Extending the desktop workplace by a portable virtual reality system

Users are increasingly recognizing the potential of virtual reality (VR) technology for applications such as data analysis, design review, product development, production planning, marketing, training, etc. The currently established workflow is to design and construct at a desktop system with CAD or modeling software, and visualize and evaluate the results at one or more VR centers equipped with CAVEs or Powerwalls.Discussions with users of VR installations have shown that there is a demand for smaller and more cost efficient VR installations. We have proposed the concept of a small VR system, PI-casso, based on user requirements, guidelines for office workplaces and some end-user tests which showed important limitations and the ergonomics problems of current VR installations. PI-casso is a compact, fully immersive VR system which complements the classic desktop workplace.In this paper we describe a set of user requirements and the results of the design in forming end-user tests, in addition to the concept and the technical specifications of the newly developed system. The first prototype of PI-casso was demonstrated at HCII 2003, where specialists from the human factors/ergonomics and the VR communities used our system and provided suggestions for improvement. This expert feedback was used to develop the improved versions described in this paper.     

环境贴图在VR系统中的应用研究

为了把环境贴图应用于VR系统中，实现场景对象的真实感绘制，首先从分析球面调和函数入手，提出了漫反射环境纹理图的快速计算方法。在研究镜面反射模型时，提出采用箱式滤波器代替Phong余弦函数滤波的方法，从而简化了镜面反射环境纹理图的滤波计算。在实现阶段，采用立方体环境纹理图表示场景光照环境，并对纹理图进行分级细化从而提高了绘制效率。实验表明，该方法实现了物体漫反射和镜面反射的快速绘制，非常适合虚拟现实应用。     

A geoscience perspective on immersive 3D gridded data visualization

We describe visualization software, Visualizer, that was developed specifically for interactive, visual exploration in immersive virtual reality (VR) environments. Visualizer uses carefully optimized algorithms and data structures to support the high frame rates required for immersion and the real-time feedback required for interactivity. As an application developed for VR from the ground up, Visualizer realizes benefits that usually cannot be achieved by software initially developed for the desktop and later ported to VR. However, Visualizer can also be used on desktop systems (unix/linux-based operating systems including Mac OS X) with a similar level of real-time interactivity, bridging the “software gap” between desktop and VR that has been an obstacle for the adoption of VR methods in the Geosciences. While many of the capabilities of Visualizer are already available in other software packages used in a desktop environment, the features that distinguish Visualizer are: (1) Visualizer can be used in any VR environment including the desktop, GeoWall, or CAVE, (2) in non-desktop environments the user interacts with the data set directly using a wand or other input devices instead of working indirectly via dialog boxes or text input, (3) on the desktop, Visualizer provides real-time interaction with very large data sets that cannot easily be viewed or manipulated in other software packages. Three case studies are presented that illustrate the direct scientific benefits realized by analyzing data or simulation results with Visualizer in a VR environment. We also address some of the main obstacles to widespread use of VR environments in scientific research with a user study that shows Visualizer is easy to learn and to use in a VR environment and can be as effective on desktop systems as native desktop applications.     

基于图像绘制的虚拟环境构建与漫游技术研究

虚拟现实是一个重要目标是用计算机构建逼真的视觉世界,使参与者漫游虚拟世界。传统上,其实现是用3D图形学进行几何建模和绘制,但有诸多不足,而基于图像绘制的实现虚拟实现系统的新方法,它克服了3D图形方法的缺点,本文提出了一个实现基于图像绘制的虚拟环境的构建与漫游系统框架模型。     

虚拟教学环境中基于草图的自适应用户界面研究

将草图技术、自适应技术与传统的虚拟现实技术相结合应用于虚拟教学过程中,通过增强用户和系统之间个性化需求的交互处理来提高系统的智能性和友好性,进而有效提高虚拟教学环境的应用效果.旨在虚拟环境中构建基于草图的自适应用户界面并应用于虚拟教学来满足特定教学需求,着重结合实例分析了基于自适应草图用户界面的虚拟教学环境中的草图上下文处理机制.在上述研究基础上,设计开发了一个虚拟教学原型系统,实验证明该系统在用户体验上有明显的改善.     

Integrated manufacture: A role for virtual reality?

Virtual Reality (VR) is fast becoming an affordable technology with potentially wide-ranging applications in many professions including education, medicine and industry. Its advantages over existing technology are primarily that users can visualise, feel involvement and interact with virtual representations of real world activities in real time.

A recently completed study, funded by the EPSRC, examined the feasibility of VR as a tool for UK manufacturing industry. Of primary interest was whether manufacturers perceive a use for VR in their inudstry and, if so, what impact they envisage it will have within their company. A national survey was distributed to over 2,000 UK manufacturing companies randomly selected and interviews carried out with existing users of VR technology. A brief summary of these results is presented.

A demonstration application was developed in desktop VR representing the manufacture of a consumer product in which various stages of the manufacturing process were featured including initial design, manufacture, and testing. The demonstration application is described in detail and user assessments are presented. On the basis of these findings, the potential future role of VR in integrated manufacture is discussed. Relevance to industry

In only a short time, virtual environments have become a focus of serious consideration as a tool for manufacturing and other industry. In order that VR has greatest industrial utility we need to examine and develop its potential as a specialism-free integrating medium within a simultaneous engineering approach.     

大场景虚拟仿真平台设计与实现

简要介绍了基于实景三维地理信息技术及虚拟现实技术,利用通用三维渲染引擎实现的大场景虚拟仿真平台,重点探讨海量数据管理、多层地形渲染等大场景虚拟仿真的关键技术,并利用该平台实现了消防模拟演练及会商决策平台的原型。     

Effects of virtual presence and learning outcome using low-end virtual reality systems

Low-cost technology is essential to integrate Virtual Reality (VR) into educative institutions around the world. However, low-cost technology usually refers to low-end technology, which may compromise the level of immersion of the VR system. This study evaluates whether low-end and high-end VR systems achieve a comparable learning outcome regardless their immersion level. We also analyze the relationship between virtual presence and the learning outcome arising from a VR educational experience. An evaluation with 42 participants was conducted. We measured learning outcome and virtual presence under three different configurations, namely: a desktop computer, a low-end VR system, and a high-end VR system. The impact of simulator sickness was also analyzed. Results revealed a lower learning outcome in the less immersive configuration (i.e. desktop) and a similar learning outcome in both low-end and high-end VR systems. Even though low-end VR systems are less immersive and produce a lower level of virtual presence than high-end VR systems, the results support the use of low-end VR systems for educative applications.     

Synchronization between audiovisual and haptic feeling for constructing edutainment systems

Virtual reality (VR) technology has become more and more mature over the last decade. Development of a virtual environment for training purpose is considered to be one of the most practical applications of the VR technology. Since the VR technology involves all kinds of sensors in exchanging information between the real world and the virtual environment, it is computationally intensive in terms of data processing at an individual sensor and information integration among all the sensors. In general, the information integration has to be well synchronized in order to meet the training needs. At the same time, real-time processing capability is also considered to be critical. Many more practical issues could be uncovered only when a virtual training environment is actually being developed. Based on this belief, this study experiments on the development of a virtual environment for training billiards players. The technical difficulties encountered and the corresponding resolutions are considered beneficial to the development of other practical virtual training environments. This paper summarizes the design and implementation details about our experimental virtual training environment for edutainment systems such as virtual billiard game, virtual air hockey game and virtual drum performance with the algorithms for the synchronization of the information from different sources.     

Robot-enabled tangible virtual assembly with coordinated midair object placement

The assembly in Virtual Reality (VR) enables users to fit virtual parts into existing 3D models immersively. However, users cannot physically feel the haptic feedback when connecting the parts with the virtual model. This work presents a robot-enabled tangible interface that dynamically moves a physical structure with a robotic arm to provide physical feedback for holding a handheld proxy in VR. This enables the system to provide force feedback during virtual assembly. The cooperation between the physical support and the handheld proxy produces realistic physical force feedback, providing a tangible experience for various virtual parts in virtual assembly scenarios. We developed a prototype system that allowed the operator to place a virtual part onto other models in VR by placing the proxy onto the matched structure attached to a robotic arm. We conducted a user evaluation to explore user performance and system usability in a virtual assembly task. The results indicated that the robot-enabled tangible support increased the task completion time but significantly improved the system usability and sense of presence with a more realistic haptic experience.     

虚拟现实手部康复训练系统的设计与实现

将虚拟现实技术应用到康复医学领域,可有效克服传统康复训练方法的局限性,实现安全、舒适和主动的康复训 练。本文设计并实现了一套虚拟现实手部康复训练系统,系统由交互设备、人机交互软件和虚拟环境三部分组成。交互 设备采用 5DT 公司生产的 5DT Data Glove 14 Ultra 数据手套,而人机交互软件运用 Visual Studio 2012 作为开发工具,基于 MFC 编写,实现了用户管理、数据采集、手势信号分类、实时手势识别测试等功能。构建的虚拟场景使用 Flash 游戏, 通过 MFC 和 Flash 游戏之间通讯使用者能使用手势信号实现游戏操控。本文的实验结果表明：虚拟现实手部康复训练系 统能够指导使用者进行有效的手部康复训练,Flash 康复训练游戏能有效提高使用者进行康复训练的积极性和主动性。     

A hardware-independent virtual reality development system

Simulating virtual reality (VR) hardware allows programs to be written in a desktop environment without constant use of limited VR resources. Rather than shifting constantly between VR and workstation environments, developers at the Electronic Visualization Laboratory (EVL) wanted to be able to test VR applications on the normal workstation console. We therefore created a software simulator for VR development. It simulates various VR system features with an interface that runs on an ordinary workstation. The simulator is implemented as part of the CAVE library, the programming library originally written to support the CAVE hardware. It can, however, be used to develop applications for several VR systems, including ImmersaDesks and head-coupled displays. The library itself has been designed so that use of the simulator or any supported hardware is entirely transparent to application code     

基于虚拟现实技术的运动辅助训练系统设计

为了提高教练的指导效率和丰富羽毛球教学与训练的方法,基于虚拟现实技术和KINECT,开发了一套羽毛球辅助训练系统。该系统利用虚拟现实技术,通过3DS MAX工具进行训练场地的虚拟化建模,搭配Cry Engine引擎技术渲染训练场地场景。KINECT被用来识别这些动作以及使用者的位置变化,并将识别结果通过蓝牙模块传输至VR眼镜内,使VR眼镜内的虚拟环境做出图像、声音等相应的改变,以实现虚拟环境下的人机互动。测试表明,本系统能够准确地实现训练场景的虚拟化,对使用者的各个动作的识别率较高,提高了训练者的学习效率。     

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.     

Context analysis to support development of virtual reality applications

To develop a usable Virtual Reality system, the prospective context of use of such a system may need to be considered in order to make sure it meets the requirements and restrictions of that context. In this paper, a contextual analysis is described for a virtual reality system to aid medical diagnosis and treatment planning of vascular disorders. Semi-structured interviews were coupled with observations in an ethnographic approach to requirements gathering in the daily work environment of (interventional) radiologists and vascular surgeons. The identified potential usability problems of a fully immersive prototype, coupled with the needs, requirements and real-life environment of the end-users lead to guidelines for the development of a VR application on a semi-immersive desktop environment. The findings lead us to believe that contextual analysis can be a powerful way to inform the design of a VR application by offering an understanding of the context of use and to inform developers of the most appropriate degree of immersiveness of the VR environment.     

Haptic rendering for dental training system

Immersion and interaction are two key features of virtual reality systems, which are especially important for medical applications. Based on the requirement of motor skill training in dental surgery, haptic rendering method based on triangle model is investigated in this paper. Multi-rate haptic rendering architecture is proposed to solve the contradiction between fidelity and efficiency requirements. Realtime collision detection algorithm based on spatial partition and time coherence is utilized to enable fast contact determination. Proxy-based collision response algorithm is proposed to compute surface contact point. Cutting force model based on piecewise contact transition model is proposed for dental drilling simulation during tooth preparation. Velocity-driven levels of detail haptic rendering algorithm is proposed to maintain high update rate for complex scenes with a large number of triangles. Hapticvisual collocated dental training prototype is established using half-mirror solution. Typical dental operations have been realized including dental caries exploration, detection of boundary within dental cross-section plane, and dental drilling during tooth preparation. The haptic rendering method is a fundamental technology to improve immersion and interaction of virtual reality training systems, which is useful not only in dental training, but also in other surgical training systems. Supported by National Natural Science Foundation of China (Grant Nos. 60605027, 50575011), National High-Tech Research & Development Program of China (Grant No. 2007AA01Z310)     

交互分析模型在协作虚拟环境中实现动态兴趣管理

目前，许多传统的协作式虚拟环境应用主要采用Grid和Locale概念来实现虚拟环境中用户的兴趣管理．但是，当其应用在基于虚拟人的社交性协作仿真时，这些基于位置的兴趣管理方法具有一定的局限性．针对社交性协作仿真这一类虚拟环境应用，提出一种新的在协作虚拟环境中采用动态交互分析的兴趣管理模型．首先定义了兴趣网络和兴趣矩阵的概念；然后描述了交互分析方法，通过该方法来实时分析虚拟人的兴趣焦点；最后在该模型的基础上实现了一个原型虚拟环境系统，并演示了该模型在优化场景绘制和协同感知上的作用．     

Stroke-based modeling and haptic skill display for Chinese calligraphy simulation system

The goal of this paper is to study haptic skill representation and display in a Chinese calligraphy training system. The challenge is to model haptic skill during the writing of different strokes in Chinese characters and to achieve haptic rendering with high fidelity and stability. The planning of the writing process is organized at three levels: task, representation and device level to describe the haptic handwriting skill. State transition graph (STG) is proposed to describe switches between tasks during the handwriting. Chinese characters are modeled using 39 typical strokes, which are further grouped into basic and compound strokes. The compound stroke is considered to be sequential combination of the basic strokes. Straight and curve strokes are modeled using line segment and the Bezier curve, respectively. Information from STG is used for real-time collision detection and haptic rendering. Ambiguity of the collision detection at stroke-corner points is prevented using active stroke combined with local nearest point computation. A modified virtual fixture method is developed for haptic rendering. The approach is tested on a prototype training system using Phantom desktop. Initial experiments suggest that the proposed modeling and rendering method is effective.     

Tele-immersive product evaluation: a review and an implementation framework

A novel virtual tele-immersive product evaluation environment is conceived. The components for the tele-immersive virtual environment for product evaluation include a robust virtual reality (VR) hardware system, associated VR driving software, development tool for the tele-immersive virtual environment, networking software, user representation scheme and tools for developing 3D models and incorporating dynamic properties into the models. We have developed a model to allow users to collaboratively evaluate products using the CAVE^TM, Performer, CAVERN, CAVEActors, Pro/ENGINEER, and ADAMS.