Chair of Methods of Geoinformation Science 4th of March, 2008 CityGML - Modelling our environment Alexandra Stadler, Thomas H. Kolbe Technische Universität Berlin Institute for Geodesy and Geoinformation Science Chair of Methods of Geoinformation Science

Alexandra Stadler, Thomas H. Kolbe: CityGML – Modelling our environment 2 Chair of Methods of Geoinformation Science 4th of March, 2008 Content  Introduction to CityGML  General characteristics  Modularisation  Coherence of semantics and geometry  Multi-Scale modelling  Terrain Intersection Curve (TIC)  External references  Appearances  Application Domain Extensions (ADE)  Implementation, Conversion, Viewer  Target application areas  Noise immision mapping  Homeland Security  CityGML code example: Building in LOD 3

Alexandra Stadler, Thomas H. Kolbe: CityGML – Modelling our environment 3 Chair of Methods of Geoinformation Science 4th of March, 2008 Content  Introduction to CityGML  General characteristics  Modularisation  Coherence of semantics and geometry  Multi-Scale modelling  Terrain Intersection Curve (TIC)  External references  Appearances  Application Domain Extensions (ADE)  Implementation, Conversion, Viewer  Target application areas  Noise immision mapping  Homeland Security  CityGML code example: Building in LOD 3

Alexandra Stadler, Thomas H. Kolbe: CityGML – Modelling our environment 4 Chair of Methods of Geoinformation Science 4th of March, 2008  Ongoing virtualisation of our environment  Semantic models of all relevant objects in urban space  Base models include most important feature classes and attributes  Objects may have several geometrical representations  Spatial reference links data of different disciplines, since they refer to the same physical space  Initiatives  Inspire  EuroSDR Motivation

Alexandra Stadler, Thomas H. Kolbe: CityGML – Modelling our environment 5 Chair of Methods of Geoinformation Science 4th of March, 2008 Standards are the key… …to the integration of (3d geo) data of different data sources Application Data source A Data source B

Alexandra Stadler, Thomas H. Kolbe: CityGML – Modelling our environment 6 Chair of Methods of Geoinformation Science 4th of March, 2008 Never heard about CityGML – what‘s that? Content  Modelling of all relevant parts of the virtual city according to their semantics, geometry, topology and appearance  GML 3 application schema (XML based)  Data model and exchange format for virtual 3d city models History  Developed since 2002 by the Special Interest Group 3d (NorthRhine Westphalia, Germany)  Members from >70 companies, municiplaities and research institutions lead managed by  Prof. Thomas Kolbe (IGG TU Berlin)  Dr. Gerhard Gröger (IGG Uni Bonn)

Alexandra Stadler, Thomas H. Kolbe: CityGML – Modelling our environment 7 Chair of Methods of Geoinformation Science 4th of March, 2008 CityGML‘s way to become an OGC standard CityGML OGC Best Practices Paper CityGML (Proposal) OGC Request for Comments CityGML OGC Discussion Paper CityGML OGC Implementation Specification (after final OGC TC vote) coming soon >>>>>>  International Standard

Alexandra Stadler, Thomas H. Kolbe: CityGML – Modelling our environment 8 Chair of Methods of Geoinformation Science 4th of March, 2008 Content  Introduction to CityGML  General characteristics  Modularisation  Coherence of semantics and geometry  Multi-Scale modelling  Terrain Intersection Curve (TIC)  External references  Appearances  Application Domain Extensions (ADE)  Implementation, Conversion, Viewer  Target application areas  Noise immision mapping  Homeland Security  CityGML code example: Building in LOD 3

Alexandra Stadler, Thomas H. Kolbe: CityGML – Modelling our environment 9 Chair of Methods of Geoinformation Science 4th of March, 2008 Modularisation CityGML consists of  the core module  several extension modules  vertical subdivision

Alexandra Stadler, Thomas H. Kolbe: CityGML – Modelling our environment 10 Chair of Methods of Geoinformation Science 4th of March, 2008 Coherence of semantics and geometry … Semantic object e.g. Building Corresponding geometry e.g. Solid …  Use of Boundary Representation (B-Rep) for geometry modelling  Explicit relations between semantic objects and their geometrical representations * *

Alexandra Stadler, Thomas H. Kolbe: CityGML – Modelling our environment 11 Chair of Methods of Geoinformation Science 4th of March, 2008 Geometry Semantics KML: No semantics, only (unstructured) geometry CityGML vs. KML CityGML: (Up to) Complex objects with structured geometry Semantics Geometry

Alexandra Stadler, Thomas H. Kolbe: CityGML – Modelling our environment 12 Chair of Methods of Geoinformation Science 4th of March, 2008 „Availability“ of semantics  Geometric entities know WHAT they are  Semantic entities know WHERE they are and what their spatial extents are

Alexandra Stadler, Thomas H. Kolbe: CityGML – Modelling our environment 13 Chair of Methods of Geoinformation Science 4th of March, 2008 Multi-scale modelling LOD 4 – Interior model „Walkable“ architectural models LOD 3 – City / Site model Detailed architectural model LOD 2 – City / Site model Explicit roof structures LOD 1 – City / Site model „Block model“ without roof structures LOD 0 – Regional model 2.5d Digital Terrain Model

Alexandra Stadler, Thomas H. Kolbe: CityGML – Modelling our environment 14 Chair of Methods of Geoinformation Science 4th of March, 2008 Terrain intersection curve  Defines the intersection of an object with the terrain  Applicable to  Building  CityFurniture  GenericCityObject  Implicitly: WaterBody, Transportation, LandUse

Alexandra Stadler, Thomas H. Kolbe: CityGML – Modelling our environment 15 Chair of Methods of Geoinformation Science 4th of March, 2008 External references Objects may  Refer to their original data sources  Refer to other external data sources containing additional data, e.g.  Building: Link to cadastre, information about owners  Door: Link to facility management systems  Antenna: Link to mobile communication databases

Alexandra Stadler, Thomas H. Kolbe: CityGML – Modelling our environment 16 Chair of Methods of Geoinformation Science 4th of March, 2008 Appearances  Materials (similar to X3D)  Textures  Standard textures (explicit texture coordinates)  Aerial images (georeferenced)  Projected photos  Multiple appearances (themes) per object

Alexandra Stadler, Thomas H. Kolbe: CityGML – Modelling our environment 17 Chair of Methods of Geoinformation Science 4th of March, 2008 Application Domain Extensions (ADE) = Specific application schemata (e.g., noise immission mapping) Extend CityGML model by  Additional feature classes  Additional attributes  Additional relations Design remarks:  CityGML+ADE files remain valid CityGML  „Pure“ CityGML readers ignore ADE (unknown namespace!)  Accessible XSD document required for each ADE  Used for validating corresponding CityGML files

Alexandra Stadler, Thomas H. Kolbe: CityGML – Modelling our environment 18 Chair of Methods of Geoinformation Science 4th of March, 2008 Content  Introduction to CityGML  General characteristics  Modularisation  Coherence of semantics and geometry  Multi-Scale modelling  Terrain Intersection Curve (TIC)  External references  Appearances  Application Domain Extensions (ADE)  Implementation, Conversion, Viewer  Target application areas  Noise immision mapping  Homeland Security  CityGML code example: Building in LOD 3

Alexandra Stadler, Thomas H. Kolbe: CityGML – Modelling our environment 19 Chair of Methods of Geoinformation Science 4th of March, 2008 German cities modelled in CityGML 3d city models based on CityGML  Berlin  Dresden  Stuttgart  Bonn  Cologne  Frankfurt/Main  …  whole NRW in LOD 1 Planned for  Karlsruhe  … Berlin (GoogleEarth) Stuttgart (SupportGIS)

Alexandra Stadler, Thomas H. Kolbe: CityGML – Modelling our environment 20 Chair of Methods of Geoinformation Science 4th of March, 2008 Implementation Growing awareness of CityGML (particularily in the US) Discussions with  Web 3D Consortium  CTO GoogleEarth  International Alliance for Interoperability (IFC-Standard) Selected implementations:  Oracle 11G Spatial  Bentley Microstation, Onuma Planning System (CAAD)  Feature Manipulation Engine (FME)  Snowflake Software, lat/lon (Web Feature Service)  CPA SupportGIS (3d GIS-System)

Alexandra Stadler, Thomas H. Kolbe: CityGML – Modelling our environment 21 Chair of Methods of Geoinformation Science 4th of March, 2008 Conversion  CityGML  FME (con terra)  IFC  CityGML (Forschungszentrum Karlsruhe) original IFC modelCityGML LOD 1CityGML LOD 2CityGML LOD 3CityGML LOD 4

Alexandra Stadler, Thomas H. Kolbe: CityGML – Modelling our environment 22 Chair of Methods of Geoinformation Science 4th of March, 2008 Viewer  LandXPlorer (C++)  3D Geo, Potsdam  Hasso-Plattner-Institute (University of Potsdam)  Aristoteles 3D-Viewer (Java)  IGG, University of Bonn

Alexandra Stadler, Thomas H. Kolbe: CityGML – Modelling our environment 23 Chair of Methods of Geoinformation Science 4th of March, 2008 Content  Introduction to CityGML  General characteristics  Modularisation  Coherence of semantics and geometry  Multi-Scale modelling  Terrain Intersection Curve (TIC)  External references  Appearances  Application Domain Extensions (ADE)  Implementation, Conversion, Viewer  Target application areas  Noise immision mapping  Homeland Security  CityGML code example: Building in LOD 3

Alexandra Stadler, Thomas H. Kolbe: CityGML – Modelling our environment 24 Chair of Methods of Geoinformation Science 4th of March, 2008 Target application areas

Alexandra Stadler, Thomas H. Kolbe: CityGML – Modelling our environment 25 Chair of Methods of Geoinformation Science 4th of March, 2008 Application scenario 1: Noise immision mapping EU Directive: Minimisation of noise immissions  Calculation of noise immission maps for whole North Rhine-Westphalia  Data provision and exchange via CityGML using web services (WFS, WCS, WMS):  8.4 million 3d buildings in LOD 1  3d street network in LOD 0, with additional noise related attributes  3d rail network in LOD 0  3d noise barriers in LOD 1  Digital terrain model (10 meter resolution)

Alexandra Stadler, Thomas H. Kolbe: CityGML – Modelling our environment 26 Chair of Methods of Geoinformation Science 4th of March, 2008 Application scenario 1: Noise immision mapping Noise immsion maps reported to EU (via WMS service) Noise immision simulation 3d geodata in CityGML as input for the calculaion of noise immision maps

Alexandra Stadler, Thomas H. Kolbe: CityGML – Modelling our environment 27 Chair of Methods of Geoinformation Science 4th of March, 2008 Application scenario 2: Homeland security Testbed OWS-4 of the Open Geospatial Consortium (OGC)  Setting: Explosion of a „dirty bomb“ in the New York harbour  Task: Support the planning committee in the construction of an emergency hospital  Find the appropriate location  Identify best fitting existing building (size, room layout, air conditioning for decontaminations, etc.)  Thematic queries & visual inspections  Link different web services and client applications  Data formats: CityGML and IFC

Alexandra Stadler, Thomas H. Kolbe: CityGML – Modelling our environment 28 Chair of Methods of Geoinformation Science 4th of March, 2008 Application scenario 2: Homeland Security  CityGML building visualised using LandExplorer  from outside (left)  room-based representation of the security level (right)

Alexandra Stadler, Thomas H. Kolbe: CityGML – Modelling our environment 29 Chair of Methods of Geoinformation Science 4th of March, Application scenario 2: Homeland Security

Alexandra Stadler, Thomas H. Kolbe: CityGML – Modelling our environment 30 Chair of Methods of Geoinformation Science 4th of March, 2008 Content  Introduction to CityGML  General characteristics  Modularisation  Coherence of semantics and geometry  Multi-Scale modelling  Terrain Intersection Curve (TIC)  External references  Appearances  Application Domain Extensions (ADE)  Implementation, Conversion, Viewer  Target application areas  Noise immision mapping  Homeland Security  CityGML code example: Building in LOD 3

Alexandra Stadler, Thomas H. Kolbe: CityGML – Modelling our environment 31 Chair of Methods of Geoinformation Science 4th of March, 2008 CityGML code example: Building in LOD 3 <CityModel xmlns=" xmlns:bldg=" xmlns:gml=" xmlns:xlink=" xmlns:xsi=" xsi:schemaLocation=" This file contains four buildings which are automatically converted from IFC models. This listing only shows an excerpt. The full dataset can be downloaded from (example dataset for “four buildings in LOD3”) IFC_Building_Variant … Building in LOD 3 Building-ADT urn:ifc:oid:0deJpNQ05BvwV03c405oVp

Alexandra Stadler, Thomas H. Kolbe: CityGML – Modelling our environment 32 Chair of Methods of Geoinformation Science 4th of March, 2008 CityGML code example: Building in LOD 3 VR-Systeme/html/Download/ urn:ifc:oid:3CPSkwS7f9QRfhfr5gf7dq …

Alexandra Stadler, Thomas H. Kolbe: CityGML – Modelling our environment 33 Chair of Methods of Geoinformation Science 4th of March, 2008 CityGML code example: Building in LOD 3 VR-Systeme/html/Download/ urn:ifc:oid:2es$8LnAD9UxRIGzY8UaVK …

Alexandra Stadler, Thomas H. Kolbe: CityGML – Modelling our environment 34 Chair of Methods of Geoinformation Science 4th of March, 2008 CityGML code example: Building in LOD 3 german/projekte/VR-Systeme/html/Download/ urn:ifc:oid:3VkZRUoa97GgMdD342zHck … …

Alexandra Stadler, Thomas H. Kolbe: CityGML – Modelling our environment 35 Chair of Methods of Geoinformation Science 4th of March, 2008 Search the web for further examples… e.g.

Alexandra Stadler, Thomas H. Kolbe: CityGML – Modelling our environment 36 Chair of Methods of Geoinformation Science 4th of March, 2008 Search the web for further examples… e.g.

Alexandra Stadler, Thomas H. Kolbe: CityGML – Modelling our environment 37 Chair of Methods of Geoinformation Science 4th of March, 2008 Thank you… One thing we would really like to know: What do YOU think about CityGML? CONTACT INFORMATION Prof. Dr. Thomas H. Kolbe, Claus Nagel, Alexandra Stadler { kolbe | nagel | stadler igg.tu-berlin.de Technische Universität Berlin Institute for Geodesy and Geoinformation Science Chair of Methods of Geoinformation Science