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Now showing 1 - 6 of 6
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    Building Expression into Virtual Characters
    (The Eurographics Association, 2006) Vinayagamoorthy, V.; Gillies, M.; Steed, A.; Tanguy, E.; Pan, X.; Loscos, C.; Slater, M.; Brian Wyvill and Alexander Wilkie
    Virtual characters are an important part of many 3D graphical simulations. In entertainment or training applications, virtual characters might be one of the main mechanisms for creating and developing content and scenarios. In such applications the user may need to interact with a number of different characters that need to invoke specific responses in the user, so that the user interprets the scenario in the way that the designer intended. Whilst representations of virtual characters have come a long way in recent years, interactive virtual characters tend to be a bit "wooden" with respect to their perceived behaviour. In this STAR we give an overview of work on expressive virtual characters. In particular, we assume that a virtual character representation is already available, and we describe a variety of models and methods that are used to give the characters more "depth" so that they are less wooden and more plausible. We cover models of individual characters emotion and personality, models of interpersonal behaviour and methods for generating expression.
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    Collaboration in Tele-Immersive Environments
    (The Eurographics Association, 2002) Mortensen, J.; Vinayagamoorthy, V.; Slater, M.; Steed, A.; S. Mueller and W. Stuerzlinger
    This paper describes a study of remote collaboration between people in a shared virtual environment. Seventeen subjects were recruited at University College London, who worked with a confederate at University of North Carolina Chapel Hill. Each pair was required to negotiate the task of handling an object together, and moving a few metres into a building. The DIVE system was used throughout, and the network support was Internet-2. This was an observational study to examine the extent to which such collaboration was possible, to explore the limitations of DIVE within this context, and to examine the relationship between several variables such as co-presence and task performance. The results suggest that although the task is possible under this framework, it could only be achieved by various software tricks within the DIVE framework. A new Virtual Environment system is required that has better knowledge of network performance, and that supports shared object manipulation across a network. The participant-study suggests that co-presence, the sense of being together with another person, was significantly and positively correlated with task performance
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    Interactive Shape Control of Interpolating B-splines
    (Blackwell Science Ltd and the Eurographics Association, 1992) Krokos, M. A.; Slater, M.
    This paper presents a new methodfor providing interactive shape control of interpolating B-splines. The CAD designer can directly interact with geometric entities defined on the B-spline at any interpolated data point- shape adjustments can be performed either globally or locally. Our approach is based on B?-splines of order k (?,k ?1), i.e. ?-reparametrized, classical B-splines. The method presented can be easily generalised to surfaces defined either as tensor products or by using the skinning technique- interactive shape control can be provided in both surface parametric directions.
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    An Innovative Design Approach to Build Virtual Environment Systems
    (The Eurographics Association, 2003) Oliveira, M.; Crowcroft, J.; Slater, M.; Andreas Kunz and Joachim Deisinger
    A Virtual Environment (VE) presents a complex problem with interesting non-trivial challenges for software development. The majority of existing systems supporting VE are based on monolithic architectures, making maintenance and software reuse difficult at best. When a novel concept or idea requires implementation, it is not possible to extend an existing system by replacing or incrementing the necessary functionality. This leads to a proliferation of VE systems. This paper identifies some of the major problems in the current development trend of VE systems that result in incremental innovation with little overall progress. However, component methodology and other software engineering principles are not widely employed in system design. We present the Java Adaptive Dynamic Environment (JADE) as an innovative design approach to building VE systems. The paper discusses some of the major elements of the JADE component framework, such as the kernel, the namespace, the event model and how to configuration takes place. In addition, a simple maze dungeon game is discussed demonstrating the runtime reconfiguration of the supporting VE system.
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    Computing Dynamic Changes to BSP Trees
    (Blackwell Science Ltd and the Eurographics Association, 1992) Chrysanthou, Y.; Slater, M.
    This paper investigates a new method for dynamically changing Binary Space Partition (BSP) trees. A BSP tree representation of a 3D polygonal scene provides an ideal data structure for rapidly performing the hidden surface computations involved in changing the viewpoint. However, BSP trees have generally been thought to be unsuitable for applications where the geometry of objects in the scene changes dynamically. The purpose of this paper is to introduce a dynamic BSP tree algorithm which does allow for such changes, and which maintains the simplicity and integrity of the BSP tree representation. The algorithm is extended to include dynamic changes to shadows. We calibrate the algorithms by transforming a range of objects in a scene, and reporting on the observed timing results.
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    An Eye Gaze Model for Dyadic Interaction in an Immersive Virtual Environment: Practice and Experience
    (The Eurographics Association and Blackwell Publishing Ltd., 2004) Vinayagamoorthy, V.; Garau, M.; Steed, A.; Slater, M.
    This paper describes a behavioural model used to simulate realistic eye-gaze behaviour and body animations for avatars representing participants in a shared immersive virtual environment (IVE). The model was used in a study designed to explore the impact of avatar realism on the perceived quality of communication within a negotiation scenario. Our eye-gaze model was based on data and studies carried out on the behaviour of eye-gaze during face-to-face communication. The technical features of the model are reported here. Information about the motivation behind the study, experimental procedures and a full analysis of the results obtained are given in [17].