics database on multiple rendering clients, and a master/slave framework for applications with multiple synchronized instances. Syzygy includes a simple distributed OS and supports networked input devices, sound renderers, and graphics renderers, all built on a robust networking layer. 1.

Traditional ways to handle user input in software are uncomfortable when an application wishes to use novel input devices. This is especially the case in gesture based user interfaces. In this paper we describe these problems and as a solution we present an architecture and an implementation of a user input toolkit. We show that the higher level processing of user input such as gesture recognition requires a whole new kind of paradigm. The system we designed and implemented - FLexible User Input Design (FLUID) - is a lightweight library that can be used in different kinds of software. The potential application areas include all system where novel input devices are in use: virtual reality, entertainment systems and embedded systems.

We present an investigation of selection strategies designed specifically for the spatially immersive display (SID), CAVE TM-like situation. We address two common contexts of use of SID displays: single user head tracked, and two person with one non-head tracked demonstrator and a visitor. This second context is, in our experience, a common use scenario of SIDs, but it, and other issues specific to SIDs, are largely ignored in the literature, which has concentrated on head-mounted displays. We introduce a novel interaction technique, Shadow Cone Selection, which was designed for the situation of non-head tracked interaction. Through analysis and experiment, we show that it might be preferred over standard cone and ray-based selection techniques for some applications.

This paper describes VR Juggler, an Open Source platform used to develop and run virtual reality applications. We emphasize VR Juggler's ability to provide a uniform VR application environment and to allow extendibility to new devices without affecting existing applications. These features enable VR applications to evolve along side other technologies with minimal or no new developmental efforts.

Net Juggler, an open source library developed at LIFO, turns a commodity component cluster running the VR Juggler platform on each node into a single VR Juggler image cluster. Net Juggler parallelizes rendering computations for immersive projection environments but pre-rendering computations are redundant. In this paper, we present how a classical parallelization of the pre-rendering computations can be deployed and controlled with Net Juggler. This approach is demonstrated with an interactive fluid flow simulation. 1

In this paper we describe an infrastructure and prototype system for sharing of visiting experiences across multiple media. The prototype supports synchronous co-visiting by physical and digital visitors, with digital access via either the World Wide Web or 3-dimensional graphics.

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In the late 90’s, the emergence of high-performance 3D commodity graphics cards paved the way to the use of PC clusters for high-performance Virtual Reality (VR) applications. Today PC clusters are broadly used to drive multi-projector immersive environments, among other high-performance VR tasks such as tracking and sound synthesis. This survey presents the different approaches that have been developed to use PC clusters for VR applications. We review taxonomies and the most common software and hardware tools that enable us to take advantage of clusters. We also discuss some new trends for the near future.