对基于虚拟现实训练系统的低成本3D声音系统评估

在基于PC的虚拟训练系统中,3D的声音仿真能够大幅度的提高VR系统的能力.然而,现实的3D仿真非常昂贵,而且计算混响,阻塞和延时效果需要配置具有强大运算能力的系统.因此,必须提供一个低成本的方案,使其能在更广的范围内得到应用.对一个低成本3D声音仿真系统的评测进行了重点阐述.实验设置基于常规的立体声耳机和一个可跟踪的头戴式设备,实验中使用不同信号在虚拟训练环境中来定位声音,最后从精度和速度来表述实验结果.     

Immersive and interactive virtual reality applications based on 3D web browsers

This study explores the possibility of effectively using web-standard technologies (i.e., HTML5, JavaScript, WebGL, and WebRTC) to deploy full immersive and interactive virtual reality applications. These applications are based on computer clusters and run in multi-projection environments, such as CAVEs, Panoramas and Power Walls. Until recently, these applications were build using tailored solutions, such low-level libraries to distribute data. We discuss the modern-day web technology which allows these applications meet a multi-platform requirement. This paper also evaluates the communication and synchronization requirements of these applications that are traditionally the main bottleneck. As a proof-of-concept to show the feasibility of our study, we devised and implemented an immersive and interactive virtual reality application employing only web technologies. Our proof-of-concept runs on a miniCAVE environment with three displays and a 6-node cluster.     

Construction industry offsite production: A virtual reality interactive training environment prototype

The ‘traditional’ construction industry has constantly been challenged to improve its inherent problematic practices. Offsite production (OSP), under the umbrella of modern methods of construction (MMC), has been acknowledged as a means to help improve construction industry performance as well as meet new market demands through the provision of improved, adaptable, and sustainable buildings. However, the deployment of OSP systems, if not managed properly, may adversely affect the end result and be counterproductive. It is therefore imperative that the construction industry stakeholders learn and appreciate the specifics, merits, as well as the risks associated with OSP systems in order to achieve the desired outcomes and consequently improve industry performance.On-the-job-training (OJT) is usually sought to facilitate ‘experiential’ learning, which is argued to be particularly effective where a great deal of independence is granted to the task performer. However, OJT has been criticised for being expensive, limited, and sometimes devoid of the actual training context. In order to address the problems encountered with OJT, several virtual reality (VR) solutions have been proposed. This paper introduces one such VR solution prototype, in order to provide a risk-free environment for learning without the ‘do-or-die’ consequences often faced on real construction projects. The proffered solution provides a unique VR environment for practicing new working conditions associated with OSP practices. While the ‘scenes’ of the VR environment take place on a construction site, the environment predominantly targets professionals, such as project managers, construction managers, architects, designers, suppliers and manufacturers, to allow multidisciplinary learning to occur, and hence overcome ‘knowledge silos’ or ‘knowledge compartmentation’. The VR environment enables unforeseen problems often caused by professionals’ decisions, faulty work, and health and safety issues to occur; where the implications of which can be evaluated in respect of time, cost and resources. The VR environment proposed does not aim to resolve problems associated with OSP per se, rather aims to allow ‘things to go wrong’ and consequently allows users not only to ‘experience’ the resulting implications but also to reflect on those implications as part of the learning process. This paper discusses and presents the prototype for the first development phase of the VR interactive training environment. While the prototype was tested and validated with domain experts from industry, the research community, and academia from different EU countries, the data used in developing the prototype was constrained to one project in the UK which may limit the generalisability of results.     

The input-interface of Webcam applied in 3D virtual reality systems

Our research explores a virtual reality application based on Web camera (Webcam) input-interface. The interface can replace with the mouse to control direction intention of a user by the method of frame difference. We divide a frame into nine grids from Webcam and make use of the background registration to compute the moving object. In order to make this technology apply to 3D virtual reality system, we use the Virtools Dev to build virtual scenes and the Microsoft Visual C++ to build this interface. We also use the MySQL database management system to access users’ data and the displaying data. We implement a number of Building Blocks (BB) to support Virtools Dev for using the database management system and the Webcam input-interface in this composite system. The results of research are expected to the digital content industries such that users can easy to use the input-interface to control browsing the virtual reality. Our system can supply interactive digital content, photographs, and access the questions from the database management system. In addition, the system provides the browsing mold, the question mold, and the course content describing mold with the input-interface. In order to explore the intention of users for using the system, we design the questionnaire based on the technology acceptance model (TAM). In our empirical study, we find that perceived playfulness is positive association with attitude toward using. Interface style is positive association with perceived ease of use.     

Evaluation of a low-cost 3D sound system for immersive virtual reality training systems

Since head mounted displays (HMD), datagloves, tracking systems, and powerful computer graphics resources are nowadays in an affordable price range, the usage of PC-based "virtual training systems" becomes very attractive. However, due to the limited field of view of HMD devices, additional modalities have to be provided to benefit from 3D environments. A 3D sound simulation can improve the capabilities of VR systems dramatically. Unfortunately, realistic 3D sound simulations are expensive and demand a tremendous amount of computational power to calculate reverberation, occlusion, and obstruction effects. To use 3D sound in a PC-based training system as a way to direct and guide trainees to observe specific events in 3D space, a cheaper alternative has to be provided, so that a broader range of applications can take advantage of this modality. To address this issue, we focus in this paper on the evaluation of a low-cost 3D sound simulation that is capable of providing traceable 3D sound events. We describe our experimental system setup using conventional stereo headsets in combination with a tracked HMD device and present our results with regard to precision, speed, and used signal types for localizing simulated sound events in a virtual training environment     

Using virtual reality and 3D industrial numerical models for immersive interactive checklists

At the different stages of the PLM, companies develop numerous checklist-based procedures involving prototype inspection and testing. Besides, techniques from CAD, 3D imaging, animation and virtual reality now form a mature set of tools for industrial applications. The work presented in this article develops a unique framework for immersive checklist-based project reviews that applies to all steps of the PLM. It combines immersive navigation in the checklist, virtual experiments when needed and multimedia update of the checklist. It provides a generic tool, independent of the considered checklist, relies on the integration of various VR tools and concepts, in a modular way, and uses an original gesture recognition. Feasibility experiments are presented, validating the benefits of the approach.     

A systematic review of the application of interactive virtual reality to sport

Virtual reality (VR) technology is being increasingly used by athletes, coaches, and other sport-related professionals. The present systematic review aimed to document research on the application of VR to sport to better understand the outcomes that have emerged in this work. Research literature databases were searched, and the results screened to identify articles reporting applications of interactive VR to sport with healthy human participants. Twenty articles were identified and coded to document the study aims, research designs, participant characteristics, sport types, VR technology, measures, and key findings. From the review, it was shown that interactive VR applications have enhanced a range of performance, physiological, and psychological outcomes. The specific effects have been influenced by factors related to the athlete and the VR system, which comprise athlete factors, VR environment factors, task factors, and the non-VR environment factors. Important variables include the presence of others in the virtual environment, competitiveness, task autonomy, immersion, attentional focus, and feedback. The majority of research has been conducted on endurance sports, such as running, cycling, and rowing, and more research is required to examine the use of interactive VR in skill-based sports. Additional directions for future research and reporting standards for researchers are suggested.     

The Java 3D API and virtual reality

Java programmers can quickly and easily define graphics programs using Java 3D's scene graph classes. An expanded view model lets applications seamlessly operate in a variety of single- and multiple-display, nonhead-tracked and head-tracked, display environments. This view model relies on the flexible InputDevice interface that Java 3D provides to remove most of the vagaries of hardware trackers     

A multimodal virtual reality interface for 3D interaction with VTK

The object-oriented visualization Toolkit (VTK) is widely used for scientific visualization. VTK is a visualization library that provides a large number of functions for presenting three-dimensional data. Interaction with the visualized data is controlled with two-dimensional input devices, such as mouse and keyboard. Support for real three-dimensional and multimodal input is non-existent. This paper describes VR-VTK: a multimodal interface to VTK on a virtual environment. Six degree of freedom input devices are used for spatial 3D interaction. They control the 3D widgets that are used to interact with the visualized data. Head tracking is used for camera control. Pedals are used for clutching. Speech input is used for application commands and system control. To address several problems specific for spatial 3D interaction, a number of additional features, such as more complex interaction methods and enhanced depth perception, are discussed. Furthermore, the need for multimodal input to support interaction with the visualization is shown. Two existing VTK applications are ported using VR-VTK to run in a desktop virtual reality system. Informal user experiences are presented. Arjan J. F. Kok is an assistant professor at the Department of Computer Science at the Open University of the Netherlands. He studied Computer Science at the Delft University of Technology, The Netherlands. He received his Ph.D. from the same university. He worked as a Scientist for TNO (Netherlands Organization for Applied Scientific Research) and as assistant professor at the Eindhoven University of Technology before he joined the Open University. His research interests are visualization, virtual reality, and computer graphics. Robert van Liere studied Computer Science at the Delft University of Technology, the Netherlands. He received his Ph.D. with the thesis “Studies in Interactive Scientific Visualization” at the University of Amsterdam. Since 1985, he has worked at CWI, the Center for Mathematics and Computer Science in Amsterdam in which he is the head of CWI’s visualization research group. Since 2004, he holds a part-time position as full professor at the Eindhoven University of Technology. His research interests are in interactive data visualization and virtual reality. He is a member of IEEE.     

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煤矿安全培训系统

针对传统煤矿安全培训手段单一、效果不理想的问题,提出了基于虚拟现实技术的煤矿安全培训系统。该系统应用虚拟现实开发软件3DS MAX和Virtools DEV来完成设备建模、场景构建和交互式系统的开发,实现了煤矿风险预控、事故案例再现和事故应急救援的仿真。应用结果表明,该系统通过三维仿真和交互形式可有效提高煤矿安全培训的针对性和实施效果,达到提高安全意识、减少安全事故的目的。     

基于虚拟现实技术的煤矿安全培训系统

针对传统煤矿安全培训手段单一、效果不理想的问题,提出了基于虚拟现实技术的煤矿安全培训系统。该系统应用虚拟现实开发软件3DS MAX和Virtools DEV来完成设备建模、场景构建和交互式系统的开发,实现了煤矿风险预控、事故案例再现和事故应急救援的仿真。应用结果表明,该系统通过三维仿真和交互形式可有效提高煤矿安全培训的针对性和实施效果,达到提高安全意识、减少安全事故的目的。     

A PC-based high-quality and interactive virtual endoscopy navigating system using 3D texture based volume rendering

As an alternative method to optical endoscopy, visual quality and interactivity are crucial for virtual endoscopy. One solution is to use the 3D texture map based volume rendering method that offers high rendering speed without reducing visual quality. However, it is difficult to apply the method to virtual endoscopy. First, 3D texture mapping requires a high-end graphic workstation. Second, texture memory limits reduce the frame-rate. Third, lack of shading reduces visual quality significantly. As 3D texture mapping has become available on personal computers recently, we developed an interactive navigation system using 3D texture mapping on a personal computer. We divided the volume data into small cubes and tested whether the cubes had meaningful data. Only the cubes that passed the test were loaded into the texture memory and rendered. With the amount of data to be rendered minimized, rendering speed increased remarkably. We also improved visual quality by implementing full Phong shading based on the iso-surface shading method without sacrificing interactivity. With the developed navigation system, 256 x 256 x 256 sized brain MRA data was interactively explored with good image quality.     

OpenGL技术在虚拟现实三维重建中的应用

目前,利用专业三维建模软件很难实现虚拟现实所需要的交互性,同时,在OpenGL建立的虚拟现实环境中,也很难通过编程进行复杂的三维建模.因此通过研究比较现在常用的利用OpenGL创建3D模型的方法,提出了一种新方法,即利用3DSMax进行复杂建模,并将模型导出为3DS格式,然后通过在OpenGL下编程控制模型来达到对虚拟现实环境的仿真.最后,利用该方法成功模拟了一个交通事故现场的虚拟环境,并可以对环境中的车辆等事物进行编程控制.     

ERT-VR: an immersive virtual reality system for emergency rescue training

Virtual reality technology offers a cost effective means to train emergency rescuers, which is an urgent task on account of the increasing terrorist acctivities. An immersive virtual reality system called ERT-VR is introduced. In ERT-VR, the display system based on stereoscopic projectors is used to train the emergency rescue commanders. The members of the operational teams use head-mounted display as the display system. The 3D scenario creator is the most important unit in ERT-VR. Instructors assign a specific training scenario to the trainees by using the scenario creator. Trainees take on the role of the characters in the training scenario and control their actions and ultimately the scenario outcomes. All the actions are recorded into the database system and can be replayed anytime. The potential of each trainee is evaluated by an expert system.     

Unity game engine: interactive software design using digital glove for virtual reality baseball pitch training

Microsystem Technologies - This paper proposes a novel baseball pitch training software design to interact with a virtual object in a virtual reality or augmented reality environment by combining a...     

A domain-oriented end-user design environment for generating interactive 3D virtual chemistry experiments

Three-dimensional virtual worlds are potentially feasible for building virtual educational environments. However, educators face technical challenges to apply these technologies because creating virtual educational environments based on virtual worlds demands 3D modeling and programming skills. This paper proposes a method to lower the technical barriers through domain-oriented interfaces with languages and environments that are familiar to educators. A domain-oriented end-user design environment, iVirtualWorld, is designed and developed to implement the proposed method in a specific educational domain, namely introductory chemistry experiments. This web-based environment provides end-users with domain-oriented building blocks, which can be assembled to create 3D virtual chemistry experiments. A usability evaluation and a comparative case study are designed to evaluate the system among chemistry educators, who are the target audience. The usability evaluation contains a task requiring participants to create a 3D virtual chemistry experiment and a voluntary semi-structured interview. The case study compares a virtual experiment generated using iVirtualWorld with an experiment in a commercial virtual chemistry laboratory system. The results show that 1) the domain-oriented end-user design environment enables participants to generate the 3D virtual chemistry experiment within 30 min; 2) participants gain confidence on creating 3D virtual experiments by themselves using iVirtualWorld; 3) participants confirm the usefulness of applying the system in introductory chemistry education; and 4) iVirtualWorld is considered more intuitive and straightforward for students to focus on finishing the experiment without being distracted than the commercial virtual chemistry laboratory system. Areas that can benefit from the system most and areas where the system is less effective are identified by participants. The responses also reveal the limitations of the current system and suggest directions for future improvement.     

A real-time interactive virtual classroom multimedia distancelearning system

In this paper, we present the design and development of a real-time interactive virtual classroom multimedia distance learning system at the University of Washington. There has been rapid progress in digital media compression research, and the delivery of media data on the public Internet is becoming widespread. A real-time interactive virtual classroom allows a remote participant to not only receive a live class feed, but also to interact in a live class by asking questions with audio, video in real-time using an Internet connection. Many instructors use electronically prepared slides during their class. The traditional video coding algorithms are not able to compress this slide data very well at low bit-rates. We propose a Web-based real-time presentation system for the electronic slides. Instructors also write text on a white board or a piece of paper during the class. At low bit-rates, conventional video encoding algorithms cannot encode this handwritten text video with enough fidelity, resulting in an illegible decoded video. We propose an extension of the well known bilevel image encoding algorithms to handle the handwritten text video. Our method results in decoded video frames which can be read very clearly when encoded at low bit-rates. We have developed a set of tools which allows recording the live classroom session and automatic creation of a synchronized multimedia integration language (SMIL) presentation, which can be used for a later viewing     

A review of immersive virtual reality serious games to enhance learning and training

Multimedia Tools and Applications - The merger of game-based approaches and Virtual Reality (VR) environments that can enhance learning and training methodologies have a very promising future,...     

A PC-based distributed multiple display virtual reality system

In this paper, a PC-based distributed multiple-display virtual reality system is constructed. The system is a PC-based CAVE environment. Five PCs are used in this system; one is the master responsible for receiving user's input signals, the others are clients for images rendering. Devices are added to synchronize the RGB signals from client PCs.

A software library is developed to drive the system properly. The software is designed in object-oriented language and flexibility for different interface devices is considered.

With the proposed system, developers can easily elaborate PC-based virtual reality applications and build PC virtual worlds at much lower cost.