甘南藏区远程教育虚拟教学平台建设

研究和探索了远程教育和虚拟技术相结合的优势和关键问题,针对甘南藏区远程教育发展的现状与需求,分析研究了建设甘南藏区远程教育虚拟教学平台的关键技术和系统的框架结构。     

A survey on virtual reality

Virtual reality (VR) is a scientific method and technology created during the exploration of the nature by human beings to understand, simulate, and better adapt and use the nature. Based on the analysis on the whole process of VR, this paper presents different categories of VR problems and a type of theoretical expression, and abstracts three kinds of scientific and technical problems in VR field. On the basis of foresaid content, this paper also studies current major research objectives, research results and development trend of VR in the aspects of VR modeling method, VR representation technology, human-machine interaction and devices, VR development suites and supporting infrastructure, as well as VR applications. Finally, several theoretical and technical problems that need to be further studied and solved are addressed. Supported by the National Basic Research Program of China (Grant No. 2009CB320805), the National Natural Science Foundation of China (Grant Nos. 60533070, 60503066), and the National High-Tech Research & Development Program of China (Grant Nos. 2006AA01Z333, 2006AA01Z311)     

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.     

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.     

虚拟现实教学手段在煤矿特种工培训中的应用

分析了目前煤矿特种工安全培训质量差的2个主要原因,指出培训手段的落后是导致煤矿特种工培训效果不佳的主要原因;分析了用传统虚拟现实技术开发的培训教学软件的缺陷,介绍了基于三维地理信息系统的虚拟现实技术开发平台的特点;分析了基于3DGIS虚拟现实特种工培训软件的优势。该虚拟现实教学手段为改善煤矿特种工安全培训质量提供了新思路。     

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.     

Transfer of training from virtual reality

This experiment compared the value of real-world training, virtual reality training, and no training in the transfer of learning to the same task performed in real-world conditions. Results provide no evidence of transfer from a virtual reality training environment to a real-world task. There was no significant difference between the virtual reality training group and the group that received no training on the task. The group that received real-world training performed significantly better than both of the other two groups. The results question the utility of virtual training and suggest that in the present configuration, individuals learn performance characteristics specific only to the virtual reality context. Needed improvements to virtual reality for the purpose of enabling the transfer of training are indicated.     

基于增强现实的虚拟城市规划关键技术研究

增强现实是虚拟现实技术的重要分支,已经被成功的应用到众多领域.探讨了增强现实应用于虚拟城市规划的可行性,并给出了一种新颖的基于增强现实技术的城市规划方法.它可以满足城市规划对虚实交互、人机交互的要求,充分体现出增强现实技术在城市规划应用中的优势.介绍了系统结构与工作流程,着重分析了所采用的基于标识的虚实注册方法,并给出了运行结果.     

虚拟现实技术在城市建设中的应用

文章以虚拟现实 ( VR)系统为核心 ,综合利用全数字摄影测量系统、地理信息系统 ( GIS)和网络技术等 ,研究快速建立虚拟城市的技术和方法。通过这个方法 ,将虚拟现实作为一个开放系统和一门实用技术 ,为城市信息化提供一种可交互操作、集成化和人机和谐的方法     

基于虚拟手的人机交互关键技术

基于虚拟手的人机交互技术是虚拟现实中的研究热点。对其中的关键技术进行了研究,采用多边形网格建模方法,建立了虚拟手的逼真几何模型;基于Virtools平台开发了数据手套的数据采集模块,提出使用基于初始值的数据转换方法,解决了开始运动时的跳变问题,同时对手指的外展运动,使用约束值方法进行处理,提高了虚拟手与真实人手匹配一致性;最后,针对虚拟手与虚拟物体的操作交互,提出了一种基于有效阈值角度的抓取算法。通过Virtools平台进行验证,实验结果表明:虚拟手模型逼真度高,手型变化自然;同时实现了虚拟手对虚拟物体的操作交互,具有很强的实用性。     

虚拟工厂现实场景系统平台设计与实现

随着现代化工业不断发展,模拟过程工业真实环境,并在此基础上进行地理信息显示与空间分析等成为当前的研究热点。构建基于虚拟现实(VR)和地理信息系统的(GIS)的虚拟工厂现实场景系统是进行工业生产仿真的一条有效途径,为此,设计开发一个三维的、可维护性强并具有一定扩展性的虚拟工厂现实场景系统具有重要的实用价值。本文通过数据准备、数据生成、系统扩展及客户端设计,实现了虚拟工厂现实场景系统开发过程。通过应用分析与对比,结果表明,该平台化系统具有更高的可扩展性且开发成本低,为虚拟工厂现实场景系统平台设计提供了一个良好的、可扩展的开发途径。     

基于VRML-Java的网络虚拟现实的实现

受到网络速度的限制,传统的网页只能显示文本和图片等二维信息,而网络虚拟现实技术把交互的、逼真的虚拟三维场景引入网络.虚拟现实建模语言（VRML）是一种在互联网上构筑三维虚拟场景的语言标准,通过VRML脚本节点及Java小应用程序实现了用户与虚拟场景更好的交互,并通过Java数据库连接（JDBC）,系统实现了三维场景与二维信息的集成.     

虚拟现实中动画和碰撞的层次细节技术研究及应用

研究了动画和碰撞处理中的层次细节技术，提出了动画层次细节二叉树、碰撞层次细节控制矩阵等多种有效的应用解决方法。实验结果表明这些方法应用在存在大量动画和撞碰处理的虚拟三维场景中有效地提高了渲染实时性。     

虚拟现实中手重映射的偏移检测阈值研究

针对虚拟现实交互（virtual reality interaction,VRI）中环境限制导致使用手的操作效率较低的问题,提出了虚拟现实中手重映射的固定偏移检测阈值估计方法以提高使用手的操作效率,该方法从人的心理感知出发,引入心理测量函数计算出偏移检测阈值从而提升交互体验。首先,根据双选择强制选择（two alternative forced choice,2AFC）理论设计实验,记录被试者使用不同偏移的虚拟手完成目标抓取任务过程中的感觉差异作为评价标准,同时记录被试者完成任务的时间,根据心理测量函数（Quickpsy）对感觉差异进行计算,估计重映射交互的检测阈值;通过协方差确定虚拟手偏移量超过阈值后的方向、幅度和轴向及其相互作用是影响触碰任务性能的显著因素,若在阈值范围内,上述因素就不再影响任务性能;最后,以某VR（virtual reality,虚拟现实）医院物资智能配送系统为例验证所提方法的可行性。研究结果表明,适当的偏移缩短了用户完成触碰任务的时间,能够在提升交互效率的同时降低传统偏移量计算方法对VR的交互保真度的影响。     

基于 BCI 的虚拟现实模拟驾驶教学系统设计

为解决传统模拟驾驶过于强调正常场景的训练,缺少对意外场景下学员心理状态 的监测与协助,且无法反馈和评价驾驶心理状态等问题。以脑机交互(BCI)技术与虚拟现实(VR) 为基础开发 VR 模拟驾驶教学演示系统,利用三维动力学引擎开发了驾驶模拟操作系统,在硬 件上设计可穿戴式脑电波信号检测头盔,基于 BCI 技术实现对学员模拟驾驶大脑状态的监控与 数据评估;有突发模拟事件发生时,系统通过脑机接口技术自动制动或辅助驾驶。在完成模拟 驾驶训练的同时可以根据脑波(EEG)反馈在意外事件中给出紧急解救措施,根据 EEG 情况评估 学员的发挥以及心理素质,为虚拟驾驶等认知负荷较高的教学训练提供了更为丰富与直观沉浸 式交互操作方式,提高了该领域教学训练系统的实用性与可用性。     

基于Leap Motion 的虚拟现实陶艺体验系统

针对陶瓷工艺制作条件严苛导致普及受局限的问题,研发一套基于Leap Motion的虚拟现实陶艺体验系统,使用户得以脱离物理条件限制、以裸手交互的方式,简单直接地进行陶瓷制作工艺体验。在结构方面,将陶器划分为顶部、侧面、底面3 部分,其中侧面结构基于简单均匀广义圆柱体,并利用高斯函数进行形变的约束控制;在交互方面,参考真实陶艺场景,依据陶器结构特性设计用户友好的手势动作和操作范围,并结合动作捕捉和虚拟现实技术,在保证陶器形变可控性的同时,提升系统体验的真实感和沉浸感。设计对比实验和陶器模型偏差值计算方法,量化证明系统可控性和体验的优越性。以沉浸感、完成度、操易度、趣味性4 项作为调查问卷评估指标进行统计分析,验证系统良好的用户体验。     

计算机虚拟现实技术在公路设计中的应用

利用计算机进行交通虚拟现实是当今研究交通问题的一种重要手段。交通虚拟现实技术是在经验研究和数学方法的基础上,利用现代系统工程和计算机虚拟现实技术成果发展起来的新的交通研究方法。由于虚拟现实技术可有效地体现交通系统中交通运行的复杂过程,可按试验要求实现交通状况的再现,大大降低了现场调查的工作量,现己成为分析各种交通流、检验各种拟定交通设施、交通控制方案的有力工具。     

基于Virtools虚拟现实技术的三维解剖图谱开发

解剖图谱在医学教育中一直占据非常重要的地位,然而传统图谱空间信息不足,现有电子图谱图像失真且交互性差。运用虚拟现实技术开发交互性强的三维人体解剖学图谱,首先利用CT设备扫描的真实人体断层数据进行三维重建,获得结构完整的人体局部解剖三维模型;然后基于解剖学知识区分不同结构并利用3DSMAX建立骨骼、血管等独立模型并设置贴图,再导入Virtools中,配以文字、图片等多媒体材料,设置丰富的人机交互手段;最后打包生成可在Windows下直接使用的三维图谱软件。将支持游戏开发的三维引擎用于人体解剖图谱的制作中,强调其交互的丰富性,同时具有真实感强、开发周期短等优点,图谱软件有利于课堂施教和学生自学。     

The impact of computer-mediated immediate feedback on developing oral presentation skills: An exploratory study in virtual reality

Feedback plays a central role in learning. Crucial to this is the nature and timing of the feedback. This experimental study explores the efficacy of immediate computer-mediated feedback within a virtual reality environment designed to facilitate the development of pre-university students' presentation skills. Two conditions were established to assess the efficacy: immediate computer-mediated feedback; a control condition of delayed expert-mediated feedback. Results showed improvement but no statistically relevant difference in performance gains between the two conditions, suggesting both can facilitate learning. Furthermore, students perceived the environment to be an effective and motivating platform in which to practise presentation skills. For educators seeking viable alternatives to face-to-face presentation practice and feedback, the finding that immediate computer-mediated feedback is potentially as effective in aiding presentation performance is crucial for two reasons: first, it expands practice opportunities for students; second, it could result in less pressure on resources, including time and staffing.     

虚拟现实技术在化学实验教学中的应用研究

虚拟实验应用日益广泛,而支持虚拟实验的相关技术成为了研究热点。分析了虚拟化学实验及其在未来虚拟现实技术上的发展趋势,综述了U-nity3D技术、增强现实技术和Kinect体感交互技术的理论基础以及在虚拟化学实验中的应用与发展,以虚拟技术融合的方法为导向,仿真化学实验的实时环境,使虚拟实验简单化、直观化。展望了虚实融合技术在虚拟实验领域的应用前景。虚实融合技术有利于推动虚拟化学实验朝智能化发展,是虚拟实验改革的一个新起点。