A comparison of guidance cues in desktop virtual environments

Designers of educational and entertainment desktop virtual environments (VEs) have employed a variety of cues for motivating users to perform actions or adopt particular viewpoints. However, there has been little formal study comparing user responses to such cues. This paper reports the results of a preliminary study of five cues (agents, signs, man-made landmarks, environmental landmarks, and trails) for motivating actions in virtual environments. Given a sample task of navigating to a target destination, no significant differences between the cues were observed in terms of overall success or speed. However, significant differences between the cues were found on other measures, including minimization of detours (trails) and awareness of guidance (agents, signs, trails). Frequency of desktop VE usage was also found to influence performance.     

A sense of self: The role of presence in virtual environments

Several factors contribute to an individual’s experiences in computer-based environments. Previous research shows one such factor, the degree to which users feel connected to a virtual environment, influences the actions of individuals within the environment ( and ). Additional factors, such as people’s personality and the personality of their avatar, influence behaviors in virtual environments (McCreery, Krach, Schrader, & Boone, 2012). The current study focused on the role of presence as it affects behavior within the virtual environment. Presence has been defined as the psychological state where virtual experiences feel authentic. However, the degree to which presence acts as a mediating variable in virtual environments is not well understood. The current study employed a combination of survey instruments and direct observation to explore the relationships among personality of self and avatar, presence, and behaviors within a virtual environment. Findings indicated that participant scores in the domain of agreeableness were a significant predictor of agreeable behavior in the virtual environment. However, with the exception of negative effects (e.g., dizziness), presence does not appear to influence behavior. Overall implications for these findings are discussed.     

The role of presence in the level of anxiety experienced in clinical virtual environments

Recent reviews point towards that Virtual Reality Exposure Therapy (VRET) can be an effective medium to provide exposure therapy for anxiety disorders. The concept of presence, usually defined as the sense of being inside the virtual environment, has been considered the principal mechanism that leads to the experience of anxiety in clinical virtual environments. The present study sought to examine the relationship between sense of presence and in-session anxiety in a sample of 210 students showing high and low test anxiety when exposed to both clinical and non-stressful virtual environments. This is the largest study conducted to date with the aim of examining the relationship between presence and anxiety in clinical virtual environments, and the first to explore separately the relationship between presence and state-anxiety in phobic and non-phobic participants. The results suggest that presence was not related to anxiety in a non-stressful environment. It was also found that although presence is related to anxiety in both groups of students when exposed to clinical virtual environments, this relationship was clearly stronger for high test anxiety students. This line of research will broaden our understanding of the mechanisms that lead to the efficacy of VRET.     

The influence of the availability of visual cues on the accurate perception of spatial dimensions in architectural virtual environments

Several authors have observed that spatial dimensions tend to be underestimated in virtual environments. In this study, we hypothesize that the availability of visual cues in virtual environments has an influence on the accuracy of perception. An experiment was conducted to compare spatial perception in real and virtual environments that were modeled differently and visualized using a head-mounted display. Results suggest that the greater the availability of visual cues, the greater the level of accuracy in the estimates, especially for egocentric dimensions (p < 0.001). In the end, this study contributes to a better understanding of how architectural virtual environments should be modeled for use in professional or commercial applications where accurate and reliable simulations are required.     

Cubic-Mouse-based interaction in virtual environments

Recently prop-based interfaces in combination with two-handed interaction techniques have become increasingly popular. Passive real-world props augment interaction through tactile feedback and often lead to more intuitive interaction. The Cubic Mouse is a new, 3D input device based on the prop idea. It consists of a cube-shaped box with three perpendicular rods passing through its center. We use a six-degrees-of-freedom (6-DOF) tracker embedded in the Cubic Mouse to track the device's position and orientation. The rods can be pushed and pulled, allowing the constrained input of three degrees of freedom. The 6-DOF Cubic Mouse, also allows rotation of the rods, which adds another three DOF. Altogether, we have a total of 12 analog degrees of freedom available with the Cubic Mouse, six DOF through the tracking and another six through the rods. In addition, the Cubic Mouse has application-programmable control buttons. We present a variety of interaction techniques developed around the Cubic Mouse, which we have implemented in various application prototypes. Our geo-scientific visualization system allows the exploration of data from the oil and gas industry in local and distributed virtual environments. With our automotive partners, we're developing a system for steering and visualizing crash simulations. Other application areas include medical visualization and terrain visualization     

Collaborative configuration in virtual environments

Most collaborative work in virtual environments involves creating and changing objects according to some rules which correspond to what is known as configuration tasks in the field of knowledge based systems. Also, tasks such as presenting information as 3D objects in a virtual environment or dynamically changing (reconfiguring) embodiments to adapt to an environment are configuration tasks. These tasks can be supported by a generic tool, a configuration engine. However collaborative configuration requires a high level of interactivity to be meaningful which hence must be supported by the engine. We are, therefore, utilising our previous experiences in developing configuration engines to develop one, 3dObelics, that is suited for the highly interactive tasks of collaborative configuration in virtual environments. The engine is built on the idea of viewing configuration as a pure constraint satisfaction problem and that a well-defined modelling language can overcome the difficulties that are associated with constraint programming. 3dObelics uses DIVE, a tool kit for building collaborative virtual environments, and a system for speech control of agents in DIVE labelled Talking Agents. 3dObelics is meant to act as a platform for building multi-user configuration applications with a minimum of programming. To our knowledge, 3dObelics is the first general tool for this.     

High-level interpretation in virtual environments

As virtual environments applications become more complex, there is a need to interpret user interaction in terms of high-level concepts. In this paper, the relations between conceptual representations of actions and their physical simulation in virtual worlds is investigated. A model inspired fromnatural language processing (NLP) research in the linguistic interpretation of dynamic scenes has been developed. The experiments are based on real-time animation software, which has been enhanced with a symbolic information processing layer, originally developed for NLP-based animation. We report the implementation of a high-level interpretation module that is able to recognize complex actions fromlow-level physical events in the virtual world and discuss its performance as well as directions for further developments.     

The design space of dynamic interactive virtual environments

Virtual environments have become a key component of many fields and the critical component of virtual reality applications. Due to their virtual nature, they can accommodate an infinite number of possibilities. A theoretical work is presented, which decomposes those innumerous possibilities into concepts to help clarify the vast design space and provide insights into future applied research. We propose that what makes environments interesting and engaging is having worlds that are both active and reactive. This article explores the manifestations of those actions and reactions in what we term: dynamic components and interactions. We term worlds containing these dynamic interactive virtual environments (DIVE). An analysis of each component time was performed, with the purpose of providing a theoretical understanding of the respective design spaces. Initially, we collected the myriad possibilities of each component, e.g., the possible kinds of interactions. We point to examples throughout the field to ground and explain concepts presented. We then categorized of each area into taxonomies. The result of the analyses provides insights into the design space of virtual environments, exposes several avenues of research that are yet underexplored, and provides better understandings of ways in which DIVE creation can be supported.     

Storytelling in virtual environments from a virtual guide perspective

This paper describes our proposal for storytelling in virtual environments from a virtual guide perspective, detailing the involved knowledge representation and algorithms. In our model the guide begins at a particular location and starts to navigate the world telling the user stories related to the places she visits. Our guide tries to emulate a real guides behaviour in such a situation. In particular, she behaves as a spontaneous real guide who knows stories about the places in the virtual world but has not prepared an exhaustive tour nor a storyline.     

Update rates and fidelity in virtual environments

Interaction is the primary characteristic of a Virtual Environment and update rate is normally taken as an index or measure of the interactivity of the system. The speed of many systems is dictated by the slowest component which is often the Computer Image Generator (CIG). It is common for the workload of the CIG to vary and hence the performance of the system. This paper shows how a variable update rate can produce undesirable results. Two solutions to this problem are presented: service degradation and worst-case. In the case of the CIG, service degradation would require the quality of the image to be reduced such that the time taken never exceeds a given deadline. The worst-case technique works by finding the longest time taken to render any view and then uses that as the deadline for completion. The support of predictive methods is one of several benefits of this approach. An implementation of the worst-case technique is described which takes finer control over the CIG than usual and may be applied to many existing systems with little modification.     

Height effects in real and virtual environments

The study compared human perceptions of height, danger, and anxiety, as well as skin conductance and heart rate responses and postural instability effects, in real and virtual height environments. The 24 participants (12 men, 12 women), whose average age was 23.6 years, performed lean-over-the-railing and standing tasks on real and comparable virtual balconies, using a surround-screen virtual reality (SSVR) system. The results indicate that the virtual display of elevation provided realistic perceptual experience and induced some physiological responses and postural instability effects comparable to those found in a real environment. It appears that a simulation of elevated work environment in a SSVR system, although with reduced visual fidelity, is a valid tool for safety research. Potential applications of this study include the design of virtual environments that will help in safe evaluation of human performance at elevation, identification of risk factors leading to fall incidents, and assessment of new fall prevention strategies.     

Creation and control of rain in virtual environments

Realistic outdoor scenarios often include rain and other atmospheric phenomena, which are difficult to simulate in real time. In the field of real-time applications, a number of solutions have been proposed which offer realistic but costly rain systems. Our proposal consists in developing a solution to facilitate the creation and control of rain scenes and to improve on previously used methods while offering a realistic appearance of rain. Firstly, we create and define the areas in which it is raining. Secondly, we perform a suitable management of the particle systems inside them. We include multiresolution techniques in order to adapt the number of particles, their location and their size according to the view conditions. Furthermore, in this work the physical properties of rain are analyzed and its features are incorporated into the final approach that we propose. The presented method is completely integrated in the GPU. We offer a solution which is fast, simple, efficient and easily integrated into existing virtual-reality environments.     

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.     

Collaborative learning in multi-user virtual environments

Multi-user virtual environments (MUVEs) have captured the attention and interest of educators as remote collaborative learning environments due to their immersion, interaction and communication capabilities. However, productive learning interactions cannot be considered a given and careful consideration of the design of learning activities and organizational support must be provided to foster collaboration. In this paper, a model to support collaborative learning in MUVEs is presented. This model enables the scaffolding of learning workflows and organizes collaborative learning activities by regulating interactions. Software architecture is developed to support the model, and to deploy and enact collaborative learning modules. A user-centered design has been followed to identify successful strategies for modeling collaborative learning activities in a case study. The results show how interactions with elements of 3D virtual worlds can enforce collaboration in MUVEs.     

Character emotion experience in virtual environments

The present paper presents an emotion module from an authoring tool of interactive storytelling being developed within the European Project—INSCAPE. The Atmosphere Editor (AE) is an INSCAPE software plug-in. Its aim is to help authors to easily create virtual interactive scenes that are recognized as emotional in order to contribute to higher coherence of their content and simultaneously to emphasize their communication purposes. It works through the attribution of emotional meaning to virtual environments and characters classes that act on the virtual story-world. Therefore, it is designed to produce a semantic intervention in the story but does not intend to transcend the storyteller work. AE presents then a taxonomy capable of sustaining the communicational optimization of the interactive narratives at an emotional level. The AE intervention develops in addition a possible pedagogical virtue permitting the learning by the story authors about potential emotional uses of specific virtual parameters. It permits also the INSCAPE user to understand the emotional semantics canons of the interactive virtual stories.

Advanced interaction techniques in virtual environments

Fundamental to much of the Virtual Reality work is, in addition to high-level 3D graphical and multimedia scenes, research on advanced methods of interaction. The “visitor” of such virtual worlds must be able to act and behave intuitively, as he would in everyday situations, as well as receive expectable natural behaviour presented as feedback from the objects in the environment, in a way that he/she has the feeling of direct interaction with his/her application. In this paper we present several techniques to enrich the naturalness and enhance the user involvement in the virtual environment. We present how the user is enabled to grab objects without using any specific and elaborate hand gesture, which is more intuitive and close to the way humans are used to do. We also introduce a technique that makes it possible for the user to surround objects without any force-feedback interaction device. This technique allows the user to surround or “walk” with the virtual hand on the object's surface and look for the best position to grab it.     

The movement patterns and the experiential components of virtual environments

Human movement in virtual environments (VEs) is a largely unstudied area, and there are no well-established methods of measuring it in VEs. Consequently, it is unclear how movement affects the experiential side of VEs. We introduce a novel method of measuring and modelling human movement. A specific information entropy-based modelling method enabled us to identify different movement patterns and analyse the experiential components related to them. The data was collected by registering the movement patterns of 68 participants who were in a virtual house doing a search task. The experiential side of the VE was measured with the Experimental Virtual Environment Questionnaire (EVEQ). Four movement patterns were identified. In addition, fluent movement in VEs was related to a high sense of presence. Moreover, the participants who moved fluently in the environment assessed their skills high. The results show how movement is related the way in which people experience the VE. The movement analysis method introduced here is applicable to other related research areas as well.     

Navigation in hypertext through virtual environments

Users of hypertext systems require some form of navigation aid or 'browser'. Typically these have been produced as schematic representations of the hypertext network. The advent of 'virtual reality' technology, and particularly less costly forms of this, offers new possibilities for hypertext navigation whereby information can be presented in the form of a virtual environment. Users can then move around the virtual world in much the same conceptual fashion as they move around the real world. Based upon an extensive review of hypertext navigation problems and the aiding systems proposed to deal with these, four different types of navigation aid have been built; these are schematic and spatial representations in two and three dimensions. Of particular interest is the 3D spatial representation, built as a virtual environment in Virtus Walkthrough; the proposition is that such a virtual world navigation aid will offer substantial usability advantages for hypertext databases.     

Providing force feedback in virtual environments

An integral part of successfully manipulating objects is the sensation of touch or force. Experiments with telerobots (robots controlled at a distance) show that the sensation of force and contact improves the efficiency and accuracy of such tasks. Many believe that the same can be said of tasks in a virtual environment. Unfortunately, it is not possible to actually grasp a virtual object in the same manner as you would a real object because virtual objects are defined in the computer, while the user exists in the real world. Thus, there must be some intermediate device that provides the user with the effects of touch, either through the virtual environment itself or in a physical model of the object, which then communicates information to the virtual environment and displays the virtual object to the user. At the University of Tokyo, we are experimenting with surface display, a method that allows users to directly manipulate an object in a virtual environment by touching a physical model of the object's surface as presented by an intermediate device outside the computer. We have created a prototype of such a device that measures the force exerted on the surface. We have also implemented control and calculation methods, and have evaluated both the device and the methods in experiments with users. These experiments have validated the concepts underlying our work, and we are continuing to investigate implementation issues