Abstract not found

Diamond Park is a social virtual reality system in which multiple geographically separated users can speak to each other and participate in joint activities. The central theme of the park is cycling. Human visitors to the park are represented by 3D animated avatars and can explore a square mile of 3D terrain. In addition to human visitors, the park hosts a number of computer simulations including tour buses and autonomous animated figures. Diamond Park is

Distributed, real-time multiplayer computer games (MCGs) are in the vanguard of utilizing the networking possibilities. Although related research have been done in military simulations, virtual reality systems, and computer supported cooperative working, the suggested solutions diverge from the problems posed by MCGs. With this in mind, this paper provides a concise overview of four aspects affecting networking in MCGs. Firstly, networking resources (bandwidth, latency, and computational power) set the technical boundaries within which the MCG must operate. Secondly, distribution concepts encompass communication architectures (peer-to-peer, client/server, server-network), and both data and control architectures (centralized, distributed, replicated). Thirdly, scalability allows the MCG to adapt to the resource changes by parametrization. Finally, security aims at fighting back against cheating and vandalism, which are common in online gaming. Keywords---Computer games, networking, online entertainment, distributed interactive simulation, virtual environments.

Networking forms an essential part of multiplayer computer games. In this paper, we review the techniques developed for improving networking in distributed interactive real-time applications. We present a survey of the relevant literature concentrating on the research done on military simulations, networked virtual environments, and multiplayer computer games. We also discuss on resource management, consistency and responsiveness, and networking on the application level.

Temporal links allow recordings of multi-user sessions to be dynamically inserted into current virtual worlds in a flexible and principled way. This paper explores key applications of temporal links, showing how they can add new content to virtual worlds, support usability and system evaluation, and link VR to other media such as film and television. These applications illustrate just some of the possibilities of a ubiquitous and flexible record and replay facility such as temporal links. Building on our experience of implementing temporal links in the MASSIVE-3 system, we identify key requirements for system architectures that wish to support an equivalent mechanism.

Augmented Reality (AR) provides a natural interface to the "calm" pervasive technology anticipated in large-scale Ubiquitous Computing environments. However, the range of classic AR applications has been limited by the scope, range and cost of sensors used for tracking. Hybrid tracking approaches can go some way to extending this range. We propose an approach, called Ubiquitous Tracking, in which data from widespread and diverse heterogeneous tracking sensors is automatically and dynamically fused, and then transparently provided to applications. A formal model represents spatial relationships between objects as a graph attributed with quality-of-service parameters. This paper presents a software implementation, in which a dynamic data flow network of distributed software components is thereby constructed in response to queries and optimisation criteria specified by applications. This implementation is demonstrated using a small laboratory example, and larger setups modelled in a simulation environment.

Large, complex 3D scenes are best rendered in an output-sensitive way, i.e., in time largely independent of the entire scene model's complexity. Occlusion culling is one of the key techniques for output-sensitive rendering. We generalize existing occlusion culling algorithms, intended for static scenes, to handle dynamic scenes having numerous moving objects. The data structure used by an occlusion culling method is updated to reflect the objects' possible positions. To avoid updating the structure for every dynamic object at each frame, a temporal bounding volume (TBV) is created for each occluded dynamic object, using some known constraints on the object's motion. The TBV is inserted into the structure instead of the object. Subsequently, the object is ignored as long as the TBV is occluded and guaranteed to contain the object. The generalized algorithms' rendering time is linearly affected only by the scene's visible parts, not by hidden parts or by occluded dynamic objects. Our tec...

In this paper we present DeepMatrix, a virtual environment system based on two open technologies, Java and the Virtual Reality Modeling Language (VRML). The system is designed for use on current consumer hardware and requires only a standard Web browser with VRML plug-in. Due to a lean client – server implementation, system performance is superior to comparable approaches and easily extensible. This paper also introduces authoring for Deep-Matrix environments and discusses results drawn from a large experimental implementation of widely varying and interconnected virtual worlds.

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Interest management aims to overcome limited network resources to provide a distributed virtual environment (DVE) that is scalable in terms of number of users and virtual world complexity (number of objects). Interest management limits interactions between objects in a virtual world by only allowing objects to communicate their actions to other objects that fall within their influence. An important aspect of any interest management scheme is the ability to identify when objects should be interacting and enable such interaction via message passing. Existing approaches to interest management are not suited to objects that may travel at greatly varying speeds and may only interact briefly. In such a scenario, the time taken by existing interest management schemes to resolve which objects influence each other may be too large to enable the desired interaction to occur. In this paper we present an approach to interest management based on the predicted movement of objects. Our approach determines the frequency of message exchange between objects on the likelihood that such objects will influence each other in the near future. Via this mechanism we aim to ensure a scalable DVE that may satisfy message exchange requirements of briefly interacting objects irrelevant of the speed such objects may traverse a virtual world.