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  • Writer's pictureTreisTek

Smart City and CityGML Modeling

Updated: Jul 15, 2021

Smart City models are no longer just the ‘nice to have’ side projects that the governments keep attracting attention in the rich and exotic cities. They have become a necessity.

Smart City Modeling

What is GML?

The Geography Markup Language is the XML grammar defined by the Open Geo-spatial Consortium to express geographical features. GML serves as a modeling language for geographic systems as well as an open interchange format for geographic transactions on the Internet.

What are Smart city models?

Smart city models are digital models of urban areas that represent terrain surfaces, sites, buildings, vegetation, infrastructure and landscape elements in three-dimensional scale as well as related objects belonging to urban areas.

Smart City and CityGML

  • CityGML geometries parsing to build a data structure containing a hierarchical structure of buildings, sub-objects (roofs, walls) and geometry.

  • Renderable geometry generation from CityGML on server side.

City is decomposed into meaningful objects with clear semantics and defined spatial and thematic properties -

  • Buildings, roads, railways, terrain, water bodies, vegetation, bridges.

  • Buildings may further decompose into different storeys (and even more detailed into apartments and single rooms).

  • Application specific data are associated with the different objects.

Why Smart City/ CityGML models?

There is an ever-increasing demand for the collection, integration, management and sharing of reliable spatial information. Municipalities are expected to meet ever-increasing demands on infrastructure due to the following reasons:

  • Population growth

  • Aging infrastructure

  • Aging workforce

  • Reduced tax revenues

  • Increased global warming

  • Industrialization

So, planning of every detail in a city becomes of utmost importance.

Smart City/ CityGML Models – Project Specifications:

  • Level of geometric detail, LOD1, LOD2, LOD3 and LOD4 types (OGC): individual roofs (domes, gables, mansards), dormers, elevator shafts, ventilation, etc.

  • Photorealistic textures from vertical and oblique aerial images.

  • Delivered 3D formats: 3DS, GML, OSGB, OBJ, City GML, etc.

  • Structuring of CityGML models: one "ID" par building or group of buildings with associated placement files.

  • A detailed and accurate CityGML Modeling with texture and layers.

  • Containing all the visible details (Walls, Beams, Balconies, Stairs, Windows, all architectural motifs. Etc. will be extracted from reference images and used to texturing it will be done in 3DS Max.)

CityGML Modeling

TreisTek and Smart City/ CityGML models

TreisTek is an early mover in adopting and comprehending the technologies required to address this emerging trend of using Smart City/ CityGML Models which help in analyzing the urban issues and implementing new urban infrastructure designs.

We have already completed more than 10,000 buildings CityGML models in the LOD2 and LOD3 with measured wall and roof colors for over 20 cities globally. Our CityGML models are used for traditional applications such as –

  • Urban planning

  • Environmental modeling

  • Navigation and

  • Location-based services.

At TreisTek, CityGML models are typically constructed at various level of details (LOD) to provide notions of multiple resolutions and at different levels of abstraction. Other metrics such as the level of spatio-semantic coherence and resolution of the texture can be considered a part of the LOD.

The customer is beginning on this ambitious and technologically challenging project as the foundation for developing an intelligent CityGML model of the country to support its growth as envisioned in its Master Plan and provide the data necessary to enable the infrastructure, environmental, security and other agencies of the Government to better fulfill their missions.

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