Where to find input data?

In case you would like to use City4CFD but are unfamiliar with the input data, we list below some options that can serve as a starting point.

Polygons

Building footprints are available for many locations, usually created by national mapping/cadastral agencies or voluntary geoinformation. Here you can find information on freely available data:

• Urban Analytics Lab at NUS keeps track of open government data on buildings.
• OpenStreetMap - Voluntary geoinformation, contains many buildings and other polygons/surfaces. You can follow this tutorial to extract footprints from OSM.
• Microsoft's building footprint database - Microsoft released (and maintains) a large database of building footprints all around the world. The link above also contains references to other releases by Microsoft.

Please note that there are also data that are not freely available. Data quantity and quality vary from one part of the world to another and we suggest you also do the research yourself.

Point clouds

Point clouds are less common than polygons. Some countries have released national datasets: Wiki page national datasets. For the Netherlands, a great resource for point clouds is GeoTiles.

If you have footprints with height/number of floors attribute and you just want to reconstruct the terrain, you can obtain a digital elevation model (DEM) and convert it to a point cloud with QGIS. Freely available DEM datasets include:

• Copernicus DEM - 10m/30m/90m resolution, depending on the region; most of the Earth covered
• Shuttle Radar Topography Mission (SRTM) - 30m/90m resolution, depeding on the region; most of the Earth covered
• EU-DEM - a DTM of EEA members and cooperating countries