Exploring CityEngine in Urban Planning

This is a note following some explorations of a software tool introduced by ESRI, named City Engine specializing in modeling and 3D visualization. Compared to traditional modeling software, the tool is special due to its principle of rule-based modeling — user can create and customize a script file that controls how the 3D modeling process is generated (like an interactive design guideline), and view and play around with it offline, and possibly share across internet online. It is reportedly to be handful in modeling detail architecture, but also seems the rule-based idea is of similar nature to some of planning mentality as well.

Before jumping into details, here is an animated image showing this “rule-based” massing function:

• Generation of urban blocks

This snapshot shows an example of generation of different types of urban blocks (density, open space, orientation, etc.) with the input of parcels and street network, based on specified rule file.

CityEngine has indeed been used in large scale urban design and development project previously. A well known example is the Lakeside redevelopment project (600 acre brownfield development) in Chicago. In that project, the design team used City Engine to: 1) quickly visualize regulatory constraints, such as the zoning envelope analysis (max buildable envelope defined by land use type in zoning code); 2) Scenario testing of different design alternatives, with multiple criteria reported including energy, traffic, floor area, etc;

Figure — Rapid 3D massing model with assigned density and street network generation rule. (Bergerson et al., 2015)

This example shows the potential of value added of rule-based modeling in large scale urban design and development, as it translates the regulatory documents into spatially informed rules as a foundation for the design, and saves the time in comparing across alternative designs. Following are some early explorations using the tool’s trial version (30 day free trial. https://www.esri.com/en-us/arcgis/products/esri-cityengine/trial) Hope some can be potentially helpful.

1) Existing condition study with building massing generation

The tool offers open dataset downloadable covering the U.S., and quick generation of 3D massings with selected zone. Other existing condition data that can be download include not limited to street network, land use, zoning, etc.

ArcGIS is also integrated with the CityEngine tool, therefore, 2D data created in GIS desktop, if assigned with 3D data attribute, will be able to be integrated and viewed in the 3D based CityEngine platform, such as the zoning envelope analysis performed in the LakeSIM scheme.

2) Viewshed and view corridor analysis

To understand what can be seen from a proposed building, or vice versa, how the proposed building influences existing views. In CityEngine you can import georeferenced 3D rhino/sketchup model and create viewshed, view corridor or a 360 degree view dome around any given point.

3) Visualizing Regulations based on Land Use Type

Land use data was obtained and visualized by assigning different height limit to different land use type parcels (hypothetically the building height regulation was associated with land use types).

4) Generating building by rule file

This snapshot shows how different design of buildings (here simply just the height is the variable) can be generated with the rule file.

5) Comparing different scenarios

This snapshot shows three different scenarios and reports there development statistics.

In addition, here are several example video showing applying the tool in urban design:

https://www.youtube.com/watch?v=vMAVRnEWPEU

https://www.youtube.com/watch?v=hXw41nuONVA

Here are some example images for the Chicago lakeside development example:

1) Zoning envelope analysis

Figure — zoning envelope analysis in CityEngine showing the allowed maximum density for the potential development. (Bergerson et al., 2015)

2) 3D Generation and View

Figure — Rapid 3D massing model with assigned density and street network generation rule. (Bergerson et al., 2015)

The workflow of the LakeSIM, as exemplified in the diagram below, uses CityEngine as the central platform to implement different types of scenario modeling and analysis.

Figure — CityEngine Workflow. (Bergerson et al., 2015)

Bibliography

Bergerson, Joshua & Muehleisen, Ralph & Rodda, Bo & A. Auld, Joshua & Guzowski, Leah & Ozik, J & Collier, Nicholson. (2015). Designing Future Cities — LakeSIM Integrated Design Tool For Assessing Short- and Long-Term Impacts of Urban Scale Conceptual Designs. ISOCARP Review. 11. 48–63.