Virtual interpersonal touch: Haptic interaction and copresence in collaborative virtual environments

As digital communication becomes more commonplace and sensory rich, understanding the manner in which people interact with one another is crucial. In the current study, we examined the manners in which people touch digital representations of people, and compared those behaviors to the manner in which they touch digital representations of nonhuman objects. Results demonstrated that people used less force when touching people than other nonhuman objects, and that people touched the face with less force than the torso area. Finally, male digital representations were touched with more force than female representations by subjects of both genders. We discuss the implications of these data to the development of haptic communication systems as well as for a methodology of measuring the amount of copresence in virtual environments.

Nonverbal communication interface for collaborative virtual environments

Nonverbal communication is an important aspect of real-life face-to-face interaction and one of the most efficient ways to convey emotions, therefore users should be provided the means to replicate it in the virtual world. Because articulated embodiments are well suited to provide body communication in virtual environments, this paper first reviews some of the advantages and disadvantages of complex embodiments. After a brief introduction to nonverbal communication theories, we present our solution, taking into account the practical limitations of input devices and social science aspects. We introduce our sample of actions and implementation using our VLNET (Virtual Life Network) networked virtual environment and discuss the results of an informal evaluation experiment.     

Analyzing place metaphors in 3D educational collaborative virtual environments

In the recent years, the usage of three dimensional (3D) collaborative virtual environments (CVEs) for educational purposes has increased. The metaphors behind the design of virtual places are quite diverse, from replication of real universities to art museums and scientific labs. This paper reports the results of a case study where the students of our university, as a part of their course assignment, analyzed place metaphors used in a range of 3D educational CVEs vs. the corresponding educational goals. The students suggested a design for a virtual campus representing the Norwegian University of Science and Technology (NTNU). The results of this study provide some suggestions concerning the characterization of different design features in educational CVEs and the suitability of such features for different educational goals. Also, a preliminary set of design guidelines for an ideal virtual campus representing a real university is presented. Finally, some challenges associated with using 3D CVEs in various educational situations are discussed.     

Evaluating the effects of frame of reference on spatial collaboration using desktop collaborative virtual environments

Spatial collaboration is an everyday activity in which people work together to solve a spatial problem. For example, a group of people will often arrange furniture together or exchange directions with one another. Collaborative virtual environments using desktop PCs are particularly useful for spatial activities when the participants are distributed. This work investigates ways to enhance distributed, collaborative spatial activities. This paper explores how different frames of reference affect spatial collaboration. Specifically, it reports on an experiment that examines different combinations of exocentric and egocentric frames of reference with two users. Tasks involve manipulating an object, where one participant knows the objective (director) and the other performs the interactions (actor). It discusses the advantages and disadvantages of the different combinations for a spatial collaboration task. Findings from this study demonstrate that frames of reference affect collaboration in a variety of ways and simple exocentric-egocentric combinations do not always provide the most usable solution.     

Coordination components for collaborative virtual environments

This paper deals with the behavior of virtual environments from the collaboration point-of-view, in which actors (human or virtual beings) interact and collaborate by means of interdependent tasks. In this sense, actors may realize tasks that are dependent on tasks performed by other actors, while the interdependencies between tasks (through resource management and temporal relations) delineate the overall behavior of a virtual environment. Our main goal is to propose an approach for the coordination of those behaviors. Initially a generic study of possible interdependencies between collaborative tasks is presented, followed by the formal modeling (using Petri Nets) of coordination mechanisms for those dependencies. In order to implement such mechanisms, an architecture of reusable and pluggable coordination components is also introduced. These components are used in an implementation of a multi-user videogame. The presented approach is a concrete step to create virtual societies of actors that collaborate to reach common goals without the risk of getting involved in conflicting or repetitive tasks.     

Avatar gender and personal space invasion anxiety level in desktop collaborative virtual environments

We report an investigation exploring the effect of avatar gender on the anxiety level caused by personal space (PS) invasion in desktop collaborative virtual environments (DCVE). We outline an experiment in which participants, of both genders, whose avatars PS were invaded by other avatars of either gender, reported their anxiety levels through the use of a post-experiment questionnaire. The data from the questionnaire are analysed and discussed. The results suggest that the combination of the gender of the invading avatar and the avatar being invaded has an influence on the PS invasion anxiety level and that the ranking of gender combination groups has a striking difference from those observed for PS invasion in physical environments. Results also show that the participants in general did not register high anxiety, contrary to what one might expect from personal space invasion in the physical world.

基于集合论思想的协同虚拟环境交互研究

交互技术是协同虚拟环境中实现用户间的多感知（视觉、听觉、触觉等）交流与协作的重要手段。目前,在协同虚拟环境中,由于对存在的交互种类缺乏系统、全面的研究方法,从而用户交互程度明显不足,严重影响了地理协同工作。将集合论思想引入到协同虚拟环境的交互中,首次系统、完备性地分析了协同虚拟环境中存在的交互类型,将复杂的交互研究简化为6类交互的组合。在此基础上,采用Agent技术构建了智能语义物体模型以辅助交互的实现,并应用VTK和Cal3D软件开发包,实现了协同虚拟环境中基于化身的多种交互。     

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.     

Mediating the expression of emotion in educational collaborative virtual environments: an experimental study

The use of avatars with emotionally expressive faces is potentially highly beneficial to communication in collaborative virtual environments (CVEs), especially when used in a distance learning context. However, little is known about how, or indeed whether, emotions can effectively be transmitted through the medium of a CVE. Given this, an avatar head model with limited but human-like expressive abilities was built, designed to enrich CVE communication. Based on the facial action coding system (FACS), the head was designed to express, in a readily recognisable manner, the six universal emotions. An experiment was conducted to investigate the efficacy of the model. Results indicate that the approach of applying the FACS model to virtual face representations is not guaranteed to work for all expressions of a particular emotion category. However, given appropriate use of the model, emotions can effectively be visualised with a limited number of facial features. A set of exemplar facial expressions is presented.     

An efficient hybrid multicast transport protocol for collaborative virtual environment with networked haptic

In recent years, we have witnessed a growing interest in the synchronous collaboration based class of applications. Several techniques for collaborative virtual environments (CVE), haptic, audio and visual environments (C-HAVE) have been designed. However, several challenging issues remain to be resolved before CVE and C-HAVE become a common place. In this paper, we focus on applications that are based on closely coupled and highly synchronized haptic tasks that require a high-level of coordination among the participants. Four main protocols have been designed to resolve the synchronization issues in such environments: the synchronous collaboration transport protocol, the selective reliable transmission protocol, the reliable multicast transport protocol and the scalable reliable multicast. While these four protocols have shown good performance for CVE and C-HAVE class of applications, none of these protocols has been able to meet all of the basic CVE requirements, i.e., scalability, reliability, synchronization, and minimum delay. In this paper, we present a hybrid protocol that is able to satisfy all of the CVE and C-HAVE requirements and discuss its implementation and results in two tele-surgery applications. This work is partially supported by Grants from Canada Research Chair Program, NSERC, OIT/Ontario Distinguished Researcher Award, Early Research Award and ORNEC Research Grant.     

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.     

An orientation update message filtering algorithm in collaborative virtual environments

Orientation update message filtering is an important issue in collaborative virtual environments (CVEs). Dead-reckoning (DR) is a known effective mechanism for update message filtering. Yet, previous deadreckoning techniques mainly focus on the update message filtering for positions. The existing orientation deadreckoning algorithms are based on fixed threshold values. The drawbacks of fixed thresholding for orientations (FTO) are discussed in this paper. We propose a variable thresholding for orientations (VTO) based on average recent angular velocity. The main advantage of the proposed VTO is the ability of balancing the number of state update messages and shift frequency of direction and speed of rotation.     

Collaborative virtual geographic environments: A case study of air pollution simulation

The integration of high dimensional geo-visualization, geo-data management, geo-process modeling and computation, geospatial analysis, and geo-collaboration is a trend in GIScience. The technical platform that matches the trend forms a new framework unlike that of GIS and is conceptualized in this paper as a collaborative virtual geographic environment (CVGE). This paper focuses on two key issues. One is scientific research on CVGE including the concept definition and the conceptual and system framework development. The other is a prototype system development according to CVGE frameworks for air pollution simulation in the Pearl River Delta. The prototype system integrates air pollution source data, air pollution dispersion models, air pollution distribution/dispersion visualization in geographically referenced environments, geospatial analysis, and geo-collaboration. Using the prototype system, participants from geographically distributed locations can join in the shared virtual geographic environment to conduct collaborative simulation of air pollution dispersion. The collaborations supporting this simulation happen on air pollution source editing, air pollution dispersion modeling, geo-visualization of the output of the modeling, and geo-analysis.     

A framework using cluster-based hybrid network architecture for collaborative virtual surgery

Research on collaborative virtual environments (CVEs) opens the opportunity for simulating the cooperative work in surgical operations. It is however a challenging task to implement a high performance collaborative surgical simulation system because of the difficulty in maintaining state consistency with minimum network latencies, especially when sophisticated deformable models and haptics are involved. In this paper, an integrated framework using cluster-based hybrid network architecture is proposed to support collaborative virtual surgery. Multicast transmission is employed to transmit updated information among participants in order to reduce network latencies, while system consistency is maintained by an administrative server. Reliable multicast is implemented using distributed message acknowledgment based on cluster cooperation and sliding window technique. The robustness of the framework is guaranteed by the failure detection chain which enables smooth transition when participants join and leave the collaboration, including normal and involuntary leaving. Communication overhead is further reduced by implementing a number of management approaches such as computational policies and collaborative mechanisms. The feasibility of the proposed framework is demonstrated by successfully extending an existing standalone orthopedic surgery trainer into a collaborative simulation system. A series of experiments have been conducted to evaluate the system performance. The results demonstrate that the proposed framework is capable of supporting collaborative surgical simulation.     

The design and realization of CoViD: a system for collaborative virtual 3D design

Many important decisions in the design process are made during fairly early on, after designers have presented initial concepts. In many domains, these concepts are already realized as 3D digital models. Then, in a meeting, the stakeholders for the project get together and evaluate these potential solutions. Frequently, the participants in this meeting want to interactively modify the proposed 3D designs to explore the design space better. Today’s systems and tools do not support this, as computer systems typically support only a single user and computer-aided design tools require significant training. This paper presents the design of a new system to facilitate a collaborative 3D design process. First, we discuss a set of guidelines which have been introduced by others and that are relevant to collaborative 3D design systems. Then, we introduce the new system, which consists of two main parts. The first part is an easy-to-use conceptual 3D design tool that can be used productively even by naive users. The tool provides novel interaction techniques that support important properties of conceptual design. The user interface is non-obtrusive, easy-to-learn, and supports rapid creation and modification of 3D models. The second part is a novel infrastructure for collaborative work, which offers an interactive table and several large interactive displays in a semi-immersive setup. It is designed to support multiple users working together. This infrastructure also includes novel pointing devices that work both as a stylus and a remote pointing device. The combination of the (modified) design tool with the collaborative infrastructure forms a new platform for collaborative virtual 3D design. Then, we present an evaluation of the system against the guidelines for collaborative 3D design. Finally, we present results of a preliminary user study, which asked naive users to collaborate in a 3D design task on the new system.     

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.     

Cross‐platform management of intelligent objects behaviors in serious virtual environments

In this paper, we present a generic interaction framework that controls intelligent objects' actions in different virtual world (VW) platforms. These actions are based on the state of external platform‐independent artificial intelligence‐based systems such as multi‐agent and rule‐based systems. We have evaluated the proposed framework by means of two intelligent objects, a door and a noticeboard, incorporating them in Second Life and OpenWonderland VWs. These objects allow to work along three advanced aspects of a serious virtual environment: it is a dynamic space where participants are synchronously informed about activities evolution inside the virtual space, it can integrate processes and information coming from the real world, and it needs norms to organize participants actions, to define actions consequences, and to prevent undesired participants behaviors. Copyright © 2011 John Wiley & Sons, Ltd.     

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.