| Cognitive ability and information retrieval: When less is more | | BIBAK | Full-Text | 1-7 | |
| S. J. Westerman; T. Cribbin | |||
| This paper is concerned with the use of virtual environments as a means of
conveying semantic information relating to the contents of computerised textual
databases. two empirical studies are reported that investigated the influence
of individual differences in cognitive ability on search task performance. In
the first experiment, objects (each representing a type of animal) were placed
ordinally in a three-dimensional cube arrangement based on ratings of semantic
similarity. Participants were required to locate a series of randomly selected
objects. Contrary to prediction, participants with high associative memory were
comparatively poorer performers. In a second experiment 'true' rating distances
were used to locate objects in virtual space. High spatial ability was
associated with better performance and, in contrast with the results of
Experiment 1, this pattern also was replicated for associative memory.
Implications are discussed. Keywords: Individual Differences; Information Retrieval; Visualisation | |||
| VoxColliDe: Voxel collision detection for virtual environments | | BIBAK | Full-Text | 8-22 | |
| S. M. Lock; D. P. M. Wills | |||
| Collision detection is fundamental in achieving natural dynamics in virtual
environments, but current algorithms are too slow, causing a major bottleneck
in processing and hindering the building of interactive simulation
environments. This paper provides an overview of the collision detection
problem and current attempted solutions. A voxel-based approach to rigid-body
collision detection is presented, with its potential high performance
explained.
Voxel collision detection takes place on a pair-wise basis, involving two additional representations of a polygonal object, a Voxmap and a Point Shell. These are constructed in a pre-processing step and allow fast collision detection through a simple look-up reference of points into voxels. Collision performance depends upon the number of points in the shell, and can trade accuracy for speed. A range of pruning techniques, needed to cut down the number of objects undergoing collision testing, are reviewed and implemented. These allow most effective use of the voxel collision detection algorithm in multi-body simulations, such as virtual environments. Performance evaluations demonstrate the voxel collision detection algorithm's ability to achieve interactive rates (above 20 Hz) for both high precision pair-wise collision tests, and for large numbers of objects in multi-body environments. The voxel collision detection algorithm is suitable for parallel, hardware implementation. This provides the potential for great enhancements to already extremely high performance, rendering the voxel-based approach to collision detection all the more promising. Keywords: Collision detection; Presence; Virtual environments; Voxel | |||
| Intelligent Cruise-Control Navigation: A new navigation/travel method for use in virtual environments | | BIBAK | Full-Text | 23-31 | |
| Tae-Wook Kwon; Yoon-Chul Choy | |||
| An important feature of virtual reality is the facility for the user to move
around a virtual environment in a natural and easily controlled manner.
Navigation, also called locomotion, travel or motion, involves changing the
perspective of the user in the virtual environment (VE). It allows the user to
move in the VE as well as reorient themselves to look at the world differently.
Natural locomotion methods are able to contribute to a sense of presence and
reality. The illusion of presence can be lost through unnatural experiences
during travel in the VE. This can be caused by poor interactive metaphors or by
experiences which do not agree with the user's everyday understanding of the
real world. This paper focuses on the navigation method in the VE, one of the
major interfaces for the interactivity between human and VE in virtual reality
circumstances and worlds. It proposes a new navigation method. Intelligent
Cruise-Control Navigation (ICCN), which provides a natural and user-centred
approach to navigation in the VE and can improve the user's sense of reality
and presence. ICCN is composed of three major phases: Constant Velocity
Navigation, Collision Detection and Avoidance, and Path Adjustment. The ICCN
can reduce the user's fatigue and improve the user's presence in the VE. The
small experimental study reported in this paper suggests that the ICCN will be
a natural, straightforward, and useful navigation interface in VE. Keywords: Collision detection and avoidance; Constant velocity navigation; Hands-free
navigation; Intelligent cruise-control navigation; Locomotion; Navigation; Path
adjustment; Travel | |||
| The need for a socio-cultural perspective in the implementation of virtual environments | | BIBAK | Full-Text | 32-38 | |
| G. Riva; G. Mantovani | |||
| For many researchers, virtual reality (VR) is first of all a technology.
This vision is also well reflected in the growing research work concerned with
virtual environments: most of it has been addressed primarily the development
of new rendering technologies rather than the highly interactive and dynamic
nature of user-system interaction that VR supports. However, this focus on
technology is disappointing for developers and researchers. To overcome this
limitation, this paper describes VR as an advanced communication tool: a
communication interface in single-user VR, and a communication medium in the
case of multi-user VR. This leads us to propose a cultural concept of presence
as a social construction. Lying at the base of this view are two elements that
guarantee an elevated sense of presence: acultural framework and the
possibility of negotiation, both of actions and of their meaning. Within this
view, experiencing presence and telepresence does not depend so much on the
faithfulness of the reproduction of 'physical' aspects of 'external reality' as
on the capacity of simulation to produce a context in which social actors may
communicate and cooperate. The consequences of this approach for the design and
the development of VR systems are presented.
The first author is responsible for the preparation of Section 3. The second author prepared Section 2. Introduction and Conclusions were prepared by both authors. Moreover, to both authors must be attributed the definition of contents and the final structure of the paper. Keywords: Communication; Presence; Social construction | |||
| Experimental research into human cognitive processing in an augmented reality environment for embedded training systems | | BIBAK | Full-Text | 39-46 | |
| R. S. Kalawsky; K. Hill; A. W. Stedmon; C. A. Cook; A. Young | |||
| Research into human factors issues associated with the use of augmented
reality (AR) technology is very limited. Consequently, there is a need for
formal human factors design guidelines to underpin the integration of AR into
systems. The Defence Evaluation and Research Agency (DERA) Centre for Human
Sciences (CHS) is evaluating the potential of AR for providing real-time
training feedback in future advanced embedded training systems for the
military. In order to understand the important human factors issues of
augmented reality, DERA funded the Advanced VR Research Centre (AVRRC) at
Loughborough University to investigate the cognitive ergonomics of this
technology. An important aspect of this research is concerned with identifying
any human information processing issues that may arise when information is
presented via AR and overlaid upon one or more primary display surfaces such as
a visual display unit (VDU). Two main issues are addressed in this research.
First, the impact of AR on human information processing and second, subjective
workload experienced when displaying information via the AR medium. The
experiments reported in this paper assess issues of reaccommodation and
reaction times to alarms on different display formats. They demonstrate also
that AR performs as well as standard display formats. Keywords: Augmented reality; Cognitive processing; Human performance; Training;
Virtual reality | |||
| Enhanced avatar control using neural networks | | BIBAK | Full-Text | 47-53 | |
| H. Amin; R. A. Earnshaw | |||
| This paper presents realistic avatar movements using a limited number of
sensors. An inverse kinematics algorithm, SHAKF, is used to configure an
articulated skeletal model, and a neural network is employed to predict the
movement of joints not bearing sensors. The results show that the neural
network is able to give a very close approximation to the actual rotation of
the joints. This allows a substantial reduction in the number of sensors to
configure an articulated human skeletal model. Keywords: Inverse kinematics; Motion capture; Neural network | |||
| Guest editorial -- Applying agent technology to Virtual Reality: Intelligent virtual agents | | BIB | Full-Text | 55-56 | |
| R. Aylett; D. Ballin | |||
| Dragons, bats and evil knights: A three-layer design approach to character-based creative play | | BIBAK | Full-Text | 57-71 | |
| J. Bryson; K. R. Thórisson | |||
| Creative play requires a fertile but well-defined design space. This paper
describes a design process for creating three-dimensional virtual reality play
spaces that allow the development and exploration of social interactions and
relationships. The process was developed as part of a commercial research
effort to create an interactive virtual reality entertainment system that
allows children to engage in creative and constructive play within an
established action/adventure framework. The effort centres on designing Al
characters for a constructive narrative. We claim that a behaviour-based
architecture is an ideal starting point for developing agents for such a
process, but that its full realization requires additional architectural
structures and methodological support for the design process. In this paper, we
describe a character architecture called Spark of Life (SoL). We also propose a
three-layer design process for producing fertile and aesthetic constructive
narratives. Finally, we describe our experience in implementing these ideals in
an industrial setting. Keywords: Behaviour-based Al; Character architectures; Constructive narrative; Design
team methodology; Personality and action selection | |||
| Collision avoidance and map construction using synthetic vision | | BIBAK | Full-Text | 72-81 | |
| P. Monsieurs; K. Coninx; E. Flerackers | |||
| In this paper, we present a method to implement a navigation system for an
intelligent agent that exists in a virtual world to generate collision-free
motion. To observe the world, the agent uses virtual sensors consisting of the
depth buffer information of a rendered image of the scene. This information is
used to generate low-level collision avoidance, obstacle avoidance when moving
to intermediate goals, and to create an accessibility graph and an obstacle map
of the environment. The agent does not require access to the internal
representation of the virtual world, which is similar to perception in mobile
robots in the real world. Furthermore, the algorithm used is fast enough to
work in real time. Keywords: Collision avoidance; Map construction; Navigation; Synthetic vision | |||
| The virtual interactive presenter: a conversational character for interactive television | | BIBAK | Full-Text | 82-94 | |
| M. Cavazza; T. Robinson; S. Francis; W. Perotto; N. Cashman | |||
| This paper describes the development of a conversational interface for
interactive TV. With the advent of multi-channel digital TV, accessing
Electronic Programme Guides (EPGs) will become increasingly complex. We claim
that a conversational interface can support incremental refinement of user
selections, thus assisting user choice without requiring extensive knowledge of
the editorial categories used in the EPG. We present the system architecture
and describe the building blocks of this system in terms of underlying
technologies, namely speech recognition, Natural Language Processing, dialogue
modelling, character animation and multi-modal presentation. The use of an
animated character appears to influence the implementation of each of these
basic techniques. After giving an overview of the system behaviour and
architecture, we describe the various building blocks of a conversational agent
as implemented in our system and to what extent each of the underlying
technologies are influenced by the use of a conversational character. We report
current results by describing example dialogues from the system. Finally, we
compare our approach with other interface agents' paradigms. Keywords: Human-Computer dialogue; Conversational characters; Speech understanding;
Interface agents | |||
| A high-level architecture for believable social agents | | BIBAK | Full-Text | 95-106 | |
| A. Guye-Vuillème; D. Thalmann | |||
| The creation of virtual humans capable of behaving and interacting
realistically with each other requires the development of autonomous believable
social agents. Standard goal-oriented approaches are not well suited to it
because they don't take into account important characteristics identified by
the social sciences. This paper tackles the issue of a general social reasoning
mechanism, discussing its basic functional requirements using a sociological
perspective, and proposing a high-level architecture based on Roles, Norms,
Values and Types. Keywords: Socially believable agents; Socially intelligent virtual agent | |||
| A Synthetic Actor model for long-term computer games | | BIBAK | Full-Text | 107-116 | |
| D. R. Silva; C. A. Siebra; J. L. Valadares; A. L. Almeida; A. C. Frery | |||
| Virtual Reality and Artificial Intelligence provide suitable techniques to
improve computer games quality. While the former offers mechanisms to model
environment and characters' physical features, the latter provides models and
tools for building characters, namely Synthetic Actors or Believable Agents,
which can exhibit intelligent social behaviour and express personality and
emotions. The current architecture proposals for Synthetic Actors do not fully
meet the requirements for long-term games development, such as strategy and
adventure ones, it is necessary to guarantee both personality stability and
reactive emotional responses, which may be contradictory. In this work, we
propose a new Synthetic Actor model that tightly connects emotions and social
attitudes to personality, providing a long-term coherent behaviour. This model
has been applied to two games presented here as case studies. Keywords: Computer games; Intelligent agents; Personality; Synthetic actors | |||
| An overview of physically-based modelling techniques for virtual environments | | BIBAK | Full-Text | 117-131 | |
| P. M. Chapman; D. P. M. Wills | |||
| A class of virtual environments is concerned with the representation of
behaviour that is apparent in the real world. In order to model this behaviour,
sophisticated physical models are required. The development of these models,
classed asphysically-based modelling, is based upon the fundamental concepts of
Newtonian dynamics. Considerable research into physically-based modelling has
already been conducted by the computer graphics community, permitting realistic
animation of object motion. The application of physical models to virtual
environments poses further problems, not least that of real-time execution in a
fully interactive environment. This paper gives an overview of the existing
computer graphics research concerned with physically-based modelling,
discussing the merits and problems of various techniques in terms of the
requirements of virtual environment. Keywords: Collision detection and response; Physically-based modelling, Rigid and
non-rigid dynamics; Virtual environments | |||
| An adaptive dead reckoning algorithm using update lifetime | | BIBAK | Full-Text | 132-148 | |
| S-J. Yu; Y-C. Choy | |||
| This paper proposes a new, adaptive Dead Reckoning algorithm, called Dynamic
Dead Reckoning, for distributed interactive simulation and humanoid avatar
systems. The proposed model can overcome the weak points of traditional Dead
Reckoning caused by a fixed threshold and a strong dependency on rotation
behaviour of entity. This paper introduces a new criterion for update message
filtering, named as state update lifetime, which is a valid duration time of
entity state update. The Dynamic Dead Reckoning has the advantage of keeping
the balance between filtering performance and extrapolation fidelity using two
major components, variable threshold mechanism and rotation event model. The
experimental results show that the proposed algorithm can lower the increment
rate of update traffic with the increase of rotation frequency without any
significant loss of accuracy. Keywords: Adaptive algorithm; Dead Reckoning; Entity state update; Rotation behaviour;
Variable threshold | |||
| Enabling trust formation within agent-mediated virtual environments | | BIBAK | Full-Text | 149-159 | |
| P. Papadopoulou; A. Andreou; P. Kanellis; D. Martakos | |||
| In e-commerce, the role of trust becomes vital for establishing and
maintaining customer relationships. Drawing from established theoretical work
on trust and relationship marketing, this paper synthesises a series of trust
constructs, determinant variables and trust building processes, and proposes a
framework for the formation of trust in customer-business relationships. The
framework is conceptualised in the context of an electronic servicescape, where
trust is formed through iterative interactions with promises being made,
enabled and fulfilled. Based on this framework, the paper illustrates how the
application of agent and virtual reality technologies can provide the
environment and facilitate the expressiveness demanded by such a servicescape. Keywords: Agents; E-commerce; Trust; Virtual Environments | |||
| Haptic Cooperative Virtual Workspace: Architecture and evaluation | | BIBAK | Full-Text | 160-168 | |
| M. O. Alhalabi; S. Horiguchi | |||
| The Haptic Cooperative Virtual Workspace (HCVW), where users can
simultaneously manipulate and haptically feel the same object, is beneficial
and in some cases indispensable for training a team of surgeons, or in
application areas in telerobotics and entertainment. In this paper we propose
an architecture for the haptic cooperative workspace where the participants can
kinesthetically interact, feel and push each other simultaneously while moving
in the simulation. This involves the ability to manipulate the same virtual
object at the same time. A set of experiments carried out to investigate the
haptic cooperative workspace is reported. A new approach to quantitatively
evaluate the cooperative haptic system is proposed, which can be extended to
evaluate haptic systems in general. Keywords: Cooperative system architecture; Haptic cooperative applications; Haptic
cooperative virtual workspace; Haptic | |||
| A survey of electromagnetic position tracker calibration techniques | | BIBAK | Full-Text | 169-182 | |
| Volodymyr V. Kindratenko | |||
| This paper is a comprehensive survey of various techniques used to calibrate
electromagnetic position tracking systems. A common framework is established to
present the calibration problem as the interpolation problem in 3D. All the
known calibration techniques are classified into local and global methods and
grouped according to their mathematical models. Both the location error and the
orientation error correction techniques are surveyed. Data acquisition devices
and methods as well as publicly available software implementations are
reviewed, too. Keywords: Electromagnetic position tracking; Tracker calibration; Virtual reality | |||
| Computer games | | BIB | Full-Text | 183-184 | |
| S. Maddock | |||
| Computer games technology and higher education | | BIBAK | Full-Text | 185-194 | |
| A. Watt; S. Maddock | |||
| The motivation of this paper is to debate the issue of how we should treat
computer games technology in higher education. Certainly it is the case that
computer games technology is a new and demanding profession. It is also the
case that there has been a slow realisation within the academic community of
both the depth and the importance of the topic. The issues are obvious. What
exactly comprises computer games technology and should it be considered as a
separate academic topic for a degree course or be a set of options within an
established undergraduate degree structure? And who is responsible for pushing
forward research in the subject? Within the framework of this debate we will
present our work at the University of Sheffield. Keywords: Computer games technology; Education | |||
| Games development in VRML | | BIBAK | Full-Text | 195-203 | |
| L. Jankovic | |||
| Web 3D technologies have developed very rapidly over the past few years
resulting in, for example, the standardisation of the Virtual Reality Modelling
Language (VRML97). Although such technologies have the infrastructure for
considerable improvements of games products, they have not yet taken off as
games development languages. Inspired by teaching a Virtual Reality module in
the School of Computer Science at Birmingham, where typically 30% of the
students choose to develop games in VRML for their practical work, the author
describes some of the students' games projects and looks into the educational
aspects, advantages, limitations and desired features of VRML for games
development. Keywords: Computer programming; Education; Games development; Virtual Reality; VRML;
Web 3D | |||
| The computer game industry: Current state of play | | BIBAK | Full-Text | 204-214 | |
| I. Badcoe | |||
| The computer games industry suffers from a no-longer justified reputation
for chaotic and unprofessional software development. This paper describes the
current state of the evolving art of games software, and then outlines the
precise areas of technique of current interest for development, and research
purposes. Keywords: Audio processing; Games Rendering; Simulation; Software development | |||
| Online and multiplayer gaming -- An overview | | BIBAK | Full-Text | 215-222 | |
| T. Cox | |||
| This paper gives a broad overview of the technology and market for on-line
and multiplayer computer gaming. Some economic considerations and their
influence on the choice of technologies are examined. Particular attention is
given to the 'massively-multiplayer' and 'persistent world' type of games, and
the special problems that arise in these environments. Lastly, some ongoing
problems are investigated, particularly the thorny issue of cheating in
multiplayer games. Keywords: Games; Internet; Multiplayer; Online | |||
| Al in computer games: Survey and perspectives | | BIBAK | Full-Text | 223-235 | |
| M. Cavazza | |||
| Computer games have traditionally implemented empirical solutions to many Al
problems and are now turning to more traditional Al algorithms. After
introducing the role of Al in gameplay, we review the main techniques used in
current computer games such as Finite-State Transition Networks, rule-based
systems and search algorithms. We describe the implementation of Al in several
commercial computer games, as well as academic research in Al targeting
computer games applications. We conclude this review by discussing future
trends and proposing research directions. Keywords: Artificial intelligence; Computer games; Intelligent agents; Planning;
Virtual Humans | |||
| The console market | | BIBAK | Full-Text | 236-244 | |
| J. Kirriemuir | |||
| The home-based video games market is one of the largest within the
entertainment industry, and has recently begun to rival the music and film
sectors in terms of audience, sales and revenue. This is partially due to the
high profile mass marketing of games consoles and titles over the last decade,
especially by a trio of Japanese electronics companies (Nintendo, Sega and
Sony); however, it is also due to the increasing complexity, visual
attractiveness and interactivity of contemporary video games.
In this paper, we identify a number of characteristics pertaining to games consoles and game development. Following this, we examine the state of the console market as of the summer of 2001, focusing on the main manufacturers, their consoles, and how they may fare in the near future. Keywords: Business; Console; Entertainment; Gaming; On-line; Video | |||