Depth perception in shuffleboard: Depth cues effect on depth perception in virtual and augmented reality system

The virtual reality (VR) and augmented reality (AR) applications have been widely used in a variety of fields; one of the key requirements in a VR or AR system is to understand how users perceive depth in the virtual environment and AR. Three different graphics depth cues are designed in shuffleboard to explore what kind of graphics depth cues are beneficial for depth perception. We also conduct a depth‐matching experiment to compare performance in VR and AR systems using an optical see‐through head‐mounted display (HMD). The result shows that the absolute error increases as the distance becomes farther. Analysis from the inverse of distance shows that box depth cues have a significant effect on depth perception, while the points depth cues and line depth cues have no significant effect. The error in diopter in AR experiment is lower than that in VR experiment. Participants in the AR experiment under medium illuminance condition have less error than those under low and high illuminance conditions. Men have less error than women in certain display conditions, but the advantage disappears when there is a strong depth cue. Besides, there is no significant effect of completion time on depth perception.     

Virtual and augmented reality for cultural computing and heritage: a case study of virtual exploration of underwater archaeological sites (preprint)

The paper presents different issues dealing with both the preservation of cultural heritage using virtual reality (VR) and augmented reality (AR) technologies in a cultural context. While the VR/AR technologies are mentioned, the attention is paid to the 3D visualization, and 3D interaction modalities illustrated through three different demonstrators: the VR demonstrators (immersive and semi-immersive) and the AR demonstrator including tangible user interfaces. To show the benefits of the VR and AR technologies for studying and preserving cultural heritage, we investigated the visualisation and interaction with reconstructed underwater archaeological sites. The base idea behind using VR and AR techniques is to offer archaeologists and general public new insights on the reconstructed archaeological sites allowing archaeologists to study directly from within the virtual site and allowing the general public to immersively explore a realistic reconstruction of the sites. Both activities are based on the same VR engine, but drastically differ in the way they present information and exploit interaction modalities. The visualisation and interaction techniques developed through these demonstrators are the results of the ongoing dialogue between the archaeological requirements and the technological solutions developed.     

基于增强现实的机器人远程控制系统研究

虚拟现实技术的应用使远程控制系统得到发展,增强现实技术是虚拟现实技术的拓展,它将计算机生成的虚拟物体叠加到用户感知的真实世界中.提出并实现了一种基于增强现实的机器人远程控制系统,并就其结构和关键技术进行详细的说明,实验及运行结果表明该系统能有效地改善人机交互能力,并能提高远程控制的精度.     

Maps and Globes in Virtual Reality

This paper explores different ways to render world‐wide geographic maps in virtual reality (VR). We compare: (a) a 3D exocentric globe, where the user's viewpoint is outside the globe; (b) a flat map (rendered to a plane in VR); (c) an egocentric 3D globe, with the viewpoint inside the globe; and (d) a curved map, created by projecting the map onto a section of a sphere which curves around the user. In all four visualisations the geographic centre can be smoothly adjusted with a standard handheld VR controller and the user, through a head‐tracked headset, can physically move around the visualisation. For distance comparison exocentric globe is more accurate than egocentric globe and flat map. For area comparison more time is required with exocentric and egocentric globes than with flat and curved maps. For direction estimation, the exocentric globe is more accurate and faster than the other visual presentations. Our study participants had a weak preference for the exocentric globe. Generally the curved map had benefits over the flat map. In almost all cases the egocentric globe was found to be the least effective visualisation. Overall, our results provide support for the use of exocentric globes for geographic visualisation in mixed‐reality.     

Intelligent virtual environments for virtual reality art

The development of virtual reality (VR) art installations is faced with considerable difficulties, especially when one wishes to explore complex notions related to user interaction. We describe the development of a VR platform, which supports the development of such installations, from an art+science perspective. The system is based on a CAVE™-like immersive display using a game engine to support visualisation and interaction, which has been adapted for stereoscopic visualisation and real-time tracking. In addition, some architectural elements of game engines, such as their reliance on event-based systems have been used to support the principled definition of alternative laws of Physics. We illustrate this research through the development of a fully implemented artistic brief that explores the notion of causality in a virtual environment. After describing the hardware architecture supporting immersive visualisation we show how causality can be redefined using artificial intelligence technologies inspired from action representation in planning and how this symbolic definition of behaviour can support new forms of user experience in VR.     

Evaluation of quality and personalisation of VR/AR/MR learning systems

ABSTRACT

The paper aims to analyse the problem of quality evaluation and personalisation of virtual reality/augmented reality/mixed reality (VR/AR/MR). First of all, systematic review of relevant scientific literature on the research topic was conducted. After that, findings of the systematic review concerning evaluation of quality and personalisation of VR/AR/MR learning environments are presented. The author’s VR/AR/MR learning systems/environments quality evaluation and personalisation framework is also presented in the paper. Evaluation of quality of VR/AR/MR platforms/environments should be based on (a) applying both expert-centred (top-down) and user-centred (bottom-up) quality evaluation methods and (b) separating ‘internal quality’ criteria, and ‘quality in use’ criteria in the set of quality criteria (model). Personalisation of VR/AR/MR platforms/environments should be based on learners’ models/profiles using students’ learning styles, intelligent technologies, and Semantic Web applications.     

A method to measure the uniformity of the virtual image distance in an augmented reality or virtual reality device

The virtual image distance in an augmented reality (AR) or virtual reality (VR) device is an important factor in determining its performance. In this paper, a method for measuring the virtual image distance and its uniformity is proposed. The setup for measurement consists of a two-dimensional spatial sensor array on the translational stage and a pinhole array plate placed in front of the AR or VR device. As the distance between the pinhole plate and the two-dimensional spatial sensor array were changed, the positions of the rays through each pinhole were measured by a two-dimensional spatial sensor array. The ray trajectories through each pinhole were obtained by fitting these positions to straight lines. The relative distances between these ray trajectories were calculated with respect to the distance from the pinhole plate. This method is effective for measuring the uniformity, such as the azimuthal dependence of the virtual image distance or the dependence of the virtual image distance on the distance from the optical axis of the VR lens.     

INTERVALES: INTERactive Virtual and Augmented framework for industriaL Environment and Scenarios

One of Industry 4.0’s greatest challenges for companies is the digitization of their processes and the integration of new related technologies such as virtual reality (VR) and augmented reality (AR), which can be used for training purposes, design, or assistance during industrial operations. Moreover, recent results and industrial proofs of concept show that these technologies demonstrate critical advantages in the industry. Nevertheless, the authoring and editing process of virtual and augmented content remains time-consuming, especially in complex industrial scenarios. While the use of interactive virtual environments through virtual and augmented reality presents new possibilities for many domains, a wider adoption of VR/AR is possible only if the authoring process is simplified, allowing for more rapid development and configuration without the need for advanced IT skills. To meet this goal, this study presents a new framework: INTERVALES. First, framework architecture is proposed, along with its different modules; this study then shows that the framework can be updated by not only IT workers, but also other job experts. The UML data model is presented to format and simplify the authoring processes for both VR and AR. This model takes into account virtual and augmented environments, the possible interactions, and ease operations orchestration. Finally, this paper presents the implementation of an industrial use case composed of collaborative robotic (cobotic) and manual assembly workstations in VR and AR based on INTERVALES data.     

虚拟现实近视干预疗法的原理研究与实现方法

本文主要是分析虚拟现实技术对近视治疗的效果,在实验基础上第一次提出了一种全新的近视治疗方法--“虚拟现实近视干预疗法”,即用医学上的双眼合像法结合虚拟现实技术来治疗近视。本文围绕虚拟现实近视干预疗法的原理研究及实现方法进行探讨;分析并阐述了这一医疗方法涉及到的三个理论基础：医学上的双眼合像的理论、非交叉视差形成的沉浸感、根据儿童患者设计的治疗参数;介绍了虚拟现实近视干预疗法的实现方法。用VisualC＋＋和OpenIn-ventor设计编写了能吸引儿童注意力的用立体眼镜观看的立体显示治疗软件,该软件中的图像具有远近移动、立体显示、人机交互等效果和功能。本文为近视的治疗提供了一个有益的创新,在理论和实践上都是十分有意义的
的。     

Semiotics of virtual reality as a communication process

ABSTRACT

The experience of immersive virtual reality (VR) can be considered as a communication process between human beings, mediated by computer systems, which uses visualisation and other sensory stimulation. In this paper, we analyse how VR characteristics can be explored using semiotic theory and, with methods of generative semiotics, we explore aspects of narrative and interaction in VR. We propose a semiotic analysis of VR communication focusing on syntax, semantics and pragmatics and considering also some principles of generative semiotics. The syntactic level is analysed as determined by the characteristics of the visual communication adopted. The semantic of VR is related to the functional model chosen to realise the virtual system. The pragmatic of VR is based on the human–computer interaction that changes the user's role. We explore how these aspects can be characterised in the context of VR communication design and what principles can be adopted for a VR application, and we present an analysis and a classification of the iconic signs that are being used in VR. Moreover, we present a framework that can be used to classify and describe different kinds of virtual reality systems and to better understand communication in VR, and we use it to classify eight popular systems for e-learning and collaboration.     

增强现实综述

增强现实(augmented reality，AR)技术可以将虚拟的物体合并到现实场景中，并能支持用户与其进行交互，它已经成为虚拟现实研究中的一个重要领域，也是人机界面技术发展的一个重要方向。为了使人们对其有所了解，该文首先概略描述了这个领域的主要研究内容和进展情况，并详细介绍了增强现实中的支撑技术、开发工具和相关理论；然后针对当前AR应用的现状，分析了实现中的难点问题，并给出了与AR普及应用密切相关的一些系统框架和开发平台的描述，最后介绍了几个典型的AR应用实例。     

应用于增强/ 虚拟现实中的模型简化

随着计算机图形学的发展,应用于增强/虚拟现实的模型日趋复杂.为了更好地展示出模型的细节同时保证帧率,需要强大的硬件设备或者低复杂度的模型.实际应用中往往选择后者,降低模型的精细度来保障增强/虚拟现实的实时性成了一个挑战.文章提出了基于贪心算法和拉普拉斯平滑处理的模型简化和优化方法.实验结果表明,在简化相同百分比时,这种方法失真度更小,可以更好地满足增强/虚拟现实设备的实时性.     

How virtual reality affects perceived learning effectiveness: a task–technology fit perspective

The application of virtual reality (VR) in improving users’ learning outcomes, especially in perceived learning effectiveness, is a new area. VR provides visualisation and interaction within a virtual world that closely resembles a real world, bringing an immersive study experience. It also has two special features: representational fidelity and immediacy of control. However, only when the technology fits the tasks that users are performing will it be adopted. In addition, technology itself cannot improve learning outcomes; certain learning behaviours, such as reflective thinking, should be prompted first so that learning outcomes can be improved. The research hypotheses derived from this model have empirically been validated using the responses to a survey among 180 users. These responses have been examined through SmartPLS 2.0. Surprisingly, task–technology fit does not moderate the relationship between VR and technology quality and the relationship between VR and technology accessibility. From this study, we can conclude that VR will influence reflective thinking and further indirectly improve perceived learning effectiveness.     

Vision‐tangible interactive display method for mixed and virtual reality: Toward the human‐centered editable reality

Building a human‐centered editable world can be fully realized in a virtual environment. Both mixed reality (MR) and virtual reality (VR) are feasible solutions to support the attribute of edition. Based on the current development of MR and VR, we present the vision‐tangible interactive display method and its implementation in both MR and VR. We address the issue of MR and VR together because they are similar regarding the proposed method. The editable mixed and virtual reality system is useful for studies, which exploit it as a platform. In this paper, we construct a virtual reality environment based on the Oculus Rift, and an MR system based on a binocular optical see‐through head‐mounted display. In the MR system about manipulating the Rubik's cube, and the VR system about deforming the virtual objects, the proposed vision‐tangible interactive display method is utilized to provide users with a more immersive environment. Experimental results indicate that the vision‐tangible interactive display method can improve the user experience and can be a promising way to make the virtual environment better.     

Effects of postural stability,active control,exposure duration and repeated exposures on HMD induced cybersickness

Cybersickness is common during head-mounted display (HMD) based virtual reality. This study examined whether it is possible to: (1) identify people who are more susceptible to this cybersickness; and (2) find general ways to reduce its occurrence and severity. Our participants were exposed to HMD-based virtual reality four times over two different days (using “Freedom Locomotion VR”). During these 10-min trials, participants were either free-standing or posturally restrained as they actively controlled or passively viewed their locomotion through the virtual environment. Cybersickness was found to increase steadily over time during each exposure. While this cybersickness was markedly reduced on day 2 (compared to day 1), it was not significantly altered by either the use of postural restraints or active locomotion control. However, the sick and well participants in our study were found to differ in terms of their spontaneous postural activity (before they entered virtual reality). We found that the participants who experienced stronger vection also tended to report more severe cybersickness in this study. These findings suggest that we should be able to identify people who are more susceptible to cybersickness and help them become more resistant to it (via repeated exposures to HMD-based virtual reality).     

虚拟现实前沿技术在青少年科普教育中的创新与实践

近年来随着计算机图形技术的发展,越来越多的虚拟现实技术被运用到科普领域,其技术核心就是使用计算机模拟虚拟的情景并通过VR设备来体验。其中效果最好、沉浸性最强的设备非VR头戴式头盔莫属。但是在青少年科普活动中,特别是6-12年龄段的青少年群体,传统的VR头戴式头盔存在着一些明显的安全隐患,就连头盔设备官网都会提示12岁以下儿童不适用于该设备。在此前提下,本文研究混合现实技术和全息投影技术在青少年科普教育中的创新和实践。     

Binocular mobile augmented reality based on stereo camera tracking

Mobile augmented reality (AR) applications have become feasible with the evolution of mobile hardware. For example, the advent of the smartphone allowed implementing real-time mobile AR, which triggered the release of various applications. Recently, rapid development of display technology, especially for stereoscopic displays, has encouraged researches to implement more immersive and realistic AR. In this paper, we present a framework of binocular augmented reality based on stereo camera tracking. Our framework was implemented on a smartphone and supports autostereoscopic display and video see-through display in which a smartphone can be docked. We modified edge-based 3-D object tracking in order to estimate poses of left and right cameras jointly; this guarantees consistent registration across left and right views. Then, virtual contents were overlaid onto camera images using estimated poses, and the augmented stereo images were distorted to be shown through a video see-through display. The feasibility of the proposed framework is shown by experiments and demonstrations.     

Autostereoscopic augmented reality visualization for depth perception in endoscopic surgery

Augmented reality (AR) has received increasing attention in minimally invasive surgery (MIS) applications. The goal of applying AR techniques to MIS is to enhance a surgeon's perception of the spatial relationship by overlaying invisible structures (e.g. tumor or vessels) onto the in vivo endoscopic video acquired during the surgery. One of primary issues of AR visualization is to provide correct depth perception for visible and invisible structures. In this paper, we present a video-based AR system consisting of functional modules for real-time 3D surface capture, reconstruction, and registration with pre-operative segmented CT model. The real-time 3D registration allows precise overlay of invisible structures onto 2D video for AR visualization. The AR overlay result is displayed on a multi-view autostereoscopic lenticular LCD. To study and compare the efficacy of AR visualization techniques, we investigated five different AR visualization modes. Both simulated and in vivo experiments were carried out and autostereoscopic AR visualization results were given. Evaluation and comparison for depth perception between five AR visualization modes are presented. Finally, we conclude the characteristics of these visualization modes. The novelty of our work lies in successful implementation of an end-to-end 3D autostereoscopic AR system from real-time reconstruction and registration with our multi-channel 3D endoscope, and systematic evaluation and comparison of five different visualization modes for depth perception.     

Experimental research into human cognitive processing in an augmented reality environment for embedded training systems

Research into human factors issues associated with the use of augmented reality (AR) technology is very limited. Consequently, there is a need for formal human factors design guidelines to underpin the integration of AR into systems. The Defence Evaluation and Research Agency (DERA) Centre for Human Sciences (CHS) is evaluating the potential of AR for providing real-time training feedback in future advanced embedded training systems for the military. In order to understand the important human factors issues of augmented reality, DERA funded the Advanced VR Research Centre (AVRRC) at Loughborough University to investigate the cognitive ergonomics of this technology. An important aspect of this research is concerned with identifying any human information processing issues that may arise when information is presented via AR and overlaid upon one or more primary display surfaces such as a visual display unit (VDU). Two main issues are addressed in this research. First, the impact of AR on human information processing and second, subjective workload experienced when displaying information via the AR medium. The experiments reported in this paper assess issues of reaccommodation and reaction times to alarms on different display formats. They demonstrate also that AR performs as well as standard display formats.     

Do virtual worlds create better real worlds?

Over the last years, virtual reality (VR) has been said to offer promise for design visualisation and has started to be included in participatory design methodology. This research provides an overview of the use of VR in architectural design and organizational space design, and explores how this application can be integrated with participatory design. The effects of the proposed integration of participatory design, VR, architecture and organization were studied in two pharmaceutical case studies. It was assessed whether the participants actually changed the design and to what extent this affected staff satisfaction and construction costs. The results show that the design was changed, staff satisfaction improved, and costs were reduced.