EN/CityGML-Tutorial/chapter-7:-ArcGIS-CityEngine.md

 # What is ArcGIS CityEngine
 ArcGIS CityEngine is a specialized 3D city modeling tool used frequently to quickly generate massive geo-referenced 3D city models. CityEngine is a part of the ESRI software suite, specialising in geospatial software. CityEngine is developed around ESRI's [3D City Information Model (3DCIM)](https://iopscience.iop.org/article/10.1088/1755-1315/18/1/012172/pdf), which defines a protocol to model, update, and visualise 3D city models on the web, as shown in the figure below. Additionally, themes such as built environment, legal environment, natural environment, and base maps allow users to organize, manage, and model different objects of the physical (real) world as urban digital twin datasets in greater detail. 
 
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 ![3dcim](uploads/655f45cf0a460fe7b7f51c6b20d554d5/3dcim.png)
 
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 ESRI's 3DCIM thematic structure was developed to allow data exchange to and from other data models such as CityGML. CityEngine is a [procedural modeling](https://people.eecs.berkeley.edu/~sequin/PAPERS/Parish_Mueller_Cities.pdf) software that relies on its built-in computer-generated architecture (CGA) shape grammar programming language to model different thematic structures of 3DCIM. Whereas generic 3D modeling tools such as SketchUp, Autodesk AutoCAD 3D, and Rhinoceros3D require manual modeling of 3D models and are used in various industries, CityEngine combines procedural - parametric modeling with CGA programming language to generate 3D urban environments, thus getting classified as a specialist 3D urban modelling software. Due to procedural modeling, the construction of the 3D city modeling process becomes faster, with greater control over randomness. For example, an increasing number of building floors, changing roof geometries, or even increasing the level of details can all be done by making the changes in the CGA rule file rather than manually re-modeling the entire building as in the case of generic 3D modeling tools. 
 
 A high level workflow for generating 3D city models in CityEngine is shown in the figure below:
 
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 ![ce_workflow](uploads/33a8fa445e5d891d518076d89fdd4c08/ce_workflow.png) 
 
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 1. Data Import (shapes + attributes): 2D vector data can be imported to CityEngine in different formats, such as shapefile, geodatabase, or CAD. In case, 2D vector data is not available. CityEngine's built-in connection to open street map (OSM) can be used, or using CityEngine's inbuilt shape creation tool, road networks and subsequently building parcels can be generated parametrically. Basemaps such as satellite imagery and terrain/heightmap map can be downloaded using CityEngine inbuilt connections to ESRI web map services. 
 
 2. Creating/Applying CGA Rule File: Using CityEngine's built-in CGA rule file library, 3D city model elements such as buildings, street network, vegetation, landcover, and street furniture can be modeled in 3D. If the built-in CGA rule file library does not satisfy the purpose, users can either edit the existing CGA code or develop a custom CGA rule file. 
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 [CityEngine Tutorials](https://doc.arcgis.com/en/cityengine/latest/tutorials/introduction-to-the-cityengine-tutorials.htm)
 
-[Free Trial version of CityEngine](https://www.esri.com/en-us/arcgis/products/arcgis-cityengine/trial)  - Requires [ESRI Account](https://www.esri.com/en-us/arcgis/products/arcgis-online/trial) / Contact for Matthias Reuss (2/181) for CityEngine education licence
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+[Free Trial version of CityEngine](https://www.esri.com/en-us/arcgis/products/arcgis-cityengine/trial)  - Requires [ESRI Account](https://www.esri.com/en-us/arcgis/products/arcgis-online/trial) / For HFT Stuttgart students Contact for Matthias Reuss (2/181) for CityEngine education licence.
 
-[Lecture presentation (in English)](https://moodle.hft-stuttgart.de/mod/folder/view.php?id=213301) - For Masters in Photogrammetry and GeoInformatic students in CIV subject (Requires access to Moodle/CIV-Visualisation)
+[Lecture presentation (in English)](https://moodle.hft-stuttgart.de/mod/folder/view.php?id=213301) - For HFT Stuttgart Masters in Photogrammetry and GeoInformatic students in CIV subject (Requires access to Moodle/CIV-Visualisation)
 
 [Lecture exercise (in English)](https://transfer.hft-stuttgart.de/gitlab/coors/3d-stadtmodelle/-/tree/master/CityGMLTutorial/CityEngine_Tutorial)