Technische Universitt Berlin Department of Geoinformation Science Introduction
Technische Universität Berlin Department of Geoinformation Science Introduction to City. GML Thomas H. Kolbe Alexandra Stadler Chair of Geoinformation Methodology Institute for Geodesy and Geoinformation Science Berlin University of Technology { kolbe | stadler }@igg. tu-berlin. de 19 th of May, 2009 Edu. Serv 7 Pre-Course Seminar in Ås 2009/05/19
Department of Geoinformation Science Copyright notice: This is copyrighted material. It is not allowed to distribute copies or parts of these slides and the video clips without the written consent of the author. Please note, that the presentation also contains thirdparty copyrighted material used with permission. 2 T. H. Kolbe, A. Stadler – City. GML Tutorial 2009/05/19
Overview Department of Geoinformation Science Introduction: Urban Information Modelling City. GML overview and status City. GML details Extending City. GML Application examples Summary 3 T. H. Kolbe, A. Stadler – City. GML Tutorial 2009/05/19
Department of Geoinformation Science Urban Information Modelling 4 T. H. Kolbe, A. Stadler – City. GML Tutorial 2009/05/19
Applications of Virtual 3 D City Models Department of Geoinformation Science 5 T. H. Kolbe, A. Stadler – City. GML Tutorial 2009/05/19
3 D City Modelling Department of Geoinformation Science … is far more than the 3 D visualization of reality In fact, the geometry and its appearance are only one aspect of an entity! Key issue: Semantic Modelling 6 T. H. Kolbe, A. Stadler – City. GML Tutorial 2009/05/19
Prospects of Semantic 3 D City Models (I) Department of Geoinformation Science Query your 3 D city model! (Possibly even without 3 D visualization) From which windows in which rooms of which buildings do I have visible coverage of a certain place, road, or monument? What is the best position for a new transmitter station such that the propagation of the radio signal is optimal? To what floors have all buildings in a flooded area been affected? Where audience halls in a specific area of the town (or on the campus) with more than 500 seats, 3 D projection capabilities and less than 15 min to walk from a public transport stop? Urban Data Mining, 3 D cartography 7 T. H. Kolbe, A. Stadler – City. GML Tutorial 2009/05/19
Example for 3 D Label Placement & Symbols Department of Geoinformation Science 8 T. H. Kolbe, A. Stadler – City. GML Tutorial 2009/05/19
3 D Label Placement for Augmented Reality Department of Geoinformation Science 9 T. H. Kolbe, A. Stadler – City. GML Tutorial 2009/05/19
Information Hub Department of Geoinformation Science 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 base model entities 10 T. H. Kolbe, A. Stadler – City. GML Tutorial 2009/05/19
Prospects of a Common Ontology Department of Geoinformation Science Data providers (e. g. municipalities) create 3 D models with a defined information level, which they can be sure will be required or useful for a wide range of applications this in turn makes it feasible / profitable for companies to create more advanced applications that exploit semantic information Applications can rely on a specific data quality thematic and spatial structure and (a minimal set of thematic) properties of the geo-objects 11 T. H. Kolbe, A. Stadler – City. GML Tutorial 2009/05/19
Information Modelling at Different Scales Department of Geoinformation Science Model content, structure, and employed modelling principles depend on Scale Scope (application contexts) Taken from the Homepage of the Helmholtz Research Center Karlsruhe, © Karl-Heinz-Häfele 12 T. H. Kolbe, A. Stadler – City. GML Tutorial 2009/05/19
Scope of Real Property Industry Theatre / World Country Installation / Region State / Province Natural Asset County City Underground Site Land / Parcel Facility / Built Building System Space Sub-Systems IAI-IFC Usage Water / Sea Real Property Asset City. GML Air / Space Components Level Overlay Room Structure System Space Sub-Systems Components Level Overlay Room Linear Structure Node 13 Segment © NIBS 2007
Department of Geoinformation Science Overview & Status 14 T. H. Kolbe, A. Stadler – City. GML Tutorial 2009/05/19
Requirements for 3 D City Modeling Department of Geoinformation Science Geometric 3 D and radiometric modeling Coord. Reference Systems (3 D or 2 D+1 D / geo. or proj. ) Topology Semantic modeling / Object classification Distinct thematic models / feature types with thematic attributes (DTM, Buildings, Transportation, Water bodies, Vegetation, etc. ) Common information model / standardized data model Different but well-defined granularities / abstraction levels Multi-scale modeling; support for generalisation Support 15 for the integration of different datasets T. H. Kolbe, A. Stadler – City. GML Tutorial 2009/05/19
Requirements for 3 D City Modeling Department of Geoinformation Science Geometric 3 D and radiometric modeling Coord. Reference Systems (3 D or 2 D+1 D / geo. or proj. ) Topology Semantic modeling / Object classification Distinct thematic models / feature types with thematic attributes (DTM, Buildings, Transportation, Water bodies, Vegetation, etc. ) Common information model / standardized data model Different but well-defined granularities / abstraction levels Multi-scale modeling; support for generalisation Support 16 for the integration of different datasets T. H. Kolbe, A. Stadler – City. GML Tutorial 2009/05/19
City. GML – Modelling Urban Spaces Department of Geoinformation Science Content Data model and exchange format for virtual 3 d city models GML 3 application schema Modelling of all relevant parts of the virtual city according to their semantics, geometry, topology and appearance ALKIS ATKIS [NAS] ISO 191 xx City. GML 17 T. H. Kolbe, A. Stadler – City. GML Tutorial . . . GML XML 2009/05/19
City. GML Development Department of Geoinformation Science Developed since 2002 by the Special Interest Group 3 D (North. Rhine Westphalia, Germany) Members from >70 companies, municipalities and research institutes Adopted as international OGC standard since 08/2008 Application backgrounds of the participants 18 Cadastre and Topographic Mapping Urban Planning Building Information Modelling, AEC/FM Mobile Telecommunication Environmental Simulation Training Simulation and Car Navigation Tourism and City Business Development Geoinformation and Computer Science (at its beginning) Real Estate Management T. H. Kolbe, A. Stadler – City. GML Tutorial Broad spectrum of different modeling requirements Good base for a multifunctional standard 2009/05/19
Department of Geoinformation Science Details 19 T. H. Kolbe, A. Stadler – City. GML Tutorial 2009/05/19
Modularisation Department of Geoinformation Science … City. GML consists of a core module several extension modules 20 T. H. Kolbe, A. Stadler – City. GML Tutorial vertical subdivision 2009/05/19
Coherence of semantics and geometry Department of Geoinformation Science Semantic object e. g. Building * … * Associated geometry e. g. Solid … Use of Boundary Representation (B-Rep) for geometry modelling Explicit relations between semantic objects and their geometrical representations 21 T. H. Kolbe, A. Stadler – City. GML Tutorial 2009/05/19
„Availability“ of semantics Department of Geoinformation Science City. GML: (Up to) Complex objects with structured geometry Semantics Geometric Geometry entities know WHAT they are Semantic entities know WHERE they are and what their spatial extents are 22 T. H. Kolbe, A. Stadler – City. GML Tutorial 2009/05/19
Thematic Modelling in City. GML Department of Geoinformation Science <<Feature>> <<Feature. Collection>> City. Model _Transportation Objects Relief Feature * _City. Object _City Furniture * * City. Object Group lo. D 1 Geometry lo. D 2 Geometry External. Reference - information. System: any. URI - external. Reference: External. Object. Reference. Type _Water Bodies _Site _Vegetation Geometry lo. D 3 Geometry 23 T. H. Kolbe, A. Stadler – City. GML Tutorial 2009/05/19
Multi-scale modelling: 5 levels of details Department of Geoinformation Science LOD 0 – Regional model 2. 5 d Digital Terrain Model LOD 1 – City / Site model „Block model“ without roof structures LOD 2 – City / Site model Explicit roof structures LOD 3 – City / Site model Detailed architectural model LOD 4 – Interior model „Walkable“ architectural models 24 T. H. Kolbe, A. Stadler – City. GML Tutorial 2009/05/19
Digital Terrain Models Department of Geoinformation Science DTM for each Level of Detail can be composed of TINs (Triangulated Irregular Network), Grids, 3 D Breaklines, and 3 D Mass Points Each DTM component may be restricted to be valid in a specific region by providing a validity extent polygon detailed TIN 25 T. H. Kolbe, A. Stadler – City. GML Tutorial coarse Grid Validity extent polygon can have holes which allow nested DTMs! 2009/05/19
Digital Terrain Model: UML Diagram Department of Geoinformation Science Relief. Feature City Object + lod: integer [1] * _Relief. Component extent + lod: integer [1] TIN Relief Raster Relief Breakline. Relief Mass. Point. Relief 1 1 0. . 1 gml: Triangulated. Surface gml: Polygon 26 gml: Grid. Coverage 1 1 gml: Multi. Curve gml: Multi. Point T. H. Kolbe, A. Stadler – City. GML Tutorial 2009/05/19
Example for a Nested DTM Department of Geoinformation Science Embedding of a high resolution DTM from Archeological Excavation Hole within the validity extent polygon of the low resolution surrounding DTM Image: Ph. D work of G. Agugiaro, TU Berlin 27 T. H. Kolbe, A. Stadler – City. GML Tutorial 2009/05/19
Example for a Nested DTM Department of Geoinformation Science Embedding of a high resolution DTM from Archeological Excavation Image: Ph. D work of G. Agugiaro, TU Berlin 28 T. H. Kolbe, A. Stadler – City. GML Tutorial 2009/05/19
Building Model Department of Geoinformation Science Coherent aggregation of spatial and semantical components (recursive) composition of building parts thematic surfaces (roof surface, wall surface, etc. ) [from LOD 2] building installations like dormers, stairs, balconies [from LOD 2] openings like doors and windows [from LOD 3] rooms and furniture [in LOD 4] Components contain relevant thematic attributes name, class, function, usage, construction and demolition date, roof type, address no. of storeys above / below ground, storey heights 29 T. H. Kolbe, A. Stadler – City. GML Tutorial 2009/05/19
Building Model in Lo. D 1: UML Diagram Department of Geoinformation Science _Abstract. Building 0. . 1 + function: Building. Function[0. . *] + year. Of. Construction: integer[0. . 1] + roof. Type: Roof. Type[0. . 1] + measured. Heigth: Length. Type[0. . 1] +… 1 0. . * Building. Part Building lo. D 1 Solid Geometry Implemented in City. GML using the x. NAL standard from OASIS 0. . * Address + zip. Code: int + city: String + street: String + house. Number: String 30 T. H. Kolbe, A. Stadler – City. GML Tutorial 2009/05/19
Building Model in Lo. D 2 Lo. D 1 Lo. D 2 Department of Geoinformation Science lo. D 1 Solid _Abstract. Building + function: Building. Function[0. . *] + year. Of. Construction: integer[0. . 1] + roof. Type: Roof. Type[0. . 1] + measured. Heigth: Length. Type[0. . 1] Solid lo. D 2 Solid Geometry lo. D 2 Multi. Surface lo. D 2 Multi. Curve exterior _City. Object lo. D 2 Terrain Intersection. Curve Building Installation _Boundary. Surface Roof. S. 31 Wall. S. Ground. S. T. H. Kolbe, A. Stadler – City. GML Tutorial Surface Geometry Line Geometry lo. D 2 Multi. Surface Closure. Surface 2009/05/19
Building Model in Lo. D 3+4 Lo. D 1 Lo. D 2 Lo. D 3 Lo. D 4 Department of Geoinformation Science exterior Building Installation _Abstract Building interior Building Furniture interior lo. D 4 Solid 32 lo. D 3 Multi. Surface Door Ceiling. S. Solid lo. D 4 Solid Geometry Room Opening Window lo. D 3 Solid Interior Wall. S. _Boundary. Surface Floor. S. lo. D 4 Multisurface Roof. S. Wall. S. Ground. S. T. H. Kolbe, A. Stadler – City. GML Tutorial Surface Geometry Closure Surface 2009/05/19
Building in Lo. D 4 – Interior Model Department of Geoinformation Science Can be used e. g. for escape route planning in disaster management or for mobile robotics Topology implies Accessibility Graph ! „Back room“ Passage (w/o door) „Living room“ Doorway (with door) Rooms 33 „Hallway“ Entrance door T. H. Kolbe, A. Stadler – City. GML Tutorial 2009/05/19
Spatio-semantical Composition Department of Geoinformation Science 3 D-Modell: Stadt Coburg Building. Part Building. Installation (Dormer) Building. Part Building 34 T. H. Kolbe, A. Stadler – City. GML Tutorial Building surface (Wall. Surface) 2009/05/19
Spatio-semantical Coherence (I) Department of Geoinformation Science 1 st case: structured / unstructured geometry only, possibly along with appearance properties typical models based on 3 D graphics formats like VRML, X 3 D, KML, U 3 D or legacy CAD geometry formats usable (in fact tailored) for visualizations; simple visibility computations Geometry Semantics Multi. Surface („Multi. Patch“) Surface 35 Surface T. H. Kolbe, A. Stadler – City. GML Tutorial 2009/05/19
Spatio-semantical Coherence (II) Department of Geoinformation Science 2 nd case: simple object with unstructured geometry identifiable objects with a set of simple thematic properties (this is the modeling capability level of e. g. Shapefiles) typical result of (current) photogrammetrical registration systems usable für visualizations & simple thematic queries; simple visibility computations Geometry Semantics Multi. Surface („Multi. Patch“) Building Surface 36 Surface T. H. Kolbe, A. Stadler – City. GML Tutorial 2009/05/19
Spatio-semantical Coherence (III) Department of Geoinformation Science 3 rd case: simple object with structured geometry typical result of 3 D modelling tools, but also from (a few) photogrammetrical registration systems Geometry Semantics Composite. Solid Building Solid Surface 37 Surface T. H. Kolbe, A. Stadler – City. GML Tutorial 2009/05/19
Spatio-semantical Coherence (IV) Department of Geoinformation Science Geometry Semantics Multi. Surface („Multi. Patch“) Building Surface case: complex object with unstructured geometry House Garage 4 th Data is typically derived from Building Information Models like IFC or retrieved from Facility Management 38 T. H. Kolbe, A. Stadler – City. GML Tutorial Stairs Roof. Surface Wall. Surface 2009/05/19
Spatio-semantical Coherence (V) Department of Geoinformation Science 5 th case: spatio-semantical coherently structured object Highest quality level; can be obtained e. g. by careful derivation from Building Information Models like IFC Geometry Semantics Composite. Solid Building Solid Surface 39 Surface T. H. Kolbe, A. Stadler – City. GML Tutorial House Garage Roof. Surface 2009/05/19
External references Department of Geoinformation Science 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 40 T. H. Kolbe, A. Stadler – City. GML Tutorial 2009/05/19
Appearances Department of Geoinformation Science Materials (similar to X 3 D) Textures Standard textures (explicit texture coordinates) Aerial images (georeferenced) Projected photos Multiple 41 appearances (themes) per object T. H. Kolbe, A. Stadler – City. GML Tutorial 2009/05/19
Georeferenced Textures Department of Geoinformation Science 42 T. H. Kolbe, A. Stadler – City. GML Tutorial 2009/05/19
Further City. GML Concepts Department of Geoinformation Science Support for Topology Shared geometric primitives can be referenced using XLinks Support for generalization of 3 D data Generalized objects are linked to the original objects on the larger scale Support for spatial homogenization / integration e. g. Terrain Intersection Curves (for integration of 3 D objects with the terrain) 43 T. H. Kolbe, A. Stadler – City. GML Tutorial 2009/05/19
Department of Geoinformation Science Extending City. GML 44 T. H. Kolbe, A. Stadler – City. GML Tutorial 2009/05/19
Application Specific Extensions to City. GML Department of Geoinformation Science City. GML is considered a base or core information model for virtual 3 D city models But: Specific applications need specific extra information typically in close interaction with City. GML base information Examples Environmental simulations like noise immission mapping need information about noise absorption of surfaces Cultural heritage needs to augment objects by their heritage and history, and has to consider the development along time Utility networks need to represent pipes, pipe tunnels, connectors, transforming devices 45 T. H. Kolbe, A. Stadler – City. GML Tutorial 2009/05/19
Extending City. GML Department of Geoinformation Science 1. Generic Attributes & Generic. City. Objects every City. Object can have an arbitrary number of extra attributes allows to augment objects like Buildings, Roads, etc. without the need of new application schemas Generic. City. Objects can have arbitrary geometries (and generic attributes) for every LOD “extension during runtime“ 2. Application Domain Extensions (ADE) 46 extra XML schemas referring to the City. GML XML schema (defined by information communities) extensions to be formally specified in XML schema T. H. Kolbe, A. Stadler – City. GML Tutorial 2009/05/19
Generic Objects and Attributes Department of Geoinformation Science Simple to use extension mechanism Generic. City. Object is used as proxy to model and exchange features which are not provided by City. GML Generic Attributes can be used to establish (informal) application specific property sets for feature types Some disadvantages No further semantic structuring of generic objects and attributes Possible naming conflicts Limited number of predefined attribute types: integer, double, string, date, URI 47 T. H. Kolbe, A. Stadler – City. GML Tutorial 2009/05/19
Example for Generic Attributes Department of Geoinformation Science <Building gml: id=“Building 0815"> <!-- generic attributes --> <string. Attribute name=“Building. Owner"> <value>Mr. Smith</value> </string. Attribute> <double. Attribute name=“Value"> <value>3500000. 0</value> </double. Attribute> <!-- specified properties of feature type “Building” -> <lod 2 Solid>. . . </lod 2 Solid> </Building> 48 T. H. Kolbe, A. Stadler – City. GML Tutorial 2009/05/19
Application Domain Extensions (ADE) Department of Geoinformation Science Information Communities should be able to define extensions on their own they must be able to associate new attributes to concrete City. GML feature types formal definition of new properties / feature types in XML schema similar situation to the specification of GML application schemas Different extensions should be usable simultaneously e. g. City. GML Building features augmented both by properties from real estate and noise pollution simulation Requires combinable application schemas 49 T. H. Kolbe, A. Stadler – City. GML Tutorial 2009/05/19
Example of application specific attributes Department of Geoinformation Science Example for a City. GML Building feature with application specific extra information (qualified by extra namespaces): <Building> <function>1000</function> <lod 2 Solid>. . . </lod 2 Solid> . . . <noise: immission. Points> <gml: Multi. Point>. . . </gml: Multi. Point> </noise: immission. Points> <noise: building. Habitants>8</noise: building. Habitants> <real. Estate: value currency=“EUR“>400000</real. Estate: value> </Building> 50 T. H. Kolbe, A. Stadler – City. GML Tutorial 2009/05/19
Application Domain Extensions (ADE) Department of Geoinformation Science Well-defined mechanism to extend City. GML with application specific information Additional spatial and non-spatial properties, relations, associations, new feature types Semantic and geometric structuring follows the data needs ADE hooks allow for augmenting the predefined City. GML features No formal standardization process needed Specification within their own XML Schema Allows for XML validation of ADE enriched documents Ensures semantic and syntactic interoperability Globally unique XML namespace prevents naming conflicts ADEs can be used simultaneously within one instance documents 51 T. H. Kolbe, A. Stadler – City. GML Tutorial 2009/05/19
Application Domain Extensions (ADE) Department of Geoinformation Science Noise. Simul. Disaster management . . . ALKIS ATKIS [NAS] ISO 191 xx City. GML 52 T. H. Kolbe, A. Stadler – City. GML Tutorial City. GML ADEs . . . GML XML 2009/05/19
ADE implementations Department of Geoinformation Science Available City. GML ADEs (excerpt) ADE Noise. ADE Application domain Noise pollution simulation Proposed by SIG 3 D Subsurface. ADE Underground features, e. g. tunnels SIG 3 D CAFM-ADE Computer Aided Facility Management Hydro. ADE 3 D flood simulation Bridge. ADE Comprehensive model (under development) for bridges Utility. Network. AD Utility networks, e. g. City. GML electricity Tutorial E 53 T. H. Kolbe, A. Stadler –water, TU München HFT Stuttgart SIG 3 D 2009/05/19
Department of Geoinformation Science Application Examples 54 T. H. Kolbe, A. Stadler – City. GML Tutorial 2009/05/19
The Official 3 D City Model of Berlin Department of Geoinformation Science www. 3 d-stadtmodell-berlin. de 3 D visualization is the result of a portraying of Berlin‘s 3 D city model (modeled according to City. GML) 55 T. H. Kolbe, A. Stadler – City. GML Tutorial 2009/05/19
Noise immision mapping Department of Geoinformation Science EU Directive: Minimisation of noise immissions Calculation Westphalia of noise immission maps for whole North Rhine- Data provision and exchange via City. GML using web services (WFS, WCS, WMS): 8. 4 million 3 d buildings in LOD 1 3 d street network in LOD 0, with additional noise related attributes 3 d rail network in LOD 0 3 d noise barriers in LOD 1 Digital terrain model (10 meter resolution) 56 T. H. Kolbe, A. Stadler – City. GML Tutorial 2009/05/19
Noise immision mapping Department of Geoinformation Science Noise immision simulation 3 d geodata in City. GML as input for the calculation of noise immision maps 57 T. H. Kolbe, A. Stadler – City. GML Tutorial Noise immsion maps reported to EU (via WMS service) 2009/05/19
Homeland security Department of Geoinformation Science 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: City. GML and IFC 58 T. H. Kolbe, A. Stadler – City. GML Tutorial 2009/05/19
Homeland Security Department of Geoinformation Science City. GML building visualised using Land. Explorer from outside (left) room-based representation of the security level (right) 59 T. H. Kolbe, A. Stadler – City. GML Tutorial 2009/05/19
Homeland Security Department of Geoinformation Science http: //www. opengeospatial. org/pub/www/ows 4/index. html 60 T. H. Kolbe, A. Stadler – City. GML Tutorial 2009/05/19
Department of Geoinformation Science Coming to the end… 61 T. H. Kolbe, A. Stadler – City. GML Tutorial 2009/05/19
Summary Department of Geoinformation Science City. GML is a Geospatial Information Model (based on ISO 191 xx) and Exchange Format for virtual 3 D city and regional models (implemented as GML 3 Application Schema) City. GML represents Geometry, Topology, Semantics, and Appearance esp. semantic / structural information is needed for a range of applications gives city model data enough space to „grow“ with respect to geometric, radiometric, and semantic contents & complexity to semantic qualification / interpretation to geometric / topological correctness 62 T. H. Kolbe, A. Stadler – City. GML Tutorial 2009/05/19
What is City. GML‘s Use for Research? Department of Geoinformation Science Base model / base ontology for geodatabase developments project specific extensions (like relations or new feature types) Could be target model of 3 D extraction methods concerning feature types, aggregation structures 5 discrete scales usable for 3 D generalisation Exchange format lossless information exchange between subsystems / Geo. DB increasing number of available implementations / 3 D-Geo. DB Good amounts of real testdata available Berlin, Bonn, Bochum, Hamburg, Stuttgart, Recklinghausen, … also 3 freely accessible Web Feature Services delivering City. GML 63 T. H. Kolbe, A. Stadler – City. GML Tutorial 2009/05/19
Technische Universität Berlin Department of Geoinformation Science Introduction to City. GML Thomas H. Kolbe Alexandra Stadler Chair of Geoinformation Methodology Institute for Geodesy and Geoinformation Science Berlin University of Technology { kolbe | stadler }@igg. tu-berlin. de 19 th of May, 2009 Edu. Serv 7 Pre-Course Seminar in Ås 2009/05/19
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