The remainder of this chapter is organized as follows: Sect. 2 provides an
overview of the related 3D models which include CityGML (City Geography
Markup Language), IFC (Industry Foundation Classes), and UBM (The
Unified Building Model) focused on building models. Section 3 presents
the main concept of CityGML Indoor ADE, and feature models of indoor
space and indoor facilities. To validate the proposed data model, experimental
implementations are performed in Sect. 4 . Finally, the conclusion and future
works are addressed.
2 3D Building Models
Recent efforts have proposed several spatial data models to represent indoor
space (ISO 1910 ; OGC 2012 ; Isikdag et al. 2013 ). In the following, we will
examine CityGML, IFC, and UBM. CityGML as a standard of Open Geospatial
Consortium is an open data model to storage and exchange virtual 3D city
model based on XML. IFC is an international standard for data exchange of
IAI (International Alliance for Interoperability). The data model supports inter-
operability with Architecture, Engineering, and Construction. UBM is a unified
building model which is proposed for data integrations between the CityGML
and IFC models.
CityGML (OGC 2008 ) is a data format for exchange and storage of virtual
3D city model, which is XML-based data model as a representative open data
model. The purpose of CityGML development is to define common entities,
attributes, and relations of 3D city models that can be shared with other applica-
tions. CityGML refers to ISO 19100 series and the other documents related to
XML standards. CityGML consists of a geometry model and a thematic model.
Geometry model defines geographical and topological attributes of spatial objects
in 3D city model.
The building model of CityGML represents thematic and spatial aspects of
the building features within specific levels of detail, through LoD0 to LoD4
(OGC 2008 ; Kolbe 2009 ). LoD0 is the lowest level of detail, which describes
only the building footprint by horizontal surfaces. LoD1 represents geometry
of the outer shell. LoD2 represents exterior shell and the semantic components.
BoundarySurface , BuildingInstallation are modeled in LoD2. BoundarySurface has
several thematic classes representing the surface classified boundary, RoofSurface ,
WallSurface , GoundSurface are defined in LoD2 (Mohamed and Anders 2010 ) and
BuildingInstallation is the outer elements of the building. LoD3 provides the build-
ing in the higher level than LoD2 describing openings like windows and doors.