Virtual environments for engineering applications

Virtual reality (VR), provides the user with an ego-centred human-computer interaction environment by presenting the data as a computer-generated 3D virtual environment. This enables the user to be immersed in this world via user position tracking devices and to interact with the data objects in the world in intuitive ways. This paper describes a selection of VR simulations for engineering applications implemented in CLRC which demonstrate the potential of VR interaction techniques to offer quicker and possibly better understanding of spatial relationships and temporal patterns inherent in large data sets. Two of the case studies have been implemented to support engineers communicate and review their designs with scientists, managers and manufacturers and to plan their assembly and maintenance work in hazardous physical environments. The other two applications are visualisation case studies based on data sets generated by computational engineering simulations. The case studies are real world applications, involving end-users of large or complex data sets. Insight gained into the user interaction requirements through the implementation and user comments is guiding ongoing research and development activity and this is discussed briefly.     

Evaluating the usability of virtual reality user interfaces

A walkthrough method for evaluating virtual reality (VR) user interfaces is described and illustrated with a usability assessment of a virtual business park application. The method is based on a theory of interaction that extends Norman's model of action. A walkthrough analysis method uses three models derived from the theory. The first model describes goal-oriented task action, the second exploration and navigation in virtual worlds, while the third covers interaction in response to system initiative. Each stage of the model is associated with generic design properties that specify the necessary support from the system for successful interaction. The evaluation method consists of a checklist of questions using the properties and following the model cycle. Use of the method uncovered several usability problems. Approaches to evaluation of VR applications and future work are discussed.     

Evaluating the usability of virtual reality user interfaces

A walkthrough method for evaluating virtual reality (VR) user interfaces is described and illustrated with a usability assessment of a virtual business park application. The method is based on a theory of interaction that extends Norman's model of action. A walkthrough analysis method uses three models derived from the theory. The first model describes goal-oriented task action, the second exploration and navigation in virtual worlds, while the third covers interaction in response to system initiative. Each stage of the model is associated with generic design properties that specify the necessary support from the system for successful interaction. The evaluation method consists of a checklist of questions using the properties and following the model cycle. Use of the method uncovered several usability problems. Approaches to evaluation of VR applications and future work are discussed.     

用户认知驱动的VR自然交互认知负荷研究

针对目前虚拟现实自然交互系统中用户认知负荷难以量化问题,以量化认知负荷为目的,提出一种基于概率神经网络的多通道信息融合模型。首先根据认知理论建立“认知—行为—环境”框架,并在此基础上研究用户认知的数学表征（方法,过程,机理）,构建多通道认知模型;然后将多通道信息融合方法引入虚拟现实自然交互系统,建立一种面向虚拟现实自然交互系统的认知负荷模型;通过VR隧道应急救援系统实验对系统中用户认知进行验证。验证结果表明,具体提出的认知负荷模型具有一定的可行性。     

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.     

基于Web的虚拟展厅的设计与实现

当前的VR标准，可以描述一个被动的VR系统，即系统应用VR技术来实现一些预先设计的3D内容的可视化。然而，现实中的一个挑战在于构造主动VR应用，这种应用允许动态合成虚拟场景。为了能构造主动VR应用，该文结合目前工作描述了网络环境下虚拟展览厅系统，提出虚拟世界的数据库建模方法。文中阐述了该系统的用途和功能，给出了系统的结构模型等。     

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.     

基于事件的虚拟现实用户体验评估方法研究

近年来,随着虚拟现实(Virtual Reality,VR)技术的逐渐成熟,我国VR产业处于高速增长的态势.虽然VR的发展为内容设计提供了许多新的可能性,但由于VR应用的设计不成熟,VR行业的从业者们仍面临着严峻的挑战,VR中的设计仍需要通过用户使用来验证是否可行.因此,用户体验(User Experience,UX)...     

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。     

VR-Rides: An object-oriented application framework for immersive virtual reality exergames

Exercise can improve health and well-being. With this in mind, immersive virtual reality (VR) games are being developed to promote physical activity, and are generally evaluated through user studies. However, building such applications is time consuming and expensive. This paper introduces VR-Rides, an object-oriented application framework focused on the development of experiment-oriented VR exergames. Following the modular programming pattern, this framework facilitates the integration of different hardware (such as VR devices, sensors, and physical activity devices) within immersive VR experiences that overlay game narratives on Google Street View panoramas. Combining software engineering and interaction patterns, modules of VR-Rides can be easily added and managed in the Unity game engine. We evaluate the code efficiency and development effort across our VR exergames developed using VR-Rides. The reliability, maintainability, and usability of our framework are also demonstrated via code metrics analysis and user studies. The results show that investing in a systematic approach to reusing code and design can be a worthwhile effort for researchers beyond software engineering.     

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.     

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。     

Head-mounted display versus desktop for 3D navigation in virtual reality: a user study

Virtual Reality (VR) has been constantly evolving since its early days, and is now a fundamental technology in different application areas. User evaluation is a crucial step in the design and development of VR systems that do respond to users’ needs, as well as for identifying applications that indeed gain from the use of such technology. Yet, there is not much work reported concerning usability evaluation and validation of VR systems, when compared with the traditional desktop setup. The paper presents a user study performed, as a first step, for the evaluation of a low-cost VR system using a Head-Mounted Display (HMD). That system was compared to a traditional desktop setup through an experiment that assessed user performance, when carrying out navigation tasks in a game scenario for a short period. The results show that, although users were generally satisfied with the VR system, and found the HMD interaction intuitive and natural, most performed better with the desktop setup.

ISRE: immersive scenario-based requirements engineering with virtual prototypes

Virtual prototyping is a useful approach for refining requirements for complex designs. However, the use of virtual reality (VR) technology can cause usability problems that can be interpreted as false positive requirements errors. The immersive scenario-based requirements engineering (ISRE) method guides the analysis of problems encountered during the testing of virtual prototypes and helps assign causes to either genuine requirements defects or to usability issues with VR technology. The method consists of techniques for walkthrough testing, testing with users, causal analysis of observed problems and the design of scenario-based analysis sessions. The method is described and its use illustrated with a case study of validating requirements for an aircraft maintenance application.     

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。     

Haptic Direct-Drive Robot Control Scheme in Virtual Reality

This paper explores the use of a 2-D (Direct-Drive Arm) manipulator for mechanism design applications based on virtual reality (VR). This article reviews the system include a user interface, a simulator, and a robot control scheme. The user interface is a combination of a virtual clay environment and human arm dynamics via robot effector handler. The model of the VR system is built based on a haptic interface device behavior that enables the operator to feel the actual force feedback from the virtual environment just as s/he would from the real environment. A primary stabilizing controller is used to develop a haptic interface device where realistic simulations of the dynamic interaction forces between a human operator and the simulated virtual object/mechanism are required. The stability and performance of the system are studied and analyzed based on the Nyquist stability criterion. Experiments on cutting virtual clay are used to validate the theoretical developments. It was shown that the experimental and theoretical results are in good agreement and that the designed controller is robust to constrained/unconstrained environment.     

Virtual Reality Interfaces for Interacting with Three-Dimensional Graphs

Today, virtual reality (VR) systems are widely available through low-cost devices such as Oculus Rift and HTC Vive. Although VR technology has so far been centered on entertainment, there is a growing interest from developers, technology companies, and consumers to evaluate it in a wider variety of contexts. This paper explores the effectiveness of visualizing and interacting with three-dimensional graphs in VR in comparison with the traditional approach. In particular, we present an empirical evaluation study for exploring and interacting with three-dimensional graphs using Oculus Rift and Leap Motion. We designed several interfaces exploiting the natural user interface in a VR environment and compared them with traditional mouse–keyboard and joypad configurations. Our evaluation suggests that, although these upcoming VR technologies are more challenging than more traditional ones, they facilitate user involvement during graph interaction and visualization tasks, given the enjoyable experience elicited when combining gesture-based interfaces and VR.     

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.     

新型虚拟现实交互建模方法

给出一种虚拟现实交互建模的方法。设计了一种新型建模工具VRTool,提出了交互性建模的拓扑模型和视角跟踪导航模型,解决了交互建模的定位坐标数据源问题和线性速度突变问题,其优点在于能够方便人与三维模型之间交互关系以及三维导航运动模型的建立。实验结果表明了该建模方法的可靠有效性,为虚拟现实建模工具的发展提供了新的思路。