Context-driven interaction in immersive virtual environments

There are many interaction tasks a user may wish to accomplish in an immersive virtual environment. A careful examination of these tasks reveals that they are often performed under different contexts. For each task and context, specialized interaction techniques can be developed. We present the context-driven interaction model: a design pattern that represents contextual information as a first-class, quantifiable component within a user interface and supports the development of context-sensitive applications by decoupling context recognition, context representation, and interaction technique development. As a primary contribution, this model provides an enumeration of important representations of contextual information gathered from across the literature and describes how these representations can effect the selection of an appropriate interaction technique. We also identify how several popular 3D interaction techniques adhere to this design pattern and describe how the pattern itself can lead to a more focused development of effective interfaces. We have constructed a formalized programming toolkit and runtime system that serves as a reference implementation of the context-driven model and a discussion is provided explaining how the toolkit can be used to implement a collection of representative 3D interaction interfaces.     

Using immersive virtual environments for certification

As virtual environments move from research laboratories to commercial use, there is a need to define the appropriate role of VEs in certifying the systems they simulate. This article describes the unique features of this developing technology, as well some key issues to consider when using VEs for certification     

Visualization of CFD results in immersive virtual environments

An object-oriented event-driven immersive virtual environment (VE) is described for the visualization of computational fluid dynamics (CFD) results. The VE incorporates the following types of primitive software objects: interface objects, support objects, geometric entities, and finite elements. The fluid domain is discretized using either a multi-block structured grid or an unstructured finite element mesh. The VE allows natural ‘fly-through’ visualization of the model, the CFD grid, and the model's surroundings. In order to help visualize the flow and its effects on the model, the VE incorporates the following objects: stream objects (lines, surface-restricted lines, ribbons, and volumes); colored surfaces; elevation surfaces; surface arrows; global and local iso-surfaces; vortex cores; and separation/attachment surfaces and lines. Most of these objects can be used for dynamically probing the flow. Particles and arrow animations can be displayed on top of stream objects. Primitive response quantities as well as derived quantities can be used. A recursive tree search algorithm is used for real-time point and value search in the CFD grid.     

2D human-computer interaction techniques in immersive virtual environments

Menus and dialog boxes are useful enhancements for the direct manipulation based interaction style of Virtual Environments. In this paper an implementation of 2D HCI techniques in immersive Virtual Environments is discussed. The applicability of 2D techniques for interaction with the environment is illustrated in the case of a BOOM for immersive viewing. A Pinch Glove is used as the input device to interact with the menus and dialog boxes. A programming approach to make Motif based interfacing widgets suitable for stereoscopic display is discussed. Some examples demonstrate the use of 2D HCI techniques in immersive Virtual Environments.     

Comparing methods for numerical input in immersive virtual environments

Virtual Reality - Numeric input is a sub-case of alphanumeric input where a user wishes to communicate a numerical value to the computer. While this is a straightforward task for windows-based...     

Redirecting walking and driving for natural navigation in immersive virtual environments

Walking is the most natural form of locomotion for humans, and real walking interfaces have demonstrated their benefits for several navigation tasks. With recently proposed redirection techniques it becomes possible to overcome space limitations as imposed by tracking sensors or laboratory setups, and, theoretically, it is now possible to walk through arbitrarily large virtual environments. However, walking as sole locomotion technique has drawbacks, in particular, for long distances, such that even in the real world we tend to support walking with passive or active transportation for longer-distance travel. In this article we show that concepts from the field of redirected walking can be applied to movements with transportation devices. We conducted psychophysical experiments to determine perceptual detection thresholds for redirected driving, and set these in relation to results from redirected walking. We show that redirected walking-and-driving approaches can easily be realized in immersive virtual reality laboratories, e. g., with electric wheelchairs, and show that such systems can combine advantages of real walking in confined spaces with benefits of using vehicle-based self-motion for longer-distance travel.     

虚拟现实全景流体绘画系统的可用性研究

虚拟现实环境给三维空间场景应用带来更强的真实感和身临其境的体验。在虚拟现实场景中经 常需要使用 360全景图像生成沉浸式环境背景,其中全景流体动力学绘画系统提供了一个新的全景图绘制方 法。在调研虚拟现实技术在流体绘画领域应用的适用性测试中,本文综合运用用户测试法、操作日志分析法、 事后问卷调查法和访谈法,对基于虚拟现实的全景式流体绘画创作系统进行可用性评估,并创意性地使用可视 化方法辅助日志分析。所有的受试者均认为系统的可用性不低于一般水平,利用该系统完成流体绘画的创作工 作不需要受试者具有专业绘画经验。受试者对系统的功能效果持积极肯定的意见,并期待尝试用其他交互形式 代替手柄类交互方式以促进艺术创作的表达。其研究方法和结果将为同类系统的开发和评估提供参考。     

User experimentation: an evaluation of velocity control techniques in immersive virtual environments

While many of the existing velocity control techniques are well designed, the techniques are often application-specific, making it difficult to compare their effectiveness. In this paper, we evaluate five known velocity control techniques using the same experimental settings. We compare the techniques based on the assumption that a good travel technique should be easy to learn and easy to use, should cause the user to have few collisions with the VE, should allow the user to complete tasks faster, and should promote better recollection of the environment afterwards. In our experiments, we ask twenty users to use each velocity control technique to navigate through virtual corridors while performing information-gathering tasks. In all cases, the users use pointing to indicate the direction of travel. We then measure the users’ ability to recollect the information they see in the VE, as well as how much time they spend in the VE and how often they collide with the virtual walls. After each test, we use questionnaires to evaluate the ease of learning and ease of use of the velocity control technique, and the users’ sense of presence in the environment. Each of the travel techniques is then evaluated based on the users’ performances in the VE and the results of their questionnaires.     

Examining the effect of body ownership in immersive virtual and augmented reality environments

The traditional rubber hand illusion is a psychological experiment where participants are under the illusion that a rubber hand is part of their own body. This paper examines the use of real, virtual and augmented reality environments for identifying the elements that influence body ownership in healthy participants. Compared to the classical experiment where a plastic rubber hand was used, a realistic 3D representation was chosen to create the same illusion this time in both immersive virtual reality and augmented reality. Experiments were performed on 30 volunteers undergoing testing session composed of three stages. Participants were asked to complete two different questionnaires, one measuring their cognitive workload and another one regarding their experience with the rubber hand illusion. In addition, EEG signals of the individuals were recorded, resulting in 90 electroencephalogram datasets. Results indicate correlations between ownership statements with beta and gamma electroencephalogram bands in premotor cortex activity. Link between higher gamma production in ventral premotor area during the illusion was established in previous studies.     

A methodology for the evaluation of travel techniques for immersive virtual environments

We present a framework for the analysis and evaluation oftravel, or viewpoint motion control, techniques for use in immersive virtual environments (VEs). In previous work, we presented a taxonomy of travel techniques and a set of experiments mapping parts of the taxonomy to various performance metrics. Since these initial experiments, we have expanded the framework to allow evaluation of not only the effects of different travel techniques, but also the effects of many outside factors simultaneously. Combining this expanded framework with the measurement of multiple response variables epitomises the philosophy oftestbed evaluation. This experimental philosophy leads to a deeper understanding of the interaction and the technique(s) in question, as well as to broadly generalisable results. We also present an example experiment within this expanded framework, which evaluates the user's ability to gather information while travelling through a virtual environment. Results indicate that, of the variables tested, the complexity of the environment is by far the most important factor.     

Towards video-based immersive environments

Video provides a comprehensive visual record of environment activity over time. Thus, video data is an attractive source of information for the creation of virtual worlds which require some real-world fidelity. This paper describes the use of multiple streams of video data for the creation of immersive virtual environments. We outline our multiple perspective interactive video (MPI-Video) architecture which provides the infrastructure for the processing and analysis of multiple streams of video data. Our MPI-Video system performs automated analysis of the raw video and constructs a model of the environment and object activity within this environment. This model provides a comprehensive representation of the world monitored by the cameras which, in turn, can be used in the construction of a virtual world. In addition, using the information produced and maintained by the MPI-Video system, our immersive video system generates virtual video sequences. These are sequences of the dynamic environment from an arbitrary view point generated using the real camera data. Such sequences allow a user to navigate through the environment and provide a sense of immersion in the scene. We discuss results from our MPI-Video prototype, outline algorithms for the construction of virtual views and provide examples of a variety of such immersive video sequences.     

Towards user centred design (UCD) in architecture based on immersive virtual environments

This paper describes a generic concept of how to combine the experience of user centred design (UCD) in the field of Human Computer Interaction (HCI) with the traditional approach of participatory design (PD) in an architectural design process. Even if some basic requirements of this generic method are not available yet, this paper will also describe an approach, which enables planners even now to involve end users by using virtual environments (VE) as immersive and spatial prototype. It will be described and illustrated by the way of example using the building project Centre of Virtual Engineering of the Fraunhofer Institute for Industrial Engineering (IAO) in Stuttgart. It demonstrates that the transfer of the UCD approach to architectural planning combined with the provision of an adequate prototype can make a significant contribution towards an increase in quality and performance in building and construction projects.     

The effect of visual and interaction fidelity on spatial cognition in immersive virtual environments

Accuracy of memory performance per se is an imperfect reflection of the cognitive activity (awareness states) that underlies performance in memory tasks. The aim of this research is to investigate the effect of varied visual and interaction fidelity of immersive virtual environments on memory awareness states. A between groups experiment was carried out to explore the effect of rendering quality on location-based recognition memory for objects and associated states of awareness. The experimental space, consisting of two interconnected rooms, was rendered either flat-shaded or using radiosity rendering. The computer graphics simulations were displayed on a stereo head-tracked head mounted display. Participants completed a recognition memory task after exposure to the experimental space and reported one of four states of awareness following object recognition. These reflected the level of visual mental imagery involved during retrieval, the familiarity of the recollection, and also included guesses. Experimental results revealed variations in the distribution of participants' awareness states across conditions while memory performance failed to reveal any. Interestingly, results revealed a higher proportion of recollections associated with mental imagery in the flat-shaded condition. These findings comply with similar effects revealed in two earlier studies summarized here, which demonstrated that the less "naturalistic" interaction interface or interface of low interaction fidelity provoked a higher proportion of recognitions based on visual mental images.     

Designing presence for real locomotion in immersive virtual environments: an affordance-based experiential approach

This paper describes a framework for designing systems for real locomotion in virtual environments (VEs) in order to achieve an intense sense of presence. The main outcome of the present research is a list of design features that the virtual reality technology should have in order to achieve such a goal. To identify these features, an approach based on the combination of two design strategies was followed. The first was based on the theory of affordances and was utilized to design a generic VE in which the affordances of the corresponding real environment could be evoked. The second was the experiential design applied to VEs and was utilized to create an experience of locomotion corresponding to that achievable in a real environment. These design strategies were chosen because of their potential to enhance the sense of presence. The proposed list of features can be utilized as an instrument that allows VE designers to evaluate the maturity of their systems and to pinpoint directions for future developments. A survey analysis was performed using the proposed framework, which involved three case studies to determine how many features of the proposed framework were present and their status. The result of such analysis represented a measure of the completeness of the systems design, of the affordances provided to the user, and a prediction of the sense of presence.     

The use of ‘exploratory learning’ for supporting immersive learning in virtual environments

User interfaces are becoming more intuitive following the requirements of the individual learner and reinforcing the drive towards more personalised learning and greater learner autonomy. There are clearly a new set of challenges emerging for teaching practitioners that will have implications upon not just what is learned but importantly upon lesson planning. This paper explores these changes to teaching through a consideration of an exploratory learning model which allows practitioners to rethink how they teach in 3D and immersive spaces where learning sequences and experiences are choreographed to support peer interactions and exchanges. The ELM extends from Kolb’s experiential learning model to adapt the use of 3D applications, and provides examples from research and development projects to exemplify how the model works in practice. Teaching in these contexts provides less emphasis upon curriculum and more emphasis upon sequencing learning experiences, meta-reflection, peer assessment and group work.     

Poster3D: a system for three-dimensional authoring and presentation in immersive virtual environments

We developed a simple system for three-dimensional (3D) authoring and presentation in immersive virtual reality environments. Our system enables a user to create and edit content both through direct manipulation using hand gestures in an immersive environment, and by using a 2D GUI on a PC desktop. The system also exploits various features of 3D information visualization to produce effective and interactive presentations. In a system trial, users found that the system enhanced their experience. The system helps users create 3D educational materials more easily and learn through the materials with greater interest and motivation. Noritaka Osawa received his B.S., M.S. and Ph.D. degrees in information science from the University of Tokyo in 1983, 1985, and 1988 respectively. After working for a software company and the University of Electro-communications, he has been at the National Institute of Multimedia Education since 1998. He has also been jointly appointed at the Graduate University for Advanced Studies since 2001. He now works for them as a Professor. His current research interests include human–computer interfaces using virtual reality technologies, information visualization, and system software. Sangtae Kim received B.A. degree in Visual Communication from YougIn University, Korea, in 1996, and M.A. and Ph.D. degrees in Design, from the University of Tsukuba, 2001, and 2004, respectively. He is currently an Assistant Professor of the institute of Art and Design, The University of Tsukuba, Ibaraki, Japan. His research interests include visual communication, dynamic information graphics, multimedia systems, 3DCG, and Web3D technology. He planned for the MDD (Multi-Dynamic Documentation) project in 2003. At present, he is involved in the development of Web3D contents (Interactive Anatomy system) that uses MDD technology.     

Experiencing immersive virtual reality in museums

Virtual Reality (VR) has been regarded as a highly effective technology that enables people to gain enjoyable and immersive information about museum collections. Drawing from the four realms of the experience economy, we assume absorptive experiences influence immersive experiences, overall museum VR tour experience, and intention to visit a museum. The results show that all the hypotheses are supported. Furthermore, we compared and tested the proposed model and its rival model (postulating the direct influence of the four realms of the experience economy on museum VR experience) and found that the proposed model is better than the rival model.     

An experimental investigation of menu selection for immersive virtual environments: fixed versus handheld menus

Virtual Reality - With the development of consumer-grade virtual reality (VR) systems, the interface and interaction design for immersive virtual environments have become a critical issue for VR...     

Autocalibration of multiprojector CAVE-like immersive environments

In this paper, we present the first method for the geometric autocalibration of multiple projectors on a set of CAVE-like immersive display surfaces including truncated domes and 4 or 5-wall CAVEs (three side walls, floor, and/or ceiling). All such surfaces can be categorized as swept surfaces and multiple projectors can be registered on them using a single uncalibrated camera without using any physical markers on the surface. Our method can also handle nonlinear distortion in the projectors, common in compact setups where a short throw lens is mounted on each projector. Further, when the whole swept surface is not visible from a single camera view, we can register the projectors using multiple pan and tilted views of the same camera. Thus, our method scales well with different size and resolution of the display. Since we recover the 3D shape of the display, we can achieve registration that is correct from any arbitrary viewpoint appropriate for head-tracked single-user virtual reality systems. We can also achieve wallpapered registration, more appropriate for multiuser collaborative explorations. Though much more immersive than common surfaces like planes and cylinders, general swept surfaces are used today only for niche display environments. Even the more popular 4 or 5-wall CAVE is treated as a piecewise planar surface for calibration purposes and hence projectors are not allowed to be overlapped across the corners. Our method opens up the possibility of using such swept surfaces to create more immersive VR systems without compromising the simplicity of having a completely automatic calibration technique. Such calibration allows completely arbitrary positioning of the projectors in a 5-wall CAVE, without respecting the corners.