基于Jini支持X3D的虚拟场景浏览器的研究与探索

基于Jini技术的虚拟实验平台的设计与实现
杨春;余毅;吴微;谭良
【期刊名称】《电子科技大学学报》
【年(卷),期】2008(037)001
【摘要】运用Jini技术的基本原理和优势特点,针对化学虚拟实验系统,引入协同支撑服务机制,构建了一种面向服务的虚拟实验平台,详细阐述了其功能与构架;基于Java面向对象设计语言中的接口定义了实验平台的相关操作规则及系列面向服务的接口,以铁与硫酸反应的实例说明了该实验平台的工作原理与流程.结果表明系统具有易扩充、较好的可靠性、且能动态反映虚拟实验过程,提供了在现有网络基础下的分布式实现三维虚拟实验的一种新方案.
【总页数】4页(P86-89)
【作者】杨春;余毅;吴微;谭良
【作者单位】四川师范大学计算机软件重点实验室,成都,610066;四川师范大学学报(自然科学版)编辑部,成都,610066;四川师范大学计算机软件重点实验室,成都,610066;四川师范大学计算机软件重点实验室,成都,610066
【正文语种】中文
【中图分类】TP393.02
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5.基于Flash技术的学校生物虚拟实验平台设计与实现 [J], 周孟玥;黎云祥;周玲因版权原因，仅展示原文概要，查看原文内容请购买。

WebGL技术在虚拟现实环境中的应用研究近年来，随着虚拟现实技术的迅猛发展，WebGL技术也逐渐被应用于虚拟现实环境中。

WebGL是一种基于OpenGL的3D图形API，在Web平台上提供硬件加速的图形渲染能力，支持浏览器实时生成和呈现3D模型，为虚拟现实技术提供了有力的支持。

一、WebGL技术简介WebGL技术是一种网页3D图形技术，是一种基于OpenGL ES 2.0的开放标准，它使用JavaScript语言编写程序，可以在浏览器端实现硬件加速的3D图形渲染。

WebGL使用的是HTML5、CSS3和JavaScript等技术，用于在任何支持WebGL技术的浏览器上制作动态的3D交互场景。

二、WebGL技术在虚拟现实中的应用1. 虚拟现实游戏虚拟现实游戏是WebGL技术应用的一大领域，它可以在浏览器中实时生成3D 游戏场景，为用户提供沉浸式的游戏体验。

用户可以通过VR头显设备和手柄来控制游戏角色的移动和操作，可以与其他玩家进行实时互动。

2. 虚拟现实教育虚拟现实教育是利用虚拟现实技术来创造出真实感和沉浸感的学习环境，帮助学生更好地理解课程内容，将抽象的概念转化为具体的实践。

利用WebGL技术，可以在浏览器上实现虚拟现实实验室、虚拟现实图书馆、虚拟现实考古等应用，提高教育效果。

3. 虚拟现实计算机辅助设计计算机辅助设计是一种将计算机科学与设计领域结合起来的技术，它可以帮助用户快速生成复杂的3D模型和动画，并进行实时的模拟和分析。

利用WebGL技术，可以在浏览器中实时渲染大规模复杂的3D模型，提高计算机辅助设计的效率。

4. 虚拟现实医疗虚拟现实医疗是利用虚拟现实技术来创造出真实感和沉浸感的医疗环境，帮助医生提高诊断和治疗能力。

利用WebGL技术，可以在浏览器中实现虚拟手术、虚拟康复等应用，提高医疗效果和效率。

三、WebGL技术的优势和挑战WebGL技术作为一种新兴的浏览器3D图形技术，具有以下优势：1. 跨平台和无需安装：WebGL技术不需要安装任何插件或软件，只需要打开支持WebGL技术的浏览器即可。

基于空间信息技术的地下空间三维导示系统的研究吕淑贤;黄锰钢;靳金【摘要】本文简述了城市地下空间三维智能导示系统.该系统结合GPS、GIS、RS 以及网络通信等技术,对整个地下空间信息道路进行三维模拟仿真和最短路径的查询.通过该系统,用户可以自由选择二维或者三维显示界面,快速查找出到达目的地的所有路线以及乘车方法和所需时间,并指示出最优路线.系统还可以提供专门为残疾人设置的嵌入式语音和触摸提示功能.通过仿真结果,证明该系统是可行的并且能够给人们带来方便、提高效率.【期刊名称】《土木建筑工程信息技术》【年(卷),期】2010(002)004【总页数】8页(P26-33)【关键词】地下空间;3S技术(GPS,GIS,RS);三维智能导示系统;Dikjstra算法;网络通信技术;三维显示【作者】吕淑贤;黄锰钢;靳金【作者单位】韩国延世大学生活学院居住环境专业;韩国延世大学土木环境工程学院;韩国庆熙大学土木系【正文语种】中文【中图分类】TU921;TP391.9This paper demonstrates a 3D intelligent system of urban underground space guidance.One critical problem of existing guidance systems for theunderground space is that they mostly deal with two-dimensional images.Moreover，current systems are also not very intuitionist and thus bring troubles in understanding.On the other hand，the functions of current systems are insufficient，e.g.inconvenient for underprivileged group.In this paper，we design a novel underground space guidance system that can provide helpful information to guide people to travel in the underground intelligently and conveniently.The system can be easily deployed in underground space.Different from most previous systems，it adopts Three-dimensional（3D）simulation technology that cooperates with dynamic display technology，integrating of GPS，GIS，RS computing technology and communication networks.Through this approach，users can find and be guided to their destination quickly.Meanwhile，the system can also offer assistant functions，such as the potential to assist the mobility of the disabled with the application-embedded Voice and Touch prompt functions，internet accessibility etc.The results of simulation show this guidance system is not only feasible but also have effective performance.3D Intelligent Guidance System；3S（GPS，GIS，RS）Dikjstra-algorithm；3D Viewpoint；Communication Networks；Underground Space ［Chinese Library Classfication］TU921；TP391.9 ［Documeut Code］A ［Article ID］1674－7461（2010）04－0026－08Owing to the development of the cubic construction of the modern cities the functions of underground space have become important in many cities.With the growth of population，the use of underground spaces hasbeen increased.Especially the subway construction will increase the total scale of underground space development（Liguo et al.，1991）.In our daily life，there are many systems whith give us navigation.One is the car navigation system，which hascommon application in finding one's way in an unfamiliar public place.An automotive navigation system is a satellite navigation system designed for use in automobiles.It typically uses a GPS navigation device to acquire position data to locate the user on a road in the unit＇s map ing the road database，the unit can give directions to other locations along roads also in its database.Dead reckoning using distance data from sensors attached to the drivetrain，a gyroscope and an accelerometer can be used for greater reliability，as GPS signal loss and／or multipath can occur due to urban canyons or tunnels（James R.Akerman，2006；Nakayama，O，1989；Nowakowski；2003；Kim，2002）.The other is pedestrian navigation system，such as uNavi（Bessho et al.，2008b），which assists users to freely navigate both indoor and outdoor along with the road map.uNavi utilizes landmark-based guidance by showing still photograph and text information of each landmark in addition to the traditional map based guidance.There are always limited numbers of available photographs in real situation.Unlike the above system，the key issue of existing guidance systems of underground space is that they mostly deal with two-dimensional images and most current systems are confined to the underground without considering the situation on the ground.The current systems have troubles being understood due to lack of intuitionism On the other hand，thefunctions of current system are insufficient，e.g.incompatible for underprivileged group.To solve this problem，we have proposed to design a novel underground space guidance system-Three-Dimensional Guidance System（3DGS）that will provide helpful information to guide people travel in the underground intelligently and conveniently.The system can be easily deployed in underground space.Different from most previous systems，it adopts 3D simulation technology that cooperates with dynamic display technology.People can choose the hot points in 3D interface via the touch screen；It can enable users to search intuitively by specify key words and provide users many routes with the time duration，including the optimum one.Through this approach，users can find out the destination and be guided quickly.Meanwhile，the system can also offer assistant functions，such as the potential to assist the mobility of the disabled with the application-embedded Voice and Touch prompt functions，internet accessibility etc.We will deploy our system in several underground sites.There are many valuable works about the navigation capability and they are already usedas a tour guiding service in many countries.In this paper，we focus on its deployment on underground space guidance.This system provides all the space navigation including ground and underground interfaces using text，audio and 3D images in additional to the traditional map based guidance.In addition，the system also provides several advances for the disabled.The remaining part of this paper is structured as follows.We outline theframework for our guidance system in Section 2.Then，its implementation is described in Section 3.Based on the simulation through 3D virtual technology，the feasibility and effectiveness of result is discussed in Section 4.The last section is the conclusion.1.1 OverviewThe Global Positioning System（GPS）is a space-based global navigation satellite system that provides reliable location and time information in all weather and at all times and anywhere on or near the Earth when and where there is an unobstructed line of sight to four or more GPS satellites.It is maintained by the United States government and is freely accessible by anyone with a GPS receiver（Agnew，2007；Massatt，2002；Michael Russell Rip，2002）.Because of the limitation of GPS veracity for underground space，the 3DGS requires more precise services for the common public facilities underground space.There is no single technology that can offer and overcome the accuracy problem.Besides using GPS，GIS technology also has been used in guidance system.Geographic information systems（GIS）or geospatial information systems are sets of tools that captures，stores，analyzes，manages，andpresents data that are linkedto location（s）.In the simplest terms，GIS is the merging of cartography，statistical analysis，and database technology.GIS systems are used in cartography，remote sensing，land surveying，public utility management，natural resource management，photogrammetry，geography，urban planning，emergency management，navigation，aerial video，and localized search engines（Chang.1989 and 2008；Clarke，1986；Michael，2010）.In addition，some other technologies also have been proposed，such as RFIDs（Liu et al.，2006），the multiple space-identifying devices （Bessho et al.，2008a，Bessho et al.，2007）are some of them.Radio-frequency identification（RFID）is the use of an object（typically referred to as an RFID tag）applied to or incorporated into a product，animal，or person for the purpose of identification and tracking using radio waves.Some tags can be read from several meters away and beyond the line of sight of the reader.On the other hand，the multiple space-identifying approach integrates ubiquitously-deployed multiple space-identifying devices including active and passive RFIDs，and infrared beacons to realize accurate navigation.The main advantage of this approach is the abstraction of space-identifying devices provided by the unique identifier framework，which realizes flexible and extensible device integration.The 3DGS based on a large amount of data，and the main one is the real world data including timetable data，road network data，subway data，transportation information and the other is on location information data.GPS，Indoor GIS location service help to associate precise information service to the underground space.In this infrastructure，each place is assigned as its own unique coordinate identifier and is attached with device transmitting the identifier.Figure1 is The space information dynamic service system model.Associated with these data，the system can automatically analyze on the basis of Dijstra-algorithm and display the appropriate guidance for users from the underground space todestination.The interface of 3DGS will display 3D viewpoint to users and more visualized than 2D video mode.In order to provide assistance and convenience to disabled users，the system also adds some devices for them.1.2 Implementation（1）Algorithm（computing）There are many algorithms that can compute the shortest path problem.But the main central Concept comes from Dikjstra-algorithm （Dijkstra，1959）which is based on point-to-point search strategy.The data information is considered as the foundation for 3DGS and then according to Dijstra-algorithm many routes and required time have been computed and displayed on the system.Meanwhile，the user can choose the optimal one.Guidance for the user is generated to the destination. Figure2 indicates the entire path from a place to E place.The green color places are the underground space place and the Just B＆W show the ground places.Now we can compute the shortest route between A-E through the Dijstra-algorithm（shown in algorithm 1）.As shown in algorithm 1，the shortest path is：0→2→7→13→19，that is，A→B2→C1→D1→E（2）3D viewpoint visionWeb GIS experiences the development from 2D system to 3D system，and the web GIS based on VRML is the most popular from of the 3D web GIS.3D web GISUses virtual reality technology and visualization technology to construct interactive 3D virtual scene on the Internet，meanwhile alsocan store，manage，analyze and display the geography information in the virtual environment.At present most of three dimensional Web GIS is based on VRML.Figure 3 is amodel of 3D web GIS（Wang，2008）.Based on the application of Web GIS and VR-based technology，using real three-dimensional simulation of underground space information systems，through the 3D panoramic imaging technology，Graphics Animation System Based on Object Modeling Technique，instant messaging SM interactive technology，shows a three-dimensional guidance through three-dimensional simulation performance of real world with diagrams.It displays3D viewpoint to users and more visualized than 2D video mode. 1.3 User inter faceThe 3DGS can be set in underground space as a production.It can hang up on column and easily show the guidance data in 3D view information.The system enables users to browse all the information by treating each viewpoint map and corresponding explanation in order.Figure 4 show the interface of a viewpoint generated using 3DGS.The users can input or search the name of destination on the block of interface，or use the microphone on application-embedded Voice device aside for disabled people.From menu，you can use any searching way you liked.Besides，you can get the information of latest news and hot issues including weather.The system prepares guiding contents with several links which guide user to walk along it，and the nearest one defined on the calculated routs is presented according to user current place.The guiding contents include text，photograph and audios，so that the user canunderstand the direction easily.Using the method of 3DGS，we have performed a simulation in a part of a city with 3D MAX，NAVISWORKS V3.6，and Vrcontext Walkinside3.5 software.They simulate all the scenes on ground and underground and get all the routes.According to the average walk speed，it computes the different times.In this section，through the case analysis，the performance of3DGS is shown.Figure5.and Figure6.Shows the plan of layout about a Sunway station including Exits underground and ground；Figure7.（a），（b），（c），show an example of the computing process simulation.We have assumed a user in the underground space and want to go to post office. Firstly，the users search the destination Jegidon Post office on the searching block.After computing，the 3DGS displays the underground subway line by scheme and many exits to the ground.Secondly，the ground and underground way are figured stly，all the routes distance and needed time which are calculated by the average walk speed have been displayed from short to long.And finally you have option to choose the optimal one.Schedule and photograph about the whole 3D routes of the journey are also displayed for selection options.The simulation results indicate that 3DGS can provide a useful guidance service in underground space.An obvious feature is its capability to compute and display the intelligent routes for user anywhere they want to ers can travel to unfamiliar place as well as familiar place using the 3DGS.The system might be beyond human capability to compute the realtime and provides the optimal routes even though there are unexpected changes depending on the traffic congestion or other unexpected schedules changed.Figure 3 shows the route guidance interface for interactive route selection，showing the automatic route recommendation after computing.Another feature is3D viewpointon vision.Different from existing 2D map in underground space，it provides a significant advantage.The device application-embedded Voice and Touch prompt functions assist the mobility and convenience for the disabled people with very simple setting.Sometimes limited by the true environment，further modification is needed for the perfection of the system.On the whole，even though it is just a simulation result，we can still get higher efficiency by using the 3DGS.In this paper，an intelligent guidance system 3DGS have been proposed，integrating GPS，GIS，3D visual technology etc.Through the case simulation of its implementation，feasibility and effectiveness are discussed.3DGS，considers the data route underground and ground information，and thus can guide users to destination quickly with the 3D viewpoint vision.At the same time，the application embedded voice and touch prompt system to support the service for disabled people.It is expected to achieve a significant effect and to play an important role on guidance system in underground space.A future work of 3DGS is to build basic prototype and text between different audiences.This system has some problems on technology andother issues，so it needs further improvement for its perfect use.It would provide other various services for underground space besides guidance system.There is still a long way to go in the future study to explore the potential for urban underground development.［1］Agnew，D.C.and Larson，K.M.（2007）.“Findin g the repeat times of the GPS constellation”.GPS Solutions（Springer）11（1）：71-76.［2］Bessho，M，Kobayashi，S，Koshizuka，N.＆Sakamura，K.（2007）A Pedestrian Navigation System using Multiple Space-Identifying Devices based on a Unique Identifier Framework.ICMLC.［3］Bessho，M，Kobayashi，S，Koshizuka，N.＆Sakamura，K.（2008a）A Space-identifying Ubiquitous Infrastructure and its Application for Tour-guiding Service.ACM New York，NY，USA.［4］Bessho，M，Kobayashi，S，Koshizuka，N.＆Sakamura，K.（2008b）uNavi：Implementation and Deployment of a Place-Based Pedestrian Navigation puter Software and Applications，PSAC＇08.32nd Annual IEEE International，1254-1259.［5］Chang，K.T.（1989）.“A comparison of techniques for calculating gradient and aspect from a gridded digital elevation m odel”.Bulleted list item International Journal of Geographical Information Science 3（4）：323-334.［6］Chang，K.T.（2008）.Introduction to Geographical Information Systems.New York：McGraw Hill.p.184.［7］Clarke，K.C.，（1986）.Advances in Geographic Information Systems，Computers，Environment and Urban Systems，Vol.10，pp.175-184.［8］Dijkstra，E.W.（1959）A Note on Two Problems in Connection with Graphs.Numerische Mathematik，1，269-271.［9］Li Guo，C，You Min，Z.，Zhengru，Y.＆You Shan，Y.（1991）Urban Underground Space Development and Civil Defence Construction-A Specia Problem＇s S.D.Model.System Dynamics，294-303.［10］Liu，X.，Corner，M.＆Shenoy，P.（2006）Ferret：Rfid Localization for Pervasive Multimedia.Lecture Notes in Computer Science，4206，422-440.［11］James R.Akerman（2006）Cartographies of Travel and Navigation，The university of Chicago press.［12］Massatt，Paul；Wayne Brady（2002）.“Optim izing performance through constellation management”.Crosslink：17-21.［13］Michael F.，（2010）.Twenty years of progress：GIScience in 2010.Journal Of Spatial Information Science Number 1 pp.3-20.［14］Michael Russell Rip，James M.Hasik（2002）.The Precision Revolution：GPS and the Future of Aerial Warfare.Naval Institute Press.p.65.［15］Nakayama，O.T Itoh，H Ueno（1989）Navigation system for automotive vehicle with automatic navigation start and navigation end point search and automatic route selection，US Patent.［16］Nowakowski C，P Green，O Tsimhoni（2003）Common automotive navigation system usability problems and a standard test protocol to identify them，Intelligent Transportation Society.［17］SKim，JH Kim（2002）Adaptive fuzzy-network-based C-measuremap-matching algorithm for car navigation system，Industrial Electronics，IEEE Transactions.［18］Wang，M.（2008）A 3DWeb GIS System Based on VRML andX3D.Genetic and Evolutionary Computing，2008.WGEC'08.Second International Conference on.。

用虚拟现实技术实现网页的3D效果
吕升
【期刊名称】《安徽科技》
【年(卷),期】2009(000)011
【摘要】@@ 虚拟现实(Virtual Reality,简称VR),是由美国VPL Research Inc公司的nier在1989年造的一个词,通常是指用头盔显示器和传感手套等一系列新型交互设备构造出的一种计算机软硬件环境,人们通过这些设施以自然的技能(如头的转动、身体的运动等)向计算机送人各种命令,并得到计算机对用户的视觉、听觉及触觉等多种感官的反馈.
【总页数】2页(P52-53)
【作者】吕升
【作者单位】安徽省基础测绘信息中心
【正文语种】中文
【相关文献】
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3.一种利用脸部识别技术实现3D效果自适应调节功能的方法 [J], 张奇;姚文兴;
4.网页数据库及网页的研制与实现 [J], 古新生;黎应禧;李志斌
5.电视网页中实现互联网页的效果 [J], 伍桦
因版权原因，仅展示原文概要，查看原文内容请购买。

毕业论文题目：虚拟现实引擎技术研究学生姓名：张玉伟学生学号：059080143系别：计算机与信息工程系专业：计算机科学与技术届别：2009届指导教师：杨星虚拟现实引擎技术研究 2目录前言 (3)1 概述 (4)1.1 虚拟现实技术的概述 (4)1.2 虚拟现实发展概况 (7)1.3 各国虚拟现实技术的研究及应用情况 (8)1.4 虚拟现实的技术的主要研究内容 (9)1.5 虚拟现实技术的意义 (9)2 虚拟现实引擎的结构及其关键技术 (9)2.1 虚拟现实系统的组成 (9)2.2 虚拟现实技术中引擎的构成 (11)2.3 虚拟现实引擎中的几个关键技术 (11)3 常用的可见性裁减算法 (16)3.1 遮挡裁减算法的分类 (16)3.2 物体空间的遮挡裁减算法 (17)3.3 图像空间的遮挡裁减算法 (21)4 可见性裁减的改进算法 (24)4.1 组织场景 (24)4.2 划分视点单元 (24)4.3 计算视点单元的可见性保守集PVS (26)4.4 改进遮挡算法的评价 (29)5 总结与展望 (29)5.1 总结 (29)5.2 展望 (30)致谢 (30)参考文献 (31)淮南师范学院2009届本科毕业论文 3虚拟现实引擎技术研究学生：张玉伟指导老师：杨星淮南师范学院计算机与信息工程系摘要：虚拟现实技术又称灵境技术，它是二十世纪末才兴起的一门崭新的综合性信息技术。

本文首先对虚拟现实（Virtual Reality）技术进行了概括性介绍，阐述了虚拟现实技术的基本概念、特征、发展、应用领域以及国内外的研究现状。

虚拟现实中的引擎是虚拟现实技术的核心之一，文中阐述了虚拟现实引擎的体系结构，及其相关的技术，如碰撞检测、可见性裁减、LOD 技术和光照模型。

本文对虚拟现实引擎的关键技术之一——可见性裁减问题做了研究，并提出了一种改进的遮挡裁减算法，此改进算法是将Durand 提出的扩展投影作为保守可见性预处理的算法与Greene 等人提出层次遮挡图和层次深度图的算法相结合，将遮挡板的扩展投影生成层次遮挡图来判断被遮挡物是否可见，同时保持了扩展算法的基本特性。

虚拟现实在网页设计中的应用虚拟现实（Virtual Reality，简称VR）是一种通过计算机技术模拟及创造出的三维交互式虚拟环境，它已经在许多领域展现了它的巨大潜力。

随着技术的不断进步，虚拟现实逐渐渗透到网页设计领域，为网页提供了更加丰富、沉浸式的用户体验。

本文将探讨虚拟现实在网页设计中的应用，以及其对用户体验和网页设计的影响。

一、虚拟现实技术在网页设计中的意义虚拟现实技术的出现为网页设计带来了新的可能性和挑战。

传统的网页设计主要依靠文字、图片和音频等元素来传达信息，但虚拟现实可以通过虚拟环境的构建，实现更加直观、沉浸式的用户体验。

它可以将用户带入到虚拟的世界中，使用户能够与设计内容进行更深入的互动和体验。

因此，虚拟现实技术在网页设计中具有重要的意义，可以提升用户对网页的参与度和互动性。

二、虚拟现实在网页设计中的应用案例1. 产品展示与体验：虚拟现实可以为产品展示提供更直观、真实的体验。

例如，一个建筑公司可以通过虚拟现实技术来呈现客户想要建造的房屋的全景图，让客户能够身临其境地感受到未来房屋的真实感。

此外，虚拟现实还可以用于汽车展示、家具展示等领域，为消费者提供更真实的产品感受。

2. 旅游与文化体验：通过虚拟现实技术，用户可以在网页上“亲临”各种景点和文化场所，探索世界各地的奇妙风景和文化遗产。

例如，一个旅游网站可以通过虚拟现实技术为用户提供身临其境的旅游体验，用户可以透过虚拟现实设备感受到当地的氛围，提前规划旅行路线。

3. 教育与培训：虚拟现实在教育和培训领域有着巨大的潜力。

通过虚拟现实技术，学生可以进行虚拟实验、参观历史遗迹、进行操作性训练等，提供更加真实、直观的学习体验。

这种形式的学习可以加强学科知识的理解和应用，提高学习效果。

4. 艺术与娱乐：虚拟现实可以为艺术家和娱乐行业带来更多创意和表现形式。

通过虚拟现实技术，艺术家可以创造出更加具有沉浸感的艺术作品，观众可以通过虚拟现实设备进一步体验这些作品。