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对城市地理标记语言(CityGML)的探讨 总被引:2,自引:0,他引:2
虚拟3D城市模型是三维城市GIS研究的基础。本文对CityGML1.0(City Geography Markup Language1.0,城市地理标记语言)的发展和核心技术进行了深入的研究,其主要内容包含了CityGML1.0的5层LOD模型、空间数据模型、CityGML模块、应用领域扩展等,还给出了基于CityGML1.0开发的系统实例,最后对CityGML的应用和发展进行了预测。 相似文献
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针对建筑信息模型(BIM)领域古建筑语义模型缺乏建筑物周围环境信息,不利于建筑模型与地形数据的集成、共享、空间分析等问题,该文提出了一种古建筑工业基础类(IFC)模型转换为城市地理标记语言(CityGML)扩展模型的方法。比较分析IFC和CityGML两种标准在建筑物模型实体语义和几何表达方面的差异,在对CityGML标准定义的建筑物模型进行语义扩展的基础上,从语义映射和几何转换两方面实现古建筑室内外几大类典型构件IFC模型到CityGML语义扩展模型的转换方法。实验结果证实了该文方法的有效性,该方法能够实现高精度、语义丰富的古建筑CityGML模型快速构建,有利于促进古建筑文化遗产数字化保护。 相似文献
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《武汉大学学报(信息科学版)》2020,(7)
分析了工业基础类(industry foundation classes,IFC)和城市地理标记语言(city geography markup language, CityGML)在几何表达、语义信息等方面的异同;以综合管廊为对象,建立IFC综合管廊模型转换为CityGML模型的流程和方法,进行语义提取、几何以及坐标系统的转换。通过六盘水城市综合管廊模型转换进行验证,结果表明,所建立的IFC管廊模型与CityGML管廊模型映射规则可实现IFC管廊模型向CityGML模型的转换,同时转换后的CityGML管廊模型包含由IFC模型提取的属性信息,可用于三维地理信息系统(three dimension geographical information system, 3DGIS)与建筑信息模型(building information modeling,BIM)的集成,有助于促进城市地下管廊全生命周期管理。 相似文献
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给出了利用CityGML模型自动构建三维封闭建筑体的基本框架和流程。充分利用已有的CityGML数据,分析其与三维封闭建筑体的语义关联和差别,奠定利用CityGML构建三维封闭建筑体的理论基础;从构建三维封闭建筑体所需几何数据出发,根据语义关联从CityGML中提取相应的几何数据,构建符合三维封闭建筑体要求的几何对象,满足三维立体规划和审批、核查的空间数据需要,进而弥补传统地籍数据采集方式的不足。 相似文献
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城市建筑物三维建模是虚拟3D城市建模的基础和重要组成部分。本文对基于CityGML1.0(City Geography Markup Language 1.0,城市地理标记语言)的城市建筑物三维建模技术进行了深入的研究,主要内容包含了CityGML1.0的简介、城市建筑物三维建模的方法和内容等,并给出了一个实际建模的例... 相似文献
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实景三维中国建设应满足自然资源管理与社会经济发展需求,因此需要对基础地理信息产品进行实体化改造,三维模型单体化正是实体化改造的关键环节。本文提出了一种基于CityGML的三维模型单体化方法,首先根据地物实体轮廓的二维矢量面提供的顶点坐标及高程信息,构造墙面、屋顶等多边形平面组成地物的简单三维表达,然后配合渲染到纹理技术(RTT)进行纹理贴图,基于CityGML为每个二维矢量面对应的地物重构出有语义、有LOD层级的三维模型。该方法能够高效地实现三维模型单体化,且成果模型容量小,可满足各种实景三维应用需求。 相似文献
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Christoph Blut Timothy Blut Jörg Blankenbach 《International Journal of Digital Earth》2019,12(1):25-42
CityGML, a semantic information model for digital/virtual city models has become quite popular in various scenarios. While the data format is still actively under development, it is already supported by different software solutions, especially GIS-based desktop applications. Mobile systems on the other hand are still neglected, even though the georeferenced objects of CityGML have many application fields, for example, in the currently popular area of location-based Augmented Reality. In this paper we present an independent multi-platform CityGML viewer, its architecture and specific implementation techniques that we use to realize and optimize the process of visualizing CityGML data for use in Augmented Reality. The main focus lies in improving the implementation on mobile devices, such as smartphones, and assessing its usability and performance in comparison to web-based approaches. Due to the constrained hardware resources of smartphones, it is a particular challenge to handle complex 3D objects and large virtual worlds as provided by CityGML, not only in terms of memory and storage space, but also with respect to mobile processing units and display sizes. 相似文献
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Recently a national 3D standard was established in the Netherlands as a CityGML Application Domain Extension (called IMGeo). In line with the Dutch practice of modeling geo‐information, the ADE is developed using a model driven approach. The classes are designed in UML and automatically mapped to GML schema. The current OGC CityGML specification does not provide rules or guidance on correctly modeling an ADE in UML. This article fills this gap by studying how CityGML can be extended for specific applications starting from the UML diagrams. Six alternatives for modeling ADEs in UML are introduced and compared. The optimal alternative is selected and applied to obtain the national 3D standard. The approach was extensively discussed with international experts, who were members of both SIG3D and other working groups. As a consequence the approach was adopted by the SIG3D, the Special Interest Group 3D which, among other things, work on the 3D standard CityGML in cooperation with OGC. Therefore the approach contains many issues that can be generalized and reused by future domain extensions of CityGML. To further support this, the article formulates a model‐driven framework to model CityGML ADEs. Open issues are described in the conclusions. 相似文献
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Automatic conversion of IFC datasets to geometrically and semantically correct CityGML LOD3 buildings 总被引:1,自引:0,他引:1
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Although the international standard CityGML has five levels of detail (LODs), the vast majority of available models are the coarse ones (up to LOD2, i.e. block‐shaped buildings with roofs). LOD3 and LOD4 models, which contain architectural details such as balconies, windows and rooms, rarely exist because, unlike coarser LODs, their construction requires several datasets that must be acquired with different technologies, and often extensive manual work is needed. In this article we investigate an alternative to obtaining CityGML LOD3 models: the automatic conversion from already existing architectural models (stored in the IFC format). Existing conversion algorithms mostly focus on the semantic mappings and convert all the geometries, which yields CityGML models having poor usability in practice (spatial analysis, for instance, is not possible). We present a conversion algorithm that accurately applies the correct semantics from IFC models and that constructs valid CityGML LOD3 buildings by performing a series of geometric operations in 3D. We have implemented our algorithm and we demonstrate its effectiveness with several real‐world datasets. We also propose specific improvements to both standards to foster their integration in the future. 相似文献
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Sameer Saran Kapil Oberai Parag Wate Amol Konde Arnab Dutta Kavisha Kumar A. Senthil Kumar 《Journal of the Indian Society of Remote Sensing》2018,46(6):957-972
Virtual 3D city models are increasingly being used to model the realms of the real world for utilization in a number of applications related to environmental simulations including, urban planning, mapping the energy characteristics of buildings, noise mapping, flood modelling, etc. Apart from geometric and appearance/textural information, these applications have a requirement for complex urban semantics. Currently, a number of 3D standards are available in CAD, BIM and GIS related domains for the storage, visualization and transfer of 3D geospatial datasets. Initially, the 3D data models (such as COLLADA, VRML, X3D, etc.) were purely graphical/geometrical in nature and mainly used for visualization purposes. With the inclusion of thematic modules in OGC CityGML, the integration of geometry and semantics in a single data model paved the way for better sharing of virtual 3D city models. In spite of the availability of a wide range of 3D data standards, there are certain differences with respect to geometry, topology, semantics, LODs, etc., which complicates the integration of 3D geodata from heterogeneous sources. This paper serves to highlights the need for the innovative solutions with respect to the urban environmental related simulations primarily based on the use of virtual 3D city models. Four use cases are studied in this context namely, (1) urban solar potential estimation using CityGML models, (2) simulation of traffic noise level mapped on building walls from the urban road segments, (3) CityGML based 3D data models interoperability, and (4) 3D indoor logistics and subsurface utilities. However, for modelling majority of use cases, CityGML does not provide explicit thematic representations but provides support for extending the CityGML schema using Application Domain Extensions. In a nutshell, the study explores the semantic modelling capabilities of the CityGML for the transformation of native 3D virtual city models to one satisfying capabilities like semantic information and support towards interoperability. 相似文献
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Arnab Dutta Sameer Saran A. Senthil Kumar 《Journal of the Indian Society of Remote Sensing》2017,45(6):993-1004
CityGML is an open data model for storage and exchange of 3D city models. It is categorised into thirteen thematic classes, i.e., buildings, tunnels, bridges, etc., lacking the other themes such as indoor routing and positioning. With the amplified use of indoor routing and positioning, the need for prerequisite notion of detailed semantic, as well as geometric information of the 3D building data has grown. We intend to extend the CityGML schema to add attributes of indoor features using the facility of Application Domain Extension (ADE) provided by the OGC CityGML 2.0. In this study, we aim to showcase the formation of Indoor Routing and Positioning ADE along with the process concerning its development, such as the 3D model design, network dataset creation, routing, positioning and Unified Modeling Language based ADE application schema generation. This research would help the users to easily store and exchange 3D city data on which they can perform routing and positioning inside the buildings with enhanced semantic and geometric properties. 相似文献