Virtual Environment Research Papers - Academia.edu (original) (raw)

We collected mobility traces of 84,208 avatars spanning 22 regions over two months in Second Life, a popular networked virtual en- vironment. We analyzed the traces to characterize the dynamics of the avatars mobility and behavior, both temporally and spatially. We discuss the implications of the our findings to the design o f peer-to-peer networked virtual environments, interest management, mobility

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- Second Life, Virtual Environment, Mobile Peer-to-Peer Network, Peer to Peer

Diverse views have highlighted the use of audio to foster learning and cognition in blind children. The idea is to use computer sound and voice to explore audio senses as vehicles for knowing and thinking. Most studies have explored the impact of audio on general domain cognitive processes. A few studies have explored specific domains such as mathematics. This study presents the design, development, and usability evaluation of an audio-based virtual environment to enhance learning of mathematics knowledge in blind children. After interacting with the software we found that blind children were highly motivated and enjoyed the experience. We also observed that they solved problems and learned basic mathematics knowledge such as addition, subtraction, and cardinality. Our preliminary results indicate that audio-based virtual environments can help to ameliorate the complexity of blind children learning mathematics.

- by Jaime Calbucan Sanchez
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- Virtual Environment, Usability Evaluation, Cognitive Process

Research is divided about the potential of e-service to bridge communication gaps, particularly to diverse user groups. According to the existing body of literature, e-service may increase or decrease the quality of service received. This study analyzes the level of service received by different genders and ethnic groups when public librarians answer online reference queries. Quality of e-service was evaluated along three dimensions: responsiveness, reliability, and courtesy. This study found no significant differences among different user groups along any of these dimensions, supporting the argument that the virtual environment facilitates equitable service and may overcome some challenges of diverse user groups.

- by Shannon Oltmann
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- Virtual Environment, Quality of Service, Ethnic Group, Level of Service

Motek Medical's CAREN-Extended system is a virtual environment primarily used in physical rehabilitation and biomechanical research. This virtual environment integrates a motion capture system and a six degree of freedom motion platform equipped with a dual-belt treadmill and two force plates. This research describes performance characteristics associated with a "treadmill -motion platform" configuration that should be considered for appropriate measurement, and effective design of research protocols and rehabilitation CAREN applications.

- by Edward Lemaire and +1
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- Virtual Reality, Virtual Environment, Physical Rehabilitation, Treadmill

This paper explores the Web 2.0 ethos with respect to the application of pedagogy within 3D online virtual environments. 3D worlds can create a synthetic experience capturing the essence of being in a particular world or context. The AliveX3D platform adopts the Web 2.0 ethos and applies it to online 3D virtual environment forming a Web 2.0/Web3D hybrid that has wider usability than previous alternatives. This combined with the AliveX3D Scene Editor allows learning experiences, which are controlled by the learner, appear authentic and facilitate collaboration conversations to be developed simultaneously. This immersion enables learners to negotiate meaning based on their own personal cognitive, affective and kinaesthetic experiences rather than on the descriptions of others’ experiences. We conclude by suggesting the choices embedded within the worlds allow the learning focus to shift away from isolated pre-designed interactions, to a situation that encourages the learner to control...

Immersive virtual environments (VEs) offer interactive, real-time visualization capabilities for engineers, architects, and scientists. This paper presents Virtual-SAP, an immersive VE application allowing users to assess building structures and their response to various environmental conditions through an interactive designbuild-test-redesign cycle. Virtual-SAP has three distinct user interfaces that support its use with a high-end, multitracker VE system, with a low-cost portable VE system, or on the desktop. Two of these interfaces have been proven highly usable in user testing, and the third will be tested soon. Virtual-SAP is being used for both research and education.

We present blue-c, a new generation immersive projection and 3D video acquisition environment for virtual design and collaboration. It combines simultaneous acquisition of multiple live video streams with advanced 3D projection technology in a CAVE™like environment, creating the impression of total immersion. The blue-c portal currently consists of three rectangular projection screens that are built from glass panels containing liquid crystal layers. These screens can be switched from a whitish opaque state (for projection) to a transparent state (for acquisition), which allows the video cameras to "look through" the walls. Our projection technology is based on active stereo using two LCD projectors per screen. The projectors are synchronously shuttered along with the screens, the stereo glasses, active illumination devices, and the acquisition hardware. From multiple video streams, we compute a 3D video representation of the user in real time. The resulting video inlays are integrated into a networked virtual environment. Our design is highly scalable, enabling blue-c to connect to portals with less sophisticated hardware.

- by ga la
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- Information Systems, Video Streaming, Virtual Environment, Real Time

Our project used a virtual environment called DarkCon to simulate a military reconnaissance mission. In this study, we investigated the differential effects of priming on a group of 34 Army Ranger "recycles" from Fort Benning, GA. Half were given a military-style, and half a game-style instructional video and briefing. We tested subjects for simulatorsickness, immersive tendencies, self-reported degree of presence, and recall of scenario elements. We hypothesized that the priming condition would result in different behavior within the virtual environment, and possibly differences within subjects' recall of their experience. We also examined the effects of subjects' prior game play experience and habits on their behavior. Implications of our findings and directions for future research are discussed.

- by Donat-Pierre Luigi
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- Virtual Reality, Virtual Environment

This paper describes a study to examine how a social situation can be simulated in a virtual environment, and how to provoke the same behavioral response as in a real life social situation. The aim is to create new Virtual Reality worlds for treating social phobia. Two cases were examined in a virtual environment to assess whether it was able to recreate social behavior of people. First, we examined if participants who enter a crowded room in the virtual environment prefer to take a seat in a chair that is close to them. ...

- by Fatma İnan düdükcü
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- Anxiety Disorders, Cyberpsychology, Social Anxiety, Virtual Worlds

Exploring unknown models or scenes is a highly interactive and dynamic process. Systems for automatic presentation of models or scenes either require cinematographic rules, direct human interaction, framesets, or precalculation of paths to a known goal. In this paper we present a system which can deal with rapidly changing user interest in objects of a scene or model as well as with dynamic models and changes of the camera position introduced interactively by the user or through cuts. We describe CubicalPath, a new potential field-based camera control system that helps with the exploration of virtual environments.

- by Steffi Beckhaus
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- Animation, Virtual Environment, Human Interaction, CGF

In the view of escalating global threat in security, it is imperative to have an automated detection system that can pick up suspicious patterns of human movement in physical environments. It can give a forewarning before a planned attack happens or an ultimate security is breached. In the past, significant research on the Intrusion Detection was established, but limited to virtual environments like computer networks and operating systems. In this paper, we proposed a general security model for detecting suspicious patterns in physical environment. Suspicious patterns are subtle and we showed that they can be detected via an experiment.

- by Escal Global
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- Computer Networks, Servant Leadership, Applied Research, OPERATING SYSTEM

Massively multiuser online games such as World of Warcraft employ computer controlled non-player characters and quest activities extensively in training/tutoring capacities. This approach is very effective and popular, incorporating active learning, incremental progress, and creative repetition. This paper explores ways to exploit this model in educational virtual environments. Non-player characters in such environments require a knowledge model, a dialogue model, and a user performance model, in addition to any physical and behavioral traits necessary to make them interesting and credible members of the environment.

- by Clinton Jeffery
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- Active Learning, Second Life, Virtual Learning Environments, Virtual Environment

This paper presents a haptic virtual reality tool developed to enhance the accessibility for the visually impaired. The proposed approach focuses on the development of a highly interactive haptic virtual reality system that allows visually impaired, to study and interact with various virtual objects in specially designed virtual environments. The system is based on the use of the CyberGrasp™ and the PHANToM™ haptic devices. A number of custom applications have been developed based on object recognition and manipulation, and utilizing the advantages of both haptic devices. The system has been tested and evaluated in three custom training applications for the visually impaired.

- by Serafeim Moustakidis
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- Virtual Reality, Virtual Environment, Object Recognition, Visual Impairment

The analysis of granulometry of substances is relevant in a great variety of the research and industrial applications. Unfortunately, image-based algorithms for granulometry analysis are difficult to tune and validate. In a typical setup, one or more cameras acquire images of a scene with a great number of objects or particles that must be measured. The distribution of the sizes/shape characteristics of the elements are the common output of such systems. The creation of supervised image database where the coordinates of all elements are known is very important and it allows for testing in a suitable manner the final size/shape distribution of particles produced by the image processing system with respect to the real distribution. Due to the great amount of objects or particles in the images, it is not often convenient, or even impossible, to individually measure each single objects in order to test the capability of the image processing system to locate and measure the elements (creation of a supervised dataset). One possible solution encompasses the creation of a synthetic image dataset where the position of each elements is known a priori. In this paper we propose a virtual environment to create and test an imagebased granulometric system based on the 3D engine Blender. Results are encouraging and show the effectiveness of the proposed method.

- by Vincenzo Piuri
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- Image Processing, Image Analysis, Virtual Reality, Virtual Environment

We present an interactive algorithm to perform continuous collision detection between general deformable models using graphics processors (GPUs). We model the motion of each object in the environment as a continuous path and check for collisions along the paths. Our algorithm precomputes the chromatic decomposition for each object and uses visibility queries on GPUs to quickly compute potentially colliding sets of primitives. We introduce a primitive classification technique to perform efficient continuous self-collision. We have implemented our algorithm on a 3.0 GHz Pentium IV PC with a NVIDIA 7800 GPU, and we highlight its performance on complex simulations composed of several thousands of triangles. In practice, our algorithm is able to detect all contacts, including self-collisions, at image-space precision in tens of milli-seconds. r

- by Ming Lin
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- Virtual Environment, Collision detection

Aerospace industry has been involved in virtual simulation for design and testing since the birth of virtual reality. Today this industry is showing a growing interest in the development of haptic-based maintenance training applications, which represent the most advanced way to simulate maintenance and repair tasks within a virtual environment by means of a visual-haptic approach. The goal is to allow the trainee to experiment the service procedures not only as a workflow reproduced at a visual level but also in terms of the kinaesthetic feedback involved with the manipulation of tools and components. This study, conducted in collaboration with aerospace industry specialists, is aimed to the development of an immersive virtual capable of immerging the trainees into a virtual environment where mechanics and technicians can perform maintenance simulation or training tasks by directly manipulating 3D virtual models of aircraft parts while perceiving force feedback through the haptic interface. The proposed system is based on ViRstperson, a virtual reality engine under development at the Italian Center for Aerospace Research (CIRA) to support engineering and technical activities such as design-time maintenance procedure validation, and maintenance training. This engine has been extended to support haptic-based interaction, enabling a more complete level of interaction, also in terms of impedance control, and thus fostering the development of haptic knowledge in the user. The user's "sense of touch" within the immersive virtual environment is simulated through an Immersion CyberForce® hand-based force-feedback device. Preliminary testing of the proposed system seems encouraging.

A previous study indicated that peripheral visual information strongly affects the judgment of egocentric distances for users of immersive virtual environments. The experiment described in this document aimed to investigate if these effects could be explained in terms of changes in gait caused by visual information in the extreme periphery. Three conditions with varying degrees of peripheral occlusion were tested and participants' walking characteristics measured. The results indicate that the improvements in distance ...

Data Mining has become a major academic research area over the last ten years. However, in the transition from academic prototypes to commercial products there have been few successes with commercial Data Mining applications failing to... more

Unilateral spatial neglect is defined as a disorder in which a patient fails to pay attention to stimuli presented to the contralateral side of the lesion; it is known to be associated with decreased functional independence. Our objective was to determine the suitability and feasibility of using a PC-based, non-immersive VR system for training individuals with unilateral spatial neglect to cross streets in a safe and vigilant manner. A virtual environment, consisting of a typical city street, was programmed via Superscape's 3D-Webmaster, a 3D web-authoring tool. Twelve subjects, aged 55 to 75 years, participated. Results demonstrated that this virtual environment was suitable in both its cognitive and motor demands for the targeted population. With very few exceptions, the control subjects were able to complete all levels of the program with success. The performance of the patient subjects was considerably more variable, and they were able to complete fewer levels, and usually took more time to do so. The results indicate that the virtual reality training is likely to prove beneficial to people who have difficulty with street crossing.

The interaction models found in typical desktop virtual environments designed for social interactions need to be improved in order to provide an adequate sense of embodiment and appropriate levels of abstraction for collaborative tasks. In order to improve the kinds of user interfaces available in social desktop virtual environments, new mechanisms for embodied interaction are needed. Such mechanisms would allow the dynamic generation of user interface displaying currently available high-level actions that can be performed on objects. This paper evaluates the kinds of interactions currently available in social desktop virtual environments, explores how these interactions effect the end-user experience, and suggests possible solutions for improving a user's sense of embodiment and presence in such environments.

- by Elisabeth Cuddihy
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- Social Interaction, User Interface, User eXperience, Virtual Environment

The development of intelligent environments poses complex challenges, namely at the level of device heterogeneity and environment dynamics. In fact, we still lack supporting technologies and development approaches that can efficiently integrate different devices and technologies. In this paper we present how a recent integration of two important technologies, OSGi and Jade, can be used to significantly improve the development process, making it a more dynamic, modular and configurable one. We also focus on the main advantages that this integration provides to developers, from the Ambient Intelligence point of view. This work results from the development of two intelligent environments: VirtualECare, which is an intelligent environment for the monitorization of elderly in their homes and UMCourt, a virtual environment for dispute resolution.

Literature on virtual reality (VR) and psychology has focused on the influence that some ba¬ sic psychological processes have on VR. Although psychological processes may be defined as common to all humans, there are individual differences that might make it difficult to pro¬ vide the same VR experience for everyone. Of the several personality and psychological vari¬ ables that might be relevant to the VR field, this study focuses on two: absorption and dis¬ sociation. Both psychological dimensions are deeply interrelated and might play an important role in the immersion of subjects in virtual environments and in the reality attributions they make. Thus, the purpose of this study was to ascertain personality correlates on differences regarding the VR experience. The subjects were 39 psychology undergraduate students who were immersed in a VR environment for 15 minutes. Our data suggest that both absorption and dissociation influenced central issues regarding reality judgment in VR. side, NJ: Lawrence Erlbaum.

- by Cristina Botella
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- Information Systems, Psychology, Cognitive Science, Cyberpsychology
- by Pascal Sockeel and +2
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- Psychology, Adolescent, Down Syndrome, Learning

Technology has always introduced changes in the way researchers administer surveys. A new technology known as virtual worlds has now emerged that promises to change data collection once again. Virtual worlds are persistent, online, computer-rendered spaces populated by hundreds, thousands, or even millions of people at a time. Previously, this population has only been surveyed in ways that required respondents to exit the virtual world before giving their answers. No survey method has existed whereby they could be surveyed while remaining present in the virtual space. Needless to say, this is less than ideal for any survey about the respondent's attitudes, perceptions, and behavior within the virtual world itself. This study introduces a method for solving this problem and a tool that allows surveys entirely within a virtual environment. The method is introduced as Virtual Assisted Self Interview (VASI), and the tool for implementing it, the Virtual Data Collection Interface (VDCI). The tool was created and deployed in the virtual world Second Life (SL), where users were asked questions about demographics and quality of life. The valid response numbers for the survey (N=2094) make it the largest in-virtual-world data collection seen so far. This paper discusses the VDCI and describes several different sampling methods, as well as results that provide unique, new insights into virtual world populations. It is found, for example, that the demographic make-up of SL is unlike that of other virtual worlds. Moreover, the SL population is unlike that of other worlds in its approach to gender-switching. The limitations and new hazards of virtual world survey research are also discussed, especially survey "hacking" by individuals hoping to exploit the survey for financial gain. Despite the challenges, the results generally suggest that the VDCI is a valuable new research tool for obtaining representative data on virtual world population.

- by Edward Castronova
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- Quality of life, Survey Research, Virtual Worlds, Survey Methods

In this paper, we propose a new integration approach to simulate an Autonomous Virtual Agent's cognitive learning of a task for interactive Virtual Environment applications. Our research focuses on the behavioural animation of virtual humans capable of acting independently. Our contribution is important because we present a solution for fast learning with evolution. We propose the concept of a Learning Unit Architecture that functions as a control unit of the Autonomous Virtual Agent's brain. Although our technique has proved to be effective in our case study, there is no guarantee that it will work for every imaginable Autonomous Virtual Agent and Virtual Environment. The results are illustrated in a domain that requires effective coordination of behaviours, such as driving a car inside a virtual city. 1. The design of a learning control structure, 2. The internal storage of the learning information and 3. The efficient evaluation and calculation of feedbacks and reactions from the environment.

- by Ruth Aylett
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- Artificial Intelligence, Computer Animation, Modeling, User Interface

One of the major goals in the development of virtual environments in recent years has been to create more and more realistic scenery, characters and natural human forms of interaction with the environment. We question this approach especially for the domain of computer games for two main reasons. Firstly we argue the following: When the absolute difference between reality and virtual environments decreases one would expect the latter to become increasingly believable for a spectator. Paradoxically often the opposite is true since the attention of the spectator gets drawn to the remaining differences to a greater extent. Secondly we ask ourselves why of all things computer games which are created for entertainment should be limited with real world constraints and are not used to experience features that are only possible in virtual environments. We conclude with a 'manifesto' for the renovation of computer games.

- by Stefan Grünvogel
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- Virtual Environment

An object-oriented event-driven virtual environment (VE) for viewing the simulation results of¯exible multibody systems (FMS) is developed. The VE interfaces with the following output devices: immersive stereoscopic screen(s) and stereo speakers; and a variety of input devices including, head tracker, wand, joystick, mouse, microphone, and keyboard. The VE incorporates the following types of primitive software objects: user-interface objects, support objects, geometric entities, and ®nite elements. Each object encapsulates a set of properties, methods, and events that de®ne its behavior, appearance, and functions. A ªcontainerº object allows grouping many objects into one object, which inherits the properties of its ªchildrenº objects. The VE allows real-time viewing and ª¯y-throughº of photo-realistic models, vibrational mode-shapes, and animation of the dynamic motion of FMS. An application of this VE is presented for visualization of the dynamic analysis results of a large deployable space structure Ð NASA's Next Generation Space Telescope. Published by Elsevier Science Ltd.

- by Tamer Wasfy
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- Engineering, Software Engineering, User Interface, Finite Elements

The advent of the Internet is leading a re-evaluation of existing business practice as the m ethods em ployed in a non-vir tual world m ay not necessar ily be as effective in a virtual environm ent. The present paper exam ines the different strateg ic options facing organiz ations as they attem pt to build a custom er base on the Inter net. The traditional site-centric approach of directing traf® c to a central Inter net site suffers from the problem s of the increasing costs and decreasing effectiveness of Internet adver tising. An alter native strategy is the sym biotic approach which is based on the concept of m utuality. A strategy of sym biotic m arketing involves one organiz ation providing functionality for another organiz ation' s Inter net site. In exchange for the provision of functionality for another Internet site the provider bene® ts from a increased m arket coverage and reach. Although the strategy of sym biotic m arketing m ay initially appear counter-intuitive, the following paper highlights the potential adva ntages for a com pany pursuing such a strategy. The case dem onstrates such a strategy exits as a low cost m ethod of developing a custom er base on the Inter net. Finally, the potential scope of sym biotic m arketing is discussed.

- by Ian Blackman
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- Marketing, Virtual Worlds, Marketing Strategy, Strategic Marketing

The paper presents the simulation and modeling of gait on a system using two prototype compact Stewart platforms. Control issues raised by the reduced size of the robots and hence their lower power output are discussed. The flexible haptic material concept is introduced and used to realistically model heterogeneous haptic surfaces simulating the virtual ground. An algorithm for virtual foot/virtual surface contact modeling and transforming the platform motion into walking in VEs is also presented.

- by Judith Deutsch
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- Virtual Reality, Mobile Robots, Virtual Environment, Gait Analysis

Diverse studies using computer applications have been implemented to improve the learning of children with visual disabilities. A growing line of research uses audio-based interactive interfaces to enhance learning and cognition in these children. The development of short-term memory and mathematics learning through virtual environments has not been emphasized in these studies. This work presents the design, development, and usability of AudioMath, an interactive virtual environment based on audio to develop and use short-term memory, and to assist mathematics learning of children with visual disabilities. AudioMath was developed by and for blind children. They participated in the design and usability tested the software during and after implementation. Our results evidenced that sound can be a powerful interface to develop and enhance memory and mathematics learning in blind children.

- by jaime sanchez
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- Usability Testing, Virtual Environment, Computer Application, Short Term Memory

This study reports on research carried out on 105 tutors working on distance graduate courses at the Federal University of Santa Catarina (UFSC) to assess the relationship between the level of trust and the conflict management in tutors of distance learning based graduate courses at UFSC on the AVEA - Virtual Environment of Learning. The research uses descriptive and quantitative methodology. It should be highlighted that the level of trust of the whole team prevails in the relationships, which explains the adoption of the Integration style, considered the most appropriate for creative solutions in moments of conflict.

- by Patricia Freire
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- Distance Education, Higher Education, Conflict Management, Distance Learning

We describe a process for compositing a live performance of an actor into a virtual set wherein the actor is consistently illuminated by the virtual environment. The Light Stage used in this work is a two-meter sphere of inward-pointing RGB light emitting diodes focused on the actor, where each light can be set to an arbitrary color and intensity to replicate a real-world or virtual lighting environment. We implement a digital two-camera infrared matting system to composite the actor into the background plate of the environment without affecting the visible-spectrum illumination on the actor. The color reponse of the system is calibrated to produce correct color renditions of the actor as illuminated by the environment. We demonstrate moving-camera composites of actors into real-world environments and virtual sets such that the actor is properly illuminated by the environment into which they are composited.

- by Andrew Gardner
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- Information Systems, Computer Graphics, Image Processing, Reproduction

A fully-articulated visual representation of a user in an immersive virtual environment (IVE) can enhance the user's subjective sense of feeling present in the virtual world. Usually this requires the user to wear a full-body motion... more

Humans use several senses simultaneously to explore and experience the environment. On the other hand, techno-logical or human limitations often prevent computer-based systems from providing genuine multimodal displays. For-tunately, the... more

- by Davide Rocchesso
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- Auditory Display, Virtual Environment
- by Andrew Ceranowicz
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- Engineering, Computer Science, Path planning, Virtual Reality

This tutorial addresses haptic simulation, perception and manipulation of complex deformable objects in virtual environments (VE). We first introduce HAPTEX, a research project dealing with haptic simulation and perception of textiles in VEs. Then, we present state-of-the-art techniques concerning haptic simulation and rendering, ranging from physically based modelling to control issues of tactile arrays and force-feedback devices. In the section on cloth simulation for haptic systems we describe techniques for simulating textiles adapted to the specific context of haptic applications. The section concerning tactile aspects of virtual objects shows how arrays of contactors on the skin can be used to provide appropriate spatiotemporal patterns of mechanical excitation to the underlying mechanoreceptors. Finally, the last section addresses the problem of developing suitable force feedback technologies for the realistic haptic rendering of the physical interaction with deformable objec...

- by Ian R Summers
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- Haptics, Haptic Perception, Virtual Environment, Haptic Interface Design

Experience and the activities that provide it are associated with the virtual places where they were encountered and this may instil in our imagination an illusion of an environment other than where an interactive mediated environment¹ (e.g. virtual environment, virtual reality, computer game, etc.) resides (e.g. home, work or on the move). Appropriate and/or stimulating experience may encourage users to continue, or become engaged in, pursing activities in a mediated environment. The term 'staying there' is used to describe this situation of engagement. Conversely, if experience from use does not match up/deliver on expectations or purpose, or it is dull, boring, uninteresting then it may not hold user's attention and can potentially shift attention from the mediated to the real world. This paper describes the background work towards the development of a framework of experience with the aim of informing analysis and design of interactive mediated environments (IME) to induce/evoke stimulating experience in users and to encourage them in 'staying there'. Informed from filmmaking, three levels of experience are explored: voyeuristic (i.e. 'joy of seeing the new and the wonderful'), visceral (i.e. thrill of spectacle and attractions) and vicarious (i.e. transfer of emotion through another person, being or object). With varying degrees of emphasis, story is experienced by spectators through one or a combination of these three to provide meaning.

- by Tim Marsh
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- Virtual Reality, Virtual Environment, Design of experiment, Information Analysis

There has been a significant body of work in recent years in the development of e-learning tools and products. The main focus has been on models that are developed from the constructivist tradition, based on the notion that learners... more

- by Lachlan Mackinnon
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- Educational Technology, Computer Science Education, Art, Lifelong Learning

The paper discusses the use of immersive virtual reality systems for the cognitive rehabilitation of dysexecutive syndrome, usually caused by prefrontal brain injuries. With respect to classical P&P and flat-screen computer rehabilitative tools, IVR systems might prove capable of evoking a more intense and compelling sense of presence, thanks to the highly naturalistic subject-environment interaction allowed. Within a constructivist framework applied to holistic rehabilitation, we suggest that this difference might enhance the ecological validity of cognitive training, partly overcoming the implicit limits of a lab setting, which seem to affect non-immersive procedures especially when applied to dysexecutive symptoms. We tested presence in a pilot study applied to a new VR-based rehabilitation tool for executive functions, V-Store; it allows patients to explore a virtual environment where they solve six series of tasks, ordered for complexity and designed to stimulate executive functions, programming, categorical abstraction, short-term memory and attention. We compared sense of presence experienced by unskilled normal subjects, randomly assigned to immersive or non-immersive (flat screen) sessions of V-Store, through four different indexes: self-report questionnaire, psychophysiological (GSR, skin conductance), neuropsychological (incidental recall memory test related to auditory information coming from the "real" environment) and count of breaks in presence (BIPs). Preliminary results show in the immersive group a significantly higher GSR response during tasks; neuropsychological data (fewer recalled elements from "reality") and less BIPs only show a congruent but yet non-significant advantage for the immersive condition; no differences were evident from the self-report questionnaire. A larger experimental group is currently under examination to evaluate significance of these data, which also might prove interesting with respect to the question of objective-subjective measures of presence.

- by Gianluca Castelnuovo
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- Information Systems, Psychology, Cognitive Science, Cyberpsychology

This work contributes an integrated and flexible approach to sign language processing in virtual environments that allows for interactive experimental evaluations with high ecological validity. Initial steps deal with real-time tracking and processing of manual gestures. Motion data is stereoscopically rendered in immersive virtual environments with varying spatial and representational configurations. Besides flexibility, the most important aspect is the seamless integration within a VR-based neuropsychological experiment software. Ongoing studies facilitated with this system contribute to the understanding of the cognition of sign language. The system is beneficial for experimenters because of the controlled and immersive three-dimensional environment enabling experiments with visual depth perception that can not be achieved with video presentations.

- by Isa Werth
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- Computer Science, Sign Language, Virtual Reality (Computer Graphics), Sign Languages

The MOVES Institute's mission is research, application, and education in the grand challenges of modeling, virtual environments, and simulation. Specialties are 3D visual simulation, networked virtual environments, computergenerated autonomy, human-performance engineering, immersive technologies, defense /entertainment collaboration, and evolving operational modeling.

This paper summarizes ongoing research aimed at developing knowledge and tools required to implement automated robotic crane erection processes in construction. In the proposed approach, construction cranes are treated as multi-degree-of-freedom robots and modeled in a virtual environment. The virtual cranes are then provided with motion planning algorithms that enable them to find collision-free and time-efficient paths for each piece that needs to be erected. Inverse kinematics then determines the crane motions required to move elements in previously computed paths. The virtual crane model provides realistic visualizations of erection processes and detailed erection schedules. An effective method to coordinate the motions of multiple cranes on larger construction sites is also developed.

- by Eduardo Miranda
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- Motion Planning, Virtual Environment, Inverse Kinematics, Design for Manufacture

Extruded shapes and patterns are widely used by graphic designers to increase the visual richness and realism of 3D models and virtual environments in general. However, the traditional approach that uses polygonal mesh is inappropriate for real-time rendering, in which, just a limited number of graphic primitives can be processed. Hence the interest of using per-pixel approaches. In this paper, we introduce a new imagebased technique for rendering extruded details and shapes. We use a single RGBA texture in which we store a binary shape, its Euclidean Distance Transform (EDT), and the two components of the EDT gradient. The rendering algorithm is based on a raytracing like procedure, performed in texture space. The use of the EDT allows skipping empty space and thus, minimizes the number of ray-tracing steps. Per-pixel extrusion mapping produces very convincing results, and runs at interactive frame rates.

- by Abderrahim Saaidi
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- Graphic Design, Real-time rendering, Virtual Environment, Ray Tracing

Virtual reality (VR) can induce postural instability in standing and walking, as quantified with kinematic parameters. This study examines the effect of a VR environment on kinetic gait parameters. Ten healthy volunteers walked on an instrumented treadmill in a VR environment and a non-VR environment. In the VR environment, a corridor with colored vertical stripes comprising the walls was projected onto a concave screen placed in front of the treadmill. The speed of the moving image was perceptually equivalent to the speed of the treadmill, creating an illusion that subjects walked through the corridor. Vertical ground reaction forces were sampled. Kinetic parameters that reflect gait stability (weight acceptance peak force, weight acceptance rate, push-off peak force and push-off rate) were compared between the VR and non-VR environments. Subjects walked in the VR environment with increased magnitudes and rates of weight acceptance force and with increased rates of push-off force. Variability in weight acceptance rates and peak forces, and variability in push-off peak forces, were also increased in the VR environment. The gait deviations reflect a compensatory response to visual stimulation that occurs in the VR environment, suggesting that walking in a VR environment may induce gait instability in healthy subjects.

- by Kenton Kaufman
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- Mechanical Engineering, Kinetics, Visual perception, Motion perception

Interactive navigable 3D visualisations of built and natural environments have become commonplace in design and planning of urban environments and landscapes, and are regarded as potent prototyping and communication tools. In training applications, for instance for fire fighters, virtual environments displayed on desktop monitors or on projection screens are used to represent situations and scenarios that cannot be created in

- by J. Houtkamp
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- Mental Representation, Virtual Environment, Text, Urban Environment

Background: Binge eating behavior constitutes a central feature of both bulimia nervosa (BN) and binge eating disorder (BED). Cue exposure therapy (CET) has been proposed as an effective intervention. Objective: To determine which situations and specific cues trigger higher levels of binge craving and to use the results in the development of virtual reality scenarios in which CET could be applied with BN and BED patients. Method: Participants were 101 outpatients, 50 with BED and 51 with BN, according to DSM-5 criteria, and 63 healthy undergraduate students who completed a self-administered questionnaire to assess binge craving. Results: The likelihood of binge craving in the clinical group was greater when alone at home, during the afternoon/early evening and in the late evening/at night, at weekends, and at dinner time or between meals. Higher levels of craving were produced in the kitchen, bedroom, dining room, and bakery situations. With regard to the specific cues reported, the presence of and access to high calorie food and snacks was the most commonly reported cue. Although some gender differences regarding triggering factors were obtained, no statistical differences were observed between ED subtypes. BN and BED patients showed significantly higher levels of binge craving than controls in all the contexts except when feeling positive affect; in this situation, levels of craving were low in both groups. Conclusions: This information regarding trigger contexts and specific cues can be used to create valid and reliable virtual environments for CET. Indeed, the data from this study may serve to develop a wide range of situations with different levels of binge craving, in which the therapeutic aim is to extinguish conditioned responses and facilitate the generalization of craving extinction.

- by Irene Pericot-Valverde and +2
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- Information Systems, Psychology, Cognitive Science, Food

Computer-based training (CBT) has become an important training tool and is used e!ectively in providing part-task activities. In the military domain virtual environments (VEs) have long been exploited, mainly through virtual reality (VR), to create realistic working environments. More recently, augmented reality (AR) and advanced embedded training (AET) concepts have also emerged and the development of &&AR-AET'' and &&VR-CBT'' concepts promise to become essential tools within military training. Whilst the advantages of both AR and VR are attractive, the challenges for delivering such applications are, generally, technology led. Equally as important, however, is the incorporation of human factors design and implementation techniques and this has been recognized by the development and publication of International Standard ISO 13407, Human-Centred Design Processes for Interactive Systems. Examples described in this paper serve to review Human Factors issues associated with the use of both AR and VR training systems. Whilst there are common issues between AR and VR applications in considering the potential of synthetic training environments, it is also necessary to address particular human-centred design issues within each application domain.

- by Alex Stedmon
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- Human Factors, Augmented Reality, Work Environment, Virtual Reality

This paper proposes a new preprocessing method for interactive rendering of complex polygonal virtual environments. The approach divides the space that observer can reach into many rectangular viewpoint regions. For each region, an outer rectangular volume(ORV) is established to surround it. By adaptively partitioning the boundary of the ORV together with the viewpoint region, all the rays that originate from the viewpoint region are divided into the beams whose potentially visible polygon number is less than a preset threshold. If a resultant beam is the smallest and intersects many potentially visible polygons, the beam is simplified as a fixed number of rays and the averaged color of the hit polygons is recorded. For other beams, their potentially visible sets (PVS) of polygons are stored respectively. During an interactive walkthrough, the visual information related to the current viewpoint is retrieved from the storage. The view volume clipping, visibility culling and detail simplification are efficiently supported by these stored data. The rendering time is independent of the scene complexity.

- by Qunsheng Peng and +1
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- Virtual Environment, Volume Rendering