Seamless interaction in virtual reality

Jot is a novel research interface for virtual reality modeling. This system seamlessly integrates and applies a variety of virtual and physical tools, each customized for specific tasks. The Jot interface not only moves smoothly from one tool to another but also physically and cognitively matches individual tools to the tasks they perform. In particular, we exploit the notion that gestural interaction is more direct, in many cases, than traditional widget based interaction. We also respect the time tested observation that some operations-even conceptually three dimensional ones-are better performed with 1D or 2D input devices, whereas other operations are more naturally performed using stereoscopic views, higher DOF input devices, or both. Ultimately we strive for a 3D modeling system with an interface as transparent as the interaction afforded by a pencil and a sheet of paper. For example, the system should facilitate the tasks of drawing and erasing and provide an easy transition between the two. Jot emerged from our previous work on a mouse based system, called Sketch, for gesturally creating imprecise 3D models. Jot extends Sketch's functionality to a wider spectrum of modeling, from concept design to detailed feature based parametric parts. Jot also extends the interaction in Sketch to better support individual modeling tasks. We extended Sketch's gestural framework to integrate interface components ranging from traditional desktop interface widgets to context sensitive gestures to direct manipulation techniques originally designed for immersive VR     

This is NOT a game [virtual reality]

Training exercises with a large degree of realism have always been the goal of the armed forces. To a large extent, the US military has succeeded in creating the training simulations needed to turn out the world's most successful fighting forces, but at a staggering cost. The paper discusses the use of simulation and virtual reality in military training.     

Design and evaluation of a high− fidelity virtual reality manufacturing planning system

Virtual Reality - Manufacturing applications of virtual reality (VR) technology are growing. The challenge is to design, integrate, and evaluate VR simulation for manufacturing Systems that...     

A PC-based distributed multiple display virtual reality system

In this paper, a PC-based distributed multiple-display virtual reality system is constructed. The system is a PC-based CAVE environment. Five PCs are used in this system; one is the master responsible for receiving user's input signals, the others are clients for images rendering. Devices are added to synchronize the RGB signals from client PCs.

A software library is developed to drive the system properly. The software is designed in object-oriented language and flexibility for different interface devices is considered.

With the proposed system, developers can easily elaborate PC-based virtual reality applications and build PC virtual worlds at much lower cost.     

A framework for fidelity evaluation of immersive virtual reality systems

Virtual Reality - Developments in visual and tracking systems have expanded virtual reality (VR) applications and led to VR becoming a powerful tool for decision making, planning, and conducting...     

An objective measure for the visual fidelity of virtual reality and the risks of falls in a virtual environment

Despite decades of development of virtual reality (VR) devices and VR’s recent renaissance, it has been difficult to measure these devices’ effectiveness in immersing the observer. Previously, VR devices have been evaluated using subjective measures of presence, but in this paper, we suggest that postural stability can be used to objectively assess visual fidelity of VR headsets. We validated this measure by testing known differences between the devices. This study also aimed to determine the stability of healthy participants, while in a stable virtual world, compared to eyes-open and eyes-closed conditions and therefore provide a standard of safety requirements for future experimentation. Participants’ ability to maintain a stable centre of pressure was measured using a Wii Balance Board, covered by a foam pad. Stability in eyes-open and eyes-closed conditions was compared with: (1) an iPod Touch in a simple Google cardboard style headset, (2) the Oculus Rift Development Kits (DK) DK1, DK2, with and without the tracking of linear head movements, and (3) the Samsung Gear VR. With a stable VR visual stimulus, the eyes-open condition allowed for significantly greater postural stability than the other conditions, which supports the validity of posturography as a measure of visual fidelity. Further, the iPod Touch, with its narrow field of view and rudimentary software, was significantly less effective at destabilising participants with visual perturbations than the other headsets, with their wider field of view and time warping. Unexpected results are discussed with respect to the possible limitations of the experimental design.     

Evaluating the usability of virtual reality user interfaces

A walkthrough method for evaluating virtual reality (VR) user interfaces is described and illustrated with a usability assessment of a virtual business park application. The method is based on a theory of interaction that extends Norman's model of action. A walkthrough analysis method uses three models derived from the theory. The first model describes goal-oriented task action, the second exploration and navigation in virtual worlds, while the third covers interaction in response to system initiative. Each stage of the model is associated with generic design properties that specify the necessary support from the system for successful interaction. The evaluation method consists of a checklist of questions using the properties and following the model cycle. Use of the method uncovered several usability problems. Approaches to evaluation of VR applications and future work are discussed.     

Evaluating the usability of virtual reality user interfaces

A walkthrough method for evaluating virtual reality (VR) user interfaces is described and illustrated with a usability assessment of a virtual business park application. The method is based on a theory of interaction that extends Norman's model of action. A walkthrough analysis method uses three models derived from the theory. The first model describes goal-oriented task action, the second exploration and navigation in virtual worlds, while the third covers interaction in response to system initiative. Each stage of the model is associated with generic design properties that specify the necessary support from the system for successful interaction. The evaluation method consists of a checklist of questions using the properties and following the model cycle. Use of the method uncovered several usability problems. Approaches to evaluation of VR applications and future work are discussed.     

Towards a customizable immersive virtual reality serious game for earthquake emergency training

Earthquake emergencies require a variety of behavioral responses in order to ensure the safety of occupants, which is different from simply exiting a building in fire emergencies. This makes it more complex to train building occupants in order to acquire skills that align to best practices for immediate earthquake response and post-earthquake evacuation. In recent years, Immersive Virtual Reality (IVR) and Serious Games (SGs) have become popular as training tools for earthquake emergencies. IVR SGs have been introduced to train individuals for specific building layouts or settings with fixed training objectives. However, the lack of flexibility in existing IVR SGs makes it challenging to have widespread uptake as trainees require different training objectives, pedagogical strategies, context, and content. As a result, the effectiveness of IVR SGs training is jeopardized if the customization ability is limited. To overcome this limitation, this paper presents a customization framework for IVR SGs suited to earthquake emergency training, using the concept of adaptive game-based learning. Trainees can receive training in context by customizing virtual environments, storylines, and teaching methods. A case study was undertaken to validate the proposed framework. Results showed the potential to carry out the customization process with ease, to generate a customized training experience, and to deliver the customized training for optimum learning.     

An affordable surround‐screen virtual reality display

Abstract— Building a projection‐based virtual reality display is a time‐, cost‐, and resource‐intensive enterprise, and many details contribute to the final display quality. This is especially true for surround‐ screen displays where most of them are one‐of‐a‐kind systems or custom‐made installations with specialized projectors, framing, and projection screens. In general, the costs of acquiring these types of systems have been in the hundreds and even millions of dollars, specifically for those supporting synchronized stereoscopic projection across multiple screens. Furthermore, the maintenance of such systems adds an additional recurrent cost, which makes them hard to afford for general introduction in a wider range of industry, academic, and research communities. A low‐cost easy‐to‐maintain surround‐screen design based on off‐the‐shelf affordable components for the projection screens, framing, and display systems is presented. The resulting system quality is comparableto significantly more expensive commercially available solutions. Additionally, users with average knowledge can implement this design, and it has the added advantage that single components can be individually upgraded based on necessity as well as available funds.     

Learning game innovations in immersive game environments: a factor analytic study of students’ learning inventory in virtual reality

Virtual Reality - The research is designed to trigger students’ game innovations and facilitate their creative learning process by providing them with a “stimulated” immersive...     

虚拟现实大空间下多虚拟目标被动触觉交互方法

针对虚拟现实（VR）大空间下为重定向行走的用户提供被动触觉时存在的虚实交互目标无法一一对应的问题,提出了一种用两个物理代理作为触觉代理为多个虚拟目标提供触觉反馈的方法,以在基于人工势场（APF）的重定向行走过程中,交替地满足用户被动触觉的需求。针对重定向行走算法本身以及标定不精确等原因造成的虚实不对齐的问题,对虚拟目标的位置及朝向进行设计并且在交互阶段引入触觉重定向。仿真实验表明对虚拟目标位置和朝向的设计可以大幅降低对齐误差;而用户实验结果证明触觉重定向的引入进一步提升了交互准确性,且能为用户带来更丰富、更具沉浸感的体验。     

Personalised e-learning through an educational virtual reality game using Web services

This paper describes how a personalised educational game architecture has been used in conjunction with Web services to provide remote access to the system. The educational game is a virtual reality adventure game that performs affective user modelling by measuring emotional characteristics of users. Virtual reality (VR) games are so popular among children and adolescents that can be used for the purposes of educational software to render it more attractive and motivating. The benefits of such an application can be maximised if it is available over the Web. Software applications that operate over the Web are targeted to a wide range of users. Hence they need a high degree of adaptivity and dynamic individualisation to each user that interacts with the application. This should include the students’ emotional state that affects their learning. However, the environment of a Web-based VR-game that performs user modelling is so demanding that the technology of Web services is necessary for its effective operation and interoperability. Moreover, reusability may be achieved for the user modelling component.

A comparative study using an autostereoscopic display with augmented and virtual reality

Advances in display devices are facilitating the integration of stereoscopic visualisation in our daily lives. However, autostereoscopic visualisation has not been extensively exploited. In this paper, we present a system that combines augmented reality (AR) and autostereoscopic visualisation. We also present the first study that compares different aspects using an autostereoscopic display with AR and virtual reality (VR), in which 39 children from 8 to 10 years old participated. In our study, no statistically significant differences were found between AR and VR. However, the scores were very high in nearly all of the questions, and the children also scored the AR version higher in all cases. Moreover, the children explicitly preferred the AR version (81%). For the AR version, a strong and significant correlation was found between the use of the autostereoscopic screen in games and seeing the virtual object on the marker. For the VR version, two strong and significant correlations were found. The first correlation was between the ease of play and the use of the rotatory controller. The second correlation was between depth perception and the game global score. Therefore, the combinations of AR and VR with autostereoscopic visualisation are possibilities for developing edutainment systems for children.     

Head-mounted display versus desktop for 3D navigation in virtual reality: a user study

Virtual Reality (VR) has been constantly evolving since its early days, and is now a fundamental technology in different application areas. User evaluation is a crucial step in the design and development of VR systems that do respond to users’ needs, as well as for identifying applications that indeed gain from the use of such technology. Yet, there is not much work reported concerning usability evaluation and validation of VR systems, when compared with the traditional desktop setup. The paper presents a user study performed, as a first step, for the evaluation of a low-cost VR system using a Head-Mounted Display (HMD). That system was compared to a traditional desktop setup through an experiment that assessed user performance, when carrying out navigation tasks in a game scenario for a short period. The results show that, although users were generally satisfied with the VR system, and found the HMD interaction intuitive and natural, most performed better with the desktop setup.

Hand-adaptive user interface: improved gestural interaction in virtual reality

Most interactive user interfaces (UIs) for virtual reality (VR) applications are based on the traditional eye-centred UI design principle, which primarily considers the user’s visual searching efficiency and comfort, but the hand operation performance and ergonomics are relatively less considered. As a result, the hand interaction in VR is often criticized as being less efficient and precise. In this paper, the user’s arm movement features, such as the choice of the hand being used and hand interaction position, are hypothesized to influence the interaction results derived from a VR study. To verify this, we conducted a free hand target selection experiment with 24 participants. The results showed that (a) the hand choice had a significant effect on the target selection results: for a left hand interaction, the targets located in spaces to the left were selected more efficiently and accurately than those in spaces to the right; however, in a right hand interaction, the result was reversed, and (b) the free hand interactions at lower positions were more efficient and accurate than those at higher positions. Based on the above findings, this paper proposes a hand-adaptive UI technique to improve free hand interaction performance in VR. A comprehensive comparison between the hand-adaptive UI and traditional eye-centred UI was also conducted. It was shown that the hand-adaptive UI resulted in a higher interaction efficiency and a lower physical exertion and perceived task difficulty than the traditional UI.

     

Personal Varrier: Autostereoscopic virtual reality display for distributed scientific visualization

As scientific data sets increase in size, dimensionality, and complexity, new high resolution, interactive, collaborative networked display systems are required to view them in real-time. Increasingly, the principles of virtual reality (VR) are being applied to modern scientific visualization. One of the tenets of VR is stereoscopic (stereo or 3d) display; however the need to wear stereo glasses or other gear to experience the virtual world is encumbering and hinders other positive aspects of VR such as collaboration. Autostereoscopic (autostereo) displays presented imagery in 3d without the need to wear glasses or other gear, but few qualify as VR displays. The Electronic Visualization Laboratory (EVL) at the University of Illinois at Chicago (UIC) has designed and built a single-screen version of its 35-panel tiled Varrier display, called Personal Varrier. Based on a static parallax barrier and the Varrier computational method, Personal Varrier provides a quality 3d autostereo experience in an economical, compact form factor. The system debuted at iGrid 2005 in San Diego, CA, accompanied by a suite of distributed and local scientific visualization and 3d teleconferencing applications. The CAVEwave National LambdaRail (NLR) network was vital to the success of the stereo teleconferencing.     

Developing speech input for virtual reality applications: A reality based interaction approach

An input device should be natural and convenient for a user to transmit information to a computer, and should be designed from an understanding of the task to be performed and the interrelationship between the task and the device from the perspective of the user. In order to investigate the potential of speech input as a reality based interaction device, this paper presents the findings of a study that investigated speech input in a VR application. Two independent user trials were combined within the same experimental design to evaluate the commands that users employed when they used free speech in which they were not restricted to a specific vocabulary. The study also investigated when participants were told they were either talking to a machine (e.g. a speech recognition system) or instructing another person to complete a VR based task. Previous research has illustrated that when users are limited to a specific vocabulary, this can alter the interaction style employed. The findings from this research illustrate that the interaction style users employ are very different when they are told they are talking to a machine or another person. Using this knowledge, recommendations can be drawn for the development of speech input vocabularies for future VR applications.     

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.     

Reality-based interaction affecting mental workload in virtual reality mental arithmetic training

ABSTRACT

The concept of digital game-based learning (DGBL) evolves rapidly together with technological enhancements of virtual reality (VR) and smart phones. However, the mental workload (MWL) that VR-training applications demand and motivational qualities originating from user experience (UX) should be identified in order to create effective and enjoyable training/learning challenges that fit with individual users’ capabilities. This study examined the effects of reality-based interaction (RBI) and VR on measures of student motivation and MWL, in a mental arithmetic game for secondary school pupils. In a randomised controlled trial with sixty school children, a mental arithmetic game was tested with three different interaction and two different presentation methods – VR RBI, VR head-mounted-display tapping and tablet flick-gesture. Results found a significant effect of RBI on MWL but no differences in enjoyment of training were found between VR-experience and tablet training-experience. In fact, adding the gaming-context to the mental arithmetic task created an enjoyable, motivating experience regardless of presentation or interaction-style.