Virtual Reality Interfaces for Visualization and Control of Remote Vehicles

The Autonomy and Robotics Area (ARA) at NASA Ames Research Center has investigated the use of various types of Virtual Reality-based operator interfaces to remotely control complex robotic mechanisms. In this paper, we describe the major accomplishments and technology applications of the ARA in this area, and highlight the advantages and issues related to this technology.     

Brain-Computer Interfaces, Virtual Reality, and Videogames

Major challenges must be tackled for brain-computer interfaces to mature into an established communications medium for VR applications, which will range from basic neuroscience studies to developing optimal peripherals and mental gamepads and more efficient brain-signal processing techniques.     

Distributed Virtual Reality Authoring Interfaces for the WWW: The VR-Shop Case

Electronic commerce is emerging as an important domain of integration and enhancement of more specific technologies and research efforts. It is clear that the role of WWW in this context is a cornerstone as the medium of information dissemination. A trend in e-commerce is to provide to the potential customers the ability to view and try the products in a persuasive 3D representation. We have designed and implemented a system for WWW enabled interactive design & visualization of a room, definition of pieces of furniture and placement of domestic appliances. The system conveys a generic approach for distributed creation and update of virtual worlds as means of interaction and information dissemination in an e-commerce context.     

Opportunistic Tangible User Interfaces for Augmented Reality

Opportunistic Controls are a class of user interaction techniques that we have developed for augmented reality (AR) applications to support gesturing on, and receiving feedback from, otherwise unused affordances already present in the domain environment. By leveraging characteristics of these affordances to provide passive haptics that ease gesture input, Opportunistic Controls simplify gesture recognition, and provide tangible feedback to the user. In this approach, 3D widgets are tightly coupled with affordances to provide visual feedback and hints about the functionality of the control. For example, a set of buttons can be mapped to existing tactile features on domain objects. We describe examples of Opportunistic Controls that we have designed and implemented using optical marker tracking, combined with appearance-based gesture recognition. We present the results of two user studies. In the first, participants performed a simulated maintenance inspection of an aircraft engine using a set of virtual buttons implemented both as Opportunistic Controls and using simpler passive haptics. Opportunistic Controls allowed participants to complete their tasks significantly faster and were preferred over the baseline technique. In the second, participants proposed and demonstrated user interfaces incorporating Opportunistic Controls for two domains, allowing us to gain additional insights into how user interfaces featuring Opportunistic Controls might be designed.     

分布式虚拟现实

该文首先介绍了分布式虚拟现实的基本概念和它所面临的挑战，以ＤＩＳ标准为中心，较详细地讨论了一些有关ＤＶＲ具体的思想和技术，是了后介绍了一些典型的ＤＶＲ系统和工具。     

虚拟现实技术的“嗅频”解决方案

随着计算机硬件及软件技术的飞速发展,目前计算机视频及音频技术有了重大的突破,虚拟现实(VirtualRe-ality)技术应运而生,而计算机的“嗅频”技术仍缓步不前。有分析显示,气味较图像更吸引人。该文提出的虚拟现实技术的嗅频解决方案,可以说是对传统的虚拟现实技术的必要补充。文章从分子角度探讨了基于QSAR(定量结构活性关系)的气味识别理论,介绍了SuperScent气味分析专业软件的功能实现方案,说明了用于气味识别的气味识别子系统的实现原理和用于气味发生的气味发生子系统的实现方案。     

RCVL系统中的虚拟现实技术

虚拟现实是９０年代发展起来的新技术。详细讨论了利用虚拟现实开发ＲＣＶＬ系统的关键技术,包括系统设计目标,系统功能划分,ＶＲＭＬ场景的设计以及外部控制技术。     

虚拟现实工具

本文介绍了３Ｄ位置传感器、传感手套，视觉设备、３Ｄ声音设备等一些常见的ＶＲ工具，以及物体的３Ｄ位置描述、手指移动术语，人眼立体视觉原理、人的听觉模型等基本知识。     

Output-SensitiveVisibility Algorithms for Dynamic Scenes with Applications to Virtual Reality

An output-sensitive visibility algorithm is one whose runtime is proportional to the number of visible graphic primitives in a scene model—not to the total number of primitives, which can be much greater. The known practical output-sensitive visibility algorithms are suitable only for static scenes, because they include a heavy preprocessing stage that constructs a spatial data structure which relies on the model objects’ positions. Any changes to the scene geometry might cause significant modifications to this data structure. We show how these algorithms may be adapted to dynamic scenes. Two main ideas are used: first, update the spatial data structure to reflect the dynamic objects’ current positions; make this update efficient by restricting it to a small part of the data structure. Second, use temporal bounding volumes (TBVs) to avoid having to consider every dynamic object in each frame. The combination of these techniques yields efficient, output-sensitive visibility algorithms for scenes with multiple dynamic objects. The performance of our methods is shown to be significantly better than previous output-sensitive algorithms, intended for static scenes. TBVs can be adapted to applications where no prior knowledge of the objects’ trajectories is available, such as virtual reality (VR), simulations etc. Furthermore, they save updates of the scene model itself; notjust of the auxiliary data structure used by the visibility algorithm. They can therefore be used to greatly reduce the communications overhead in client-server VR systems, as well as in general distributed virtual environments.     

在Vega环境下开发虚拟现实应用程序

Vega是目前流行的虚拟现实应用程序开发环境。与Vega环境相关的应用程序还有三维建模工具Creator和虚拟场景集成工具Lynx。该文介绍了虚拟现实应用程序区别于动画的主要特征,分析了Vega开发环境的主要特点及各个模块的功能。简要介绍了Creator和Lvnx的功能以及Vega与Creator、Lynx软件之间的相互关系,重点讨论了在Vega环境下开发虚拟现实应用程序的主要过程,并描述了控制台风格的Vega应用程序结构基本框架。     

基于网络的虚拟现实技术

网络虚拟现实技术代表着未来计算机的应用技术,它为地理上分散的用户提供了一种可以交流与合作的共享空间,文章概述了虚拟现实的三要素、替身和显示技术,以及实现网络虚拟现实的一些关键技术,诸如网络联结、通讯协议、通讯方式、推测技术等。最后,介绍了一种用于Ｗｅｂ上的虚拟现实建模语言ＶＲＭＬ。     

虚拟现实技术导论

本文介绍了虚拟现实的基本概念，基本技术，发展历史和应用领域。     

Augmented and Virtual Reality techniques for footwear

The use of 3D imaging techniques has been early adopted in the footwear industry. In particular, 3D imaging could be used to aid commerce and improve the quality and sales of shoes. Footwear customization is an added value aimed not only to improve product quality, but also consumer comfort. Moreover, customisation implies a new business model that avoids the competition of mass production coming from new manufacturers settled mainly in Asian countries.     

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。     

一种面向多视频源的虚拟现实系统解决方案

虚拟现实系统的实现原理是通过传感器、效应器等外设将用户"集成"到现实发生器产生的模拟环境中,以实现虚拟现实所必须的3I.在实际应用中,一般要求作为效应器的投影显示系统能够满足现实发生器、普通PC机、DVD、摄像机等多个视频源的投影显示需求,为此,该文提出一种面向多源视频信息的虚拟现实系统解决方案,该方案通过一个中央控制系统使得多个现实发生器和PC机、DVD、摄像机等视频源共享投影系统,大大提高了投影系统的使用效率,同时满足了用户多种应用平台的需求,具有较大的实用价值.在介绍了该方案的总体思路后,对各分系统进行了详细分析.     

浅析虚拟现实技术

虚拟现实技术是一门综合性很强的高新技术,该技术被广泛应用于先进制造、军事模拟、数字城市、生物医学等众多领域.本文追溯了虚拟现实技术的起源,探讨了该技术的三大特点:沉浸感、交互性和构想性,并根据沉浸的不同程度将虚拟现实技术分为四大类型:桌面式虚拟现实、沉浸式虚拟现实、增强现实的虚拟现实以及分布式虚拟现实.     

虚拟现实实验中虚拟植物的建模

虚拟植物技术对作物产量预测、土地生产力评价、资源环境分析、作物栽培指导、作物生长机理研究以及调控作物生长发育及其对环境的反应研究都有着十分重要的意义。目前虚拟植物普遍使用的玉米叶脉曲线拟合曲线函数在叶尖坐标Y不是最大坐标的时候，不能很好地描述叶曲线。该文以玉米叶子的中脉为轴线，贴合玉米叶子的平面纹理图像。将玉米叶子中脉表达成3次B样条曲线，实施空间变形，再将纹理图像嵌入到变形后玉米叶脉曲线的局部标架中。该方法在叶尖坐标是否最大坐标时都适用，直接进行曲线拟合，而不必进行叶片角度旋转，绘制出的玉米叶子具有叶子的脉络细节，真实感较强。     

基于Internet的虚拟现实交互技术

虚拟现实技术代表了未来计算机技术的发展方向，本文概述第二代WWW技术和其影响，着重讨论了在In-ternet上实现虚拟现实交互的一些核心技术和虚拟现实的实现语言VRML，最后给出了例子说明。