外文翻譯--應(yīng)用和解決方案兼容的三維可視化

1、<p><b>　　本科畢業(yè)設(shè)計</b></p><p><b>　　外文文獻(xiàn)及譯文</b></p><p>　　文獻(xiàn)、資料題目：Applications and Solutions for Interoperable 3d Geo-Visualization</p><p>　　文獻(xiàn)、資料來源： 網(wǎng)

2、絡(luò)</p><p>　　文獻(xiàn)、資料發(fā)表（出版）日期： 2006</p><p>　　院 （部）： </p><p>　　專 業(yè)： </p><p>　　班 級： </p><p>　　姓 名： </p><p>　　學(xué) 號： &

3、lt;/p><p>　　指導(dǎo)教師： </p><p>　　翻譯日期： </p><p><b>　　外文文獻(xiàn)：　</b></p><p>　　Applications and Solutions for Interoperable 3d Geo-Visualization</p><p&

4、gt;　　3D visualizations of spatial objects are employed in an increasing number of applications from the areas of (urban) planning, city marketing, tourism, and facility management. Further application fields could be ent

5、ered, if distributed spatial objects could be integrated on the fly into one 3d scene. We argue, that this integration can only be successful (and in some cases only be possible) if it does not mean to copy and concentra

6、te all data into one monolithic system. In this article we sketch</p><p>　　1. INTRODUCTION</p><p>　　3D city and landscape models reveal a high information potential for a variety of application

7、fields in the private and public sector. Besides the well-known applications in the fields of architecture,urban and transport planning, surveying and mobile telecommunication, 3d models become increasingly important in

8、the fields of city and regional marketing (e.g. representation of regions,municipalities, companies and Football World Cup locations), tourism (recreation, culture), telematics (pedestri</p><p>　　Most applic

9、ations typically need various geoinformation from different data providers. E.g. an architecture firm requires for the planning of a new shopping mall digital 3d geoinformation in</p><p>　　terms of a small s

10、caled and low detailed city model covering the whole planning area, which will</p><p>　　support the identification of appropriate locations. The 3d objects also have to be related to socioeconomical 2d geoin

11、formation. When the appropriate location has been found, detailed architectural resp. building models with detailed texturing are necessary for the target area in order to be able to demonstrate the integration of the sh

12、opping mall with its environment by 3d visualization.Difficulties arise, because spatial data sets are not only scattered over different public and private data </p><p>　　At large, the widespread and sustain

13、able use of 3d geoinformation in the mentioned application fields is hindered by high pricing, limited data availability, missing 3d analysis instruments, diversity of formats and processing systems, and insufficient acc

14、ess mechanisms. Above, data actuality and quality of 3d models often is low, because in many cases 3d city models have been acquired for specific projects only and were not updated afterwards.</p><p>　　Howev

15、er, users require immediate data access, means for the interoperable integration of different 3d geoinformation in different levels of detail, tools for 3d analysis and further data processing (based on data storage usin

16、g databases, general purpose 3d GIS with functionalities like visibility analyses etc.) as well as solutions for interactive visualization and presentation. Furthermore, aspects of model integrity, security, data updatin

17、g (and its costs), 2d-3d-integration, real time visuali</p><p>　　It is the aim of the initiative Geo Data Infrastructure North Rhine-Westphalia (GDI NRW) to</p><p>　　improve the availability, us

18、e and distribution of spatial data and thereby enable the geoinformation market in NRW and beyond. The GDI NRW realizes an open network bringing together geoinformation producers, value adders, brokers and users. By the

19、application of web service technology the spatial data from public and private sources can be registered, queried and visualized in an interoperable way (Bernard et al. 2003). The Initiative GDI NRW was founded in 1999 a

20、s a public private partnership b</p><p>　　To overcome the above mentioned specific problems of 3d data handling and visualization, the Special Interest Group 3D (SIG 3D) has been founded as a working group i

21、n the GDI NRW. For more than a year it is working on the development of user-oriented concepts for the interoperable integration of different distributed 3d spatial data resources of public and private providers. The gen

22、eral idea is to avoid central data storages and monolithic, proprietary applications. Instead, 3d spatial data shou</p><p>　　2. DEMANDS AND CHANCES FOR DISTRIBUTED 3D GEOVISUALIZATION</p><p>　　I

23、n the feasibility study, Virtual Regions in the Rhine-Ruhr area 2006”which has been carried out by CeGi GmbH until ”July 2003 on behalf of the state government of North Rhine-Westphalia,Germany, current and future applic

24、ation fields for interoperable 3d GIS and 3d visualization have been identified and rated. The investigations are based on numerous and comprehensive interviews with experts coming from business, administration, organisa

25、tions and research institutions focused on their role as a </p><p>　　2.1. Overall chances of distributed 3D data resources</p><p>　　According to the results of the feasibility study, an interope

26、rable system of distributed 3d data resources provides the following chances and advantages (CeGi 2003b):</p><p>　　2.1.1. Interoperability and compatibility</p><p>　　By ensuring interoperability

27、 of data formats and systems the users can access arbitrary 3d spatial data sources in a homogeneous way. It allows the application of the same analysis and visualization tools for different data sets. The retrieval of a

28、ppropriate geoinformation is supported by a metadata information system, which currently is developed for NRW. Although there already exist numerous international standards of the OpenGIS Consortium for data access and v

29、isualization (OGC 2003),some tec</p><p>　　2.1.2. Multiple use and sustainability</p><p>　　Interoperability and compatibility offer multiple usage of geoinformation as well as the creation of add

30、ed value and more convenient data updating, and thereby assure the sustainability and quality of 3d data resources. In many cases the acquisition of 3d geoinformation has been project-based (especially in projects that w

31、ere focused on 3d visualization only), which means that database storage, further data processing, re-use and data updating are not assured. Mostly, a one-time investment is do</p><p>　　2.1.3. Improvement of

32、 work flow and efficiency</p><p>　　The sustainable use of distributed 3d spatial data resources induces synergy effects by avoiding repeated work due to redundant data storage and analyses. Thus it brings fa

33、cilitation of work and improvement of efficiency. This includes the shortening of internal processes by providing fast data access (e.g. improved use of geoinformation in municipal administrations), improved visualizatio

34、n of urban planning projects, more transparent and curtated planning procedures, improved citizen participat</p><p>　　2.1.4. Chances of refinancing</p><p>　　Interoperable 3d geoinformation syste

35、ms show market, economisation and refinancing potentials. In the long run, only such applications running on a spatial data infrastructure can be successful, which reveal real market potentials, i.e. there is a strong de

36、mand on the market by users, or a specific need and long-lasting sale possibilities based on the applications’direct and indirect economisation and refinancing possibilities.</p><p>　　2.1.5. Public Private P

37、artnership</p><p>　　The complex technical, socio-economical and administrative conditions concerning the sustainable realization of the spatial data infrastructure in NRW require the participation of economy

38、,administration and academia (Public Private Partnerships). Only by collaboration and concerted decision making the existing deficiencies and limitations can be overcome.</p><p>　　2.2. Special chances of 3D

39、visualization</p><p>　　3d visualization reveals chances and advantages in the following respect:</p><p>　?。?）.It provides graphical presentations of and insights into states, procedures and proc

40、esses.</p><p>　?。?）.It supports analysis, decision making, management and planning and thereby improves work</p><p>　　flows and efficiency in different application fields.</p><p>　　

41、Most technological issues concerning 3d visualization are clear. There already exist various</p><p>　　solutions for 3d visualization. Whereas most of them are proprietary applications, their technological ba

42、sic concepts can be transferred when developing standards for the visualization, access and retrieval of distributed 3d data resources.</p><p>　　2.3. Application fields for 3d geo-visualization</p>&l

43、t;p>　　In the following the chances and advantages of distributed 3d data and visualization systems will be highlighted for the different application fields. The analytical and management support of 3d visualizations i

44、n the government and business sector takes an important role. 3d applications in the customer sector, like e.g. location based services on mobile phones and personal digital assistants (PDAs), are presently only of margi

45、nal importance. Generally, multiple-shift usage as well as economizat</p><p>　　In the sector of site and city marketing, tourism and business development, 3d visualization enables the presentation of busines

46、s locations, municipalities, touristic sites and industrial areas.These presentations serve e.g. for captive marketing activities, municipal advertisement of recreation and tourism locations, evaluation of aesthetical as

47、pects of city planning as well as for the marketing of trade areas and industrial buildings. Marketing for sporting events as well as recreation infrast</p><p>　　Especially in the sector of event and buildin

48、g management, 3d visualization supports the management aspect, e.g. concerning the facility management of industrial buildings, event locations and public establishments. Site models are used for calculations of area- an

49、d volume-oriented services like commercial cleaning, seating, assurance value determination or fire fighting activities as well as for security surveillance concerning electricity and gas systems, partially in conjunctio

50、n with external</p><p>　　In the sector of city, traffic and regional planning, the 3d vizualisation of distributed 3d data</p><p>　　resources facilitates the improvement of plan visualization as

51、 well as the support of decision</p><p>　　making, analyses and planning activities. It comprises e.g. the visualization of building structures,</p><p>　　civil engineering, and visibility applica

52、tions concerning urban landuse planning and building</p><p>　　permission procedures as well as monument protection and greenspace planning (tree and</p><p>　　greenspace register). 3d visualizati

53、on contributes in this sector especially to the improvement of</p><p>　　work flows and efficiency, first of all in the context of municipal administrations, e.g. by process</p><p>　　simplificati

54、on, higher degrees of citizen participation in planning procedures, more transparent</p><p>　　decision making in planning processes, more reality-like presentations of planning alternatives</p><p&

55、gt;　　(analysis of impacts), early rejection of non-realistic alternatives or well-founded support of council decisions. An active participation of citizens includes e.g. the examination of planning alternatives over the

56、internet by a standard web browser integrating annotation and decision possibilities. 3d GIS, high data actuality and updating as well as an on-demand access to distributed data resources are essential in this applicatio

57、n field.</p><p>　　Concerning the sector of traffic and transport, 3d visualization is employed in telematic applications like pedestrian and car navigation systems. Currently, manufacturers of navigation sys

58、tems are acquiring 3d spatial data for the most important and famous landmarks in Europe which will be integrated in their navigation systems in the future. The sector of traffic and transport relies on high availability

59、 and interoperability of continuously updated, georeferenced 3d data.</p><p>　　In the environmental sector 3d visualization is used especially for the presentation of analyses results. Dispersion models are

60、employed for analyses of noise characteristics, air flows and emission dispersions. 3d visualization is also used for view determinations in the context of urban planning (new building projects, shadow and lighting effec

61、ts). Presentations of water bodies in flood protection simulations and aspects of coastal and mudflat protection (waterway and port protection through m</p><p>　　2.4. Scenarios for integrated 3d visualizatio

62、n</p><p>　　If 3d spatial data are stored decentralized at different places, the totally covered space is</p><p>　　fragmented. In his work on the consistency of distributed 2d spatial data resour

63、ces Laurini</p><p>　　distinguishes between zonal and layer fragmentation (Laurini 1998). For 3d data zonal</p><p>　　fragmentation means a partitioning of the modeled 3d space where different res

64、ources contain</p><p>　　spatial data of different regions resp. subspaces. Layer fragmentation describes instead situations</p><p>　　where distributed data sets represent different aspects / ele

65、ments of the same space (and in 2d maps are kept in different layers). According to this distinction two scenarios for integrated 3d geovisualization for distributed 3d city and region models can be developed.</p>

66、<p>　　The so-called mosaic scenario manages the 3d visualization of large areas. 3d city and site models from different sources are embedded at the time of presentation into a regional model and are visualized toge

67、ther. This scenario is especially suited for building region portals, where area-covering presentation is needed on the one hand, and possibilities for detailed examination of locations of interest should be given on the

68、 other hand(“zoom in to the level of 3d building models”)</p><p>　　In the hierarchy scenario visualization is focused on a specific area for which different providers at different locations contribute 3d spa

69、tial data. A typical application would be the integrated presentation of a 3d city model consisting of spatial objects with different degrees of detail. For example, while building models may be delivered by the city’s l

70、and registry office and the digital terrain model is retrieved from the state’s survey office, company B provides vegetation and other 3d ob</p><p>　　Applications may also combine aspects from both scenarios

71、. However, these applications always</p><p>　　have in common that spatial data is kept at their sources by their owners who provide online access by standardized interfaces. The advantage is that spatial dat

72、a have not to be copied into a central system, but will be retrieved at the time of presentation from the different providers. By avoiding redundant data storage it is ensured that every 3d visualization is based on the

73、latest data. Above, this approach allows exact accounting of the 3d spatial objects that are actually used in presented</p><p>　　3. INTEROPERABLE 3D GEOVISUALIZATION OVER THE WWW</p><p>　　After

74、the description of the different application scenarios the technical issues regarding their realization have to be discussed. Several municipalities and companies nowadays already have built up virtual 3d city models. Si

75、nce none of the commercially available geoinformation systems provide full support for the representation, storage, analysis, and visualization of 3d spatial objects yet (see Zlatanova 2002 et al.), existing 3d city mode

76、ls typically are stored and maintained in CAD systems,</p><p>　　3.1. Geo-visualization using web services</p><p>　　Concerning the presentation of spatial data the OpenGIS Consortium follows the

77、line of (Haber and McNabb 1990). They introduced the concept of the visualization pipeline, which describes visualization as a multi-level process starting from non-graphical object representations stored in a repository

78、 (e.g. a database) and ending with the final presentation of graphical entities on a display device. In the OpenGIS framework presentation of spatial data is discussed under the term portrayal and is r</p><p&g

79、t;　　The components of the portrayal pipeline have not to reside on the same system; they can be distributed over the internet. However, in client-server applications the lower level components are typically realized by o

80、ne or more servers while the remaining visualization tasks are handled by the client. According to their complexity clients are classified into thick, medium, and thin clients. Thick clients communicate on the feature le

81、vel with the server. The advantage is that the client is free to</p><p>　　The decision which client model is appropriate for what application depends on the specific application scenario on the one hand and

82、the availability of appropriate data and services on the other hand. If 3d visualization plays only a minor role, for example, when a 3d view of a sports rena has to be shown in an online ticket service application, a th

83、in client should be used. In such scenarios it should be avoided that users have to install a plug-in in order to be able to use the system. Otherw</p><p>　　3.2. Using OpenGIS data web services for 3D visual

84、ization</p><p>　　The OGC has specified a number of web services (OWS) for the work with spatial data. These services are categorized into data services, portrayal services, transformation services, and regis

85、try services. For the realization of 3d geo-visualization only the data services and the portrayal services will be considered in the following. Data services provide access to the spatial data. In this application the d

86、ifferent objects like terrain, vegetation, water bodies, and the road network are visualiz</p><p>　　3.3. Specific 3D visualization services</p><p>　　In contrast to data services the portrayal se

87、rvices deliver graphical representations of the spatial data and not the spatial data themselves. They typically cover the rendering and mapping components of the portrayal pipeline. The selection of the objects to be pr

88、esented may also be part of a portrayal service. Whereas for 2d visualization the Web Map Service (WMS) is already established 3d portrayal services are still at the beginning. With the proposal of the Web Terrain Servic

89、e (WTS) </p><p>　　the OGC is making a first step in the direction of 3d visualization. The WTS is described as an extension to the WMS that allows to show maps from non-standard viewing angles, i.e. not only

90、 90° from above but also providing perspectively distorted views. Furthermore, 2d maps or</p><p>　　orthophotos can be draped over digital terrain models providing textured 2.5d views (cf. Singh</p>

91、;<p>　　2001). The draft specification of the WTS considers only (raster) images for output media. It is</p><p>　　currently not specified which input data types can be used, from which sources they may

92、 be</p><p>　　obtained, and how the WTS should combine them in order to render the images. Although the WTS specification still has the status of an OGC discussion paper, a first implementation is already ava

93、ilable in the framework of the Java based open source system Deegree (Deegree 2003). </p><p>　　To bridge the gap between 3d visualization using OGC data services (and thick clients) and the portrayal service

94、 WTS (and thin clients) the SIG 3d of the GDI NRW is working on the</p><p>　　specification of a new dedicated 3d portrayal service called Web 3D Service (W3DS). It is based on the proposal of the WTS and ext

95、ends it by the explicit consideration of 3d features and the output of 3d display elements. The W3DS is capable of generating output both on the image and the display element level of the portrayal pipeline. This way, a

96、medium client can fetch 3d display elements from different W3DS which then are merged and shown simultaneously.</p><p>　　The mandatory output data format of the W3DS is VRML97 (see VRML97 1997). GeoVRML and

97、X3D may also be delivered as optional resp. future data formats (see Reddy et al. 2000). Above, numerous (and in many cases free) 3d browsers and web brower plug-ins for VRML97 are available. Furthermore, most commercial

98、ly available GIS, 3d CAD and 3d visualization systems offer VRML export and import functionalities. These systems can be made interoperable on the visualization level, if specific W3DS adapters </p><p>　　4.