Modeling Cities and Landscapes in 3D with CityGML

Abstract

CityGML is the most important international standard used to model cities and landscapes in 3D with extensive semantics. Compared to BIM standards such as IFC, CityGML models are usually less detailed but they cover a much greater spatial extent. They are also available in any of five standardized levels of detail. CityGML serves as an exchange format and as a data source for visualizations, either in dedicated applications or in a web browser. It can also be used for a wide range of spatial analyses, such as visibility studies and solar potential. Ongoing research will improve the integration of BIM standards with CityGML, making improved data exchange possible throughout the life-cycle of urban and environmental processes. IntroductionMunicipalities and other governmental organizations are increasingly using 3D city and landscape models to maintain and plan the environment (see Fig. 11.1 for an example). These models contain 3D data about urban objects such as buildings, roads, and waterways, and the data is collected, maintained and used in applications for urban planning and environmental simulations. Examples of such applications are estimating the shadows cast by buildings and vegetation, simulations of floods and noise propagation, and predicting exposure of roof surfaces to sunlight to assess the potential of installing solar panels. An overview of applications of 3D city

STEP and IFC export to X3D

“…Instead a workflow involving semantic web technologies and the STL format is used to perform basic conversion to X3D. In the past decade, most of the work related to IFC and X3D involves the CityGML modeling language, used for modeling landscapes and cities [Ohori et al 2018]. Related papers use the CityGML as a pivotal data model to consolidate building and geographic data ( Figure 1).…”

“…2.4.2 Topology. Both STEP and IFC (up to version 4) rely on the ISO STEP 10303-42 integrated resource data for BRep topology and geometry representation [Ohori et al 2018]. The data model described in ISO 10303-42 introduces hundreds of classes (known as EXPRESS entities).…”

3d Geospatial Database Schema for Istanbul 3d City Model

“…Visualising CityGML over the web requires separating the geometric information from the semantic information in the commonly used 3D graphics formats like KML, COLLADA, glTF and 3D Tiles. It should be noted that when CityGML data is converted to those formats for 3D data visualisation over the Web, often the rich semantics of CityGML are lost (Arroyo et al, 2018). Therefore, in this study a Web services is utilised for attributes queries while 3D Tiles as 3D data visualisation as shown in Figure 6.…”

Integration Between Surface and Subsurface Spatial Objects for Developing Oman 3d Sdi Based on the Citygml Standard

“…On the other hand, the standard of CityGML mainly focuses on the spatial perspective, unlike the Industry Foundation Classes (IFC) standards and Building Information Modeling (BIM) (Arroyo Ohori et al, 2018;Biljecki et al, 2016Biljecki et al, , 2015aKensek, 2014). Hence, CityGML presents the most common (natural and human) spatial features that can be found in the cities and their surrounding with determining their geometric and semantic information.…”