1 / 31

Understanding CityGML: An International 3D Model Standard

Explore CityGML, a standard for virtual 3D city models with detailed semantics, geometries, and appearances, developed since 2002. Learn about modularization, LOD levels, and applications in noise mapping.

rtrinidad
Télécharger la présentation

Understanding CityGML: An International 3D Model Standard

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. CityGML -International standardisation of 3d city models Thomas H. Kolbe, Alexandra Stadler Technische Universität Berlin Institute for Geodesy and Geoinformation Science Chair of Methods of Geoinformation Science

  2. Motivation • Ongoing virtualisationof 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 base model entities • Initiatives • Inspire

  3. Never heard about CityGML – what‘s that? • Content • Data model and exchange format for virtual 3d city models • GML 3 application schema • Modelling of all relevant parts of the virtual city according to theirsemantics, geometry, topology and appearance • 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)

  4. CityGML‘s way to become an OGC standard CityGML 0.3.0OGC Discussion Paper 2006-03-06 CityGML 0.4.0OGC Best Practices Paper 2007-05-30 CityGML 1.0.0 (Proposal)OGC Request for Comments 2008-02-04 2008-02-192008-03-20 <<<<<<< Public Comment Phase >>>>>>> CityGML 1.0.0OGC Implementation Specification(after final OGC TC vote) coming soon  International Standard

  5. Modularisation • CityGML consists of • a core module • several extension modules  vertical subdivision

  6. Associated geometry e.g. Solid Semantic object e.g. Building … … Coherence of semantics and geometry • Use of Boundary Representation (B-Rep) for geometry modelling • Explicit relations between semantic objects and their geometrical representations * *

  7. „Availability“ of semantics • Geometric entities know WHAT they are • Semantic entities know WHERE they are and what their spatial extents are CityGML: (Up to) Complex objects with structured geometry Geometry Semantics

  8. LOD 0 – Regional model2.5d Digital Terrain Model LOD 1 – City / Site model„Block model“ without roof structures LOD 2 – City / Site modelExplicit roof structures LOD 3 – City / Site modelDetailed architectural model LOD 4 – Interior model„Walkable“ architectural models Multi-scale modelling

  9. Terrain intersection curve • Defines the intersection of an object with the terrain • Applicable to • Building • CityFurniture • GenericCityObject • Implicitly: WaterBody, Transportation, LandUse

  10. 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

  11. Appearances • Materials (similar to X3D) • Textures • Standard textures (explicit texture coordinates) • Aerial images (georeferenced) • Projected photos • Multiple appearances (themes) per object

  12. 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

  13. 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)

  14. Implementation • Growing awareness of CityGML (particularily in the US) • Discussions with • Web 3D Consortium • CTO GoogleEarth • International Alliance for Interoperability (IFC-Standard) • Selected implementations: • Feature Manipulation Engine (FME) • Snowflake Software: GO Loader, GO Publisher • Oracle 11G Spatial • Bentley Microstation, Onuma Planning System (CAAD) • CPA SupportGIS (3d GIS-System)

  15. Conversion • CityGML  FME(implemented by con terra) • IFC  CityGML (implemented by Forschungszentrum Karlsruhe) original IFC model CityGML LOD 1 CityGML LOD 2 CityGML LOD 3 CityGML LOD 4

  16. Viewer • LandXPlorer (C++) • 3D Geo, Potsdam • Hasso-Plattner-Institute(University of Potsdam) • Aristoteles 3D-Viewer (Java) • IGG, University of Bonn

  17. Target application areas

  18. 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)

  19. Application scenario 1: Noise immision mapping Noise immision simulation 3d geodata in CityGMLas input for the calculaion of noise immision maps Noise immsion mapsreported to EU(via WMS service)

  20. 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

  21. Application scenario 2: Homeland Security • CityGML building visualised using LandExplorer • from outside (left) • room-based representation of the security level (right)

  22. Application scenario 2: Homeland Security http://www.opengeospatial.org/pub/www/ows4/index.html

  23. CityGML UML example: Building module

  24. ... CityGML Schema file example: _AbstractBuildingType

  25. CityGML code example: Building in LOD 3 • <?xml version="1.0" encoding="UTF-8"?> • <CityModel xmlns="http://www.opengis.net/citygml/1.0" xmlns:bldg="http://www.opengis.net/citygml/building/1.0" • xmlns:gml="http://www.opengis.net/gml" xmlns:xlink="http://www.w3.org/1999/xlink" • xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" • xsi:schemaLocation="http://www.opengis.net/citygml/building/1.0 ../CityGML/building.xsd"> • <gml:description>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 http://www.citygml.org (example dataset for “four buildings in LOD3”)</gml:description> • <gml:name>IFC_Building_Variant</gml:name> • <gml:boundedBy> • <gml:Envelope srsName="urn:ogc:def:crs,crs:EPSG:6.12:31467,crs:EPSG:6.12:5783"> • <gml:pos srsDimension="3">5429999.751795 3449999.751795 0.0</gml:pos> • <gml:pos srsDimension="3">5430023.2 3450021.2 20.0</gml:pos> • </gml:Envelope> • </gml:boundedBy> • … • <cityObjectMember> • <bldg:Building gml:id="GEB_TH_IFC_Building_Variant_GEB_75"> • <gml:description>Building in LOD 3</gml:description> • <gml:name>Building-ADT-2006</gml:name> • <externalReference> • <informationSystem>http://www.iai.fzk.de/raw/pages/german/projekte/VR-Systeme/html/Download/ • </informationSystem> • <externalObject> • <uri>urn:ifc:oid:0deJpNQ05BvwV03c405oVp</uri> • </externalObject> • </externalReference>

  26. CityGML code example: Building in LOD 3 • <bldg:boundedBy> • <bldg:RoofSurface gml:id="GEB_TH_IFC_Building_Variant_DACH_136"> • <externalReference> • <informationSystem>http://www.iai.fzk.de/raw/pages/german/projekte/ VR-Systeme/html/Download/</informationSystem> • <externalObject> • <uri>urn:ifc:oid:3CPSkwS7f9QRfhfr5gf7dq</uri> • </externalObject> • </externalReference> • <bldg:lod3MultiSurface> • <gml:MultiSurface> • <gml:surfaceMember> • <gml:Polygon> • <gml:exterior> • <gml:LinearRing> • <gml:posList srsDimension="3">5430006.994499969 3449999.850802998 9.141580054626465 • 5430007.093499946 3449999.7517950004 8.970100114212036 5430000.906494903 • 3449999.7517950004 8.970100114212036 5430001.005499649 3449999.850802998 • 9.141580054626465 5430003.999999809 3450000.9735459564 11.086200187072754 • 5430006.994499969 3449999.850802998 9.141580054626465</gml:posList> • </gml:LinearRing> • </gml:exterior> • </gml:Polygon> • </gml:surfaceMember> • <gml:surfaceMember> • <gml:Polygon> • <gml:exterior> • <gml:LinearRing> • <gml:posList srsDimension="3">5430006.920299816 3449999.925 8.870099971160888 • 5430006.845300007 3450000.000000003 8.999999949798584 5430003.999999809 • 3450001.066800046 10.847800204620361 5430001.154700088 3450000.000000003 • 8.999999949798584 5430001.079700279 3449999.925 8.870099971160888 • 5430006.920299816 3449999.925 8.870099971160888</gml:posList> • </gml:LinearRing> • </gml:exterior> • </gml:Polygon> • </gml:surfaceMember> • …

  27. CityGML code example: Building in LOD 3 • </gml:MultiSurface> • </bldg:lod3MultiSurface> • </bldg:RoofSurface> • </bldg:boundedBy> • <bldg:boundedBy> • <bldg:WallSurface gml:id="GEB_TH_IFC_Building_Variant_WAND_78"> • <externalReference> • <informationSystem>http://www.iai.fzk.de/raw/pages/german/projekte/ VR-Systeme/html/Download/</informationSystem> • <externalObject> • <uri>urn:ifc:oid:2es$8LnAD9UxRIGzY8UaVK</uri> • </externalObject> • </externalReference> • <bldg:lod3MultiSurface> • <gml:MultiSurface> • <gml:surfaceMember> • <gml:Polygon> • <gml:exterior> • <gml:LinearRing> • <gml:posList srsDimension="3">5429999.999999809 3450004.4950001715 6.0599999968 • 5429999.999999809 3450004.4950001715 4.800000021324157 5430000.119999695 • 3450004.4950001715 4.800000021324157 5430000.180000114 3450004.4950001715 • 4.800000021324157 5430000.3 3450004.4950001715 4.800000021324157 5430000.3 • 3450004.4950001715 6.059999996886253 5430000.180000114 3450004.4950001715 • 6.059999996886253 5430000.119999695 3450004.4950001715 6.059999996886253 • 5429999.999999809 3450004.4950001715 6.059999996886253</gml:posList> • </gml:LinearRing> • </gml:exterior> • </gml:Polygon> • </gml:surfaceMember> • … • </gml:MultiSurface> • </bldg:lod3MultiSurface>

  28. CityGML code example: Building in LOD 3 • <bldg:opening> • <bldg:Window gml:id="GEB_TH_IFC_Building_Variant_OEFF_OBJ_80"> • <externalReference> • <informationSystem>http://www.iai.fzk.de/raw/pages/ german/projekte/VR-Systeme/html/Download/</informationSystem> • <externalObject> • <uri>urn:ifc:oid:3VkZRUoa97GgMdD342zHck</uri> • </externalObject> • </externalReference> • <bldg:lod3MultiSurface> • <gml:MultiSurface> • <gml:surfaceMember> • <gml:Polygon> • <gml:exterior> • <gml:LinearRing> • <gml:posList srsDimension="3">5430000.119999695 3450008.940000343 2.99999994979 5430000.180000114 3450008.940000343 2.9999999497985836 5430000.180000114 3450008.940000343 1.920000026092529 5430000.180000114 5430000.180000114 • 1.860000083312988 5430000.119999695 3450008.940000343 1.860000083312988 • 5430000.119999695 3450008.940000343 2.9999999497985836</gml:posList> • </gml:LinearRing> • </gml:exterior> • </gml:Polygon> • </gml:surfaceMember> • … • </gml:MultiSurface> • </bldg:lod3MultiSurface> • </bldg:Window> • </bldg:opening> • … • </bldg:WallSurface> • </bldg:boundedBy> • </bldg:Building> • </cityObjectMember> • </CityModel>

  29. Search the web for further examples… e.g. http://www.iai.fzk.de/www-extern/index.php?id=1412

  30. Search the web for further examples… e.g. http://www.iai.fzk.de/www-extern/index.php?id=1470

  31. 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

More Related