Chapter Preview
TopBackground
For modeling building and geographic information, we have identified three axes of research and development (Figure 1). First, we have the BIM axis, which corresponds to the modeling of a building. Then, we have the GIS axis that represents geographic data and related tools. Finally, we have the contextual axis that represents the context related to a concept, through ontologies. In this multi-axes system, we can identify and place several solutions dedicated to the implementation of one or more fields. For example, CAD (Computer-Aided Design) software, which is used to draw buildings, can be positioned along the BIM axis. GIS-related applications, which can display 2D geo-referenced geometries, are located on the GIS axis. Then, semantic web languages, such as RDF (Resource Description Framework) and OWL (Web Ontology Language), which are used to model context, can be placed on the third axis, namely the context axis.
Figure 1. Axes for urban information modeling
Several approaches are available for 2D representation of building information, including 3D GIS, which can improve the buildings’ representation dimension of GIS. FM-CAD (Facility Management) from CAD editors provides some FM in order to ease the contextualization of BIM information. Similarly, we have BIM-GIS approaches from GIS editors that help modeling building information in geographic systems. Furthermore, we have solutions that allow more or less to deal with all three dimensions. These solutions are identified in Figure 1 and will be detailed in the next sections of this article.
In order to achieve interoperability among BIM and GIS, the use of standards is needed. For building information modeling, the most known and used standard is IFC (Industry Foundation Classes). As we can see in Figure 1, this approach is highly suitable for building information modeling, and allows to represent contextual and geographical data. Another standard worth mentioning is CityGML, an OGC (Open Geospatial Consortium) standard, which is specialized in dealing with geographical information, and allows some contextual information definition and building modeling. The third standard is a conceptual model for traditional & spatio-temporal applications called MADS (Modeling of Application with Spatial-temporal Data). It focuses on defining contextual mechanisms to create multiple representations for a given geographical context. This is done by defining stamps that correspond to a couple (resolution, point of view) and for which a given representation is valid. In the next sections, we will detail two of the above mentioned standards, namely IFC and CityGML.
Key Terms in this Chapter
Building Information Modelling (BIM): The term BIM has been presented recently as a demarcation of the next generation of Information Technologies (IT) and Computer-Aided Design (CAD) for buildings which focus on the production of drawings. BIM is the process of generating, storing, managing, exchanging, and sharing building information in an interoperable and reusable way.
Facility Management: The Facility Management is a set of processes that aims at managing spaces, infrastructures, people and organizations. It is used to anticipate and reduce inherent costs to the management of a building for example, and to add value to the core business of the client organization where possible. The urban FM extends this concept to the management of specific city elements, including geographic objects, networks, etc.
Urban Information Modeling: It is a semantic modeling framework that aimed at coupling GIS and BIM fields by the definition of contextual processes in order to integrate the business knowledge. It aims at modeling the knowledge of urban environment.
Geographic Information Systems (GIS): Is a system designed to capture, store, manipulate, analyze, manage, and present all types of geographical data. Geographical data are all kind of objects linked to a location. GIS are known to be effective in the management of large amount of data on large surface.
Ontology: Literature now generally agrees on the Gruber’s terms to define an ontology: explicit specification of a shared conceptualization of a domain. The domain is the world that the ontology describes. It can be a general domain or a more specific one. This description uses a vocabulary of concepts which is understandable and agreed by people of the domain; here is the meaning of “shared conceptualization.” The ontology can be implemented in several languages with a different level of formalization and expressivity, with no ambiguity that’s why ontology is an “explicit specification.”
CityGML: CityGML is an information model dedicated to the representation of sets of 3D urban objects. It is an open standard implemented as an application schema for the Geography Markup Language 3 (GML3), the extendible international standard for spatial data exchange issued by the Open Geospatial Consortium (OGC) and the ISO TC211.
IFC: The “Industrial Foundation Classes” (IFC) is an ISO standard that defines all components of a building in a civil engineering project. IFC includes object specifications, or classes, and provide a structure for data sharing among AEC applications.
Semantic Web: The term was coined by Tim Berners-Lee who defines the semantic Web as a web of data that can be processed directly and indirectly by machines. In other words, semantic Web is a mesh of information linked up in such a way so as to be easily processable by machines, on a global scale.