Introduction
We have talked about how the steps to a true Urban Digital Twin require the creation of some kind of City Information Model (CIM). Strictly speaking this doesn’t have to be a 3D model, but when we are talking about cities a third dimension can be very useful. If 3D sounds expensive it can be! Either you’re looking at expensive aerial/satellite imagery combined with photogrammetry (automated or manual) or a combination of 2D footprints digitised (automatically or manually) with LiDAR. In some countries you can find free opendata but in many places this isn’t possible so depending on your use case you need to remain flexible!
We can create 3D City Information Models from lots of types of data whether that’s extruded 2D footprints from OpenStreetMap data or perhaps even Ordnance Survey’s ‘Zoomstack’ OpenData and combine it with, for example, LiDAR which in the UK we are fortunate to have a National LiDAR Programme which allows us opendata. Obviously we need to understand how to populate our 2D polygons with height attribution from the LiDAR, if you are an Esri user your best starting point is the 3D Basemaps solution.
If you are really really lucky your city has already made a 3D CIM for you, we hope to provide a list of those cities shortly, but in the meantime we have the city of Lancaster here in the UK that we created and made OpenData for anyone to use and play with.
Lancaster City Information Model
This tutorial unlike the first one is primarily a video tutorial (hosted at GD3D’s 3DPathFinder YouTube channel), it is a quick session to get you up and running focused on using the data in ArcGIS Pro and ArcGIS CityEngine.
You can download the 3D data from Lancaster University here (please if you use publiclly ensure you cite/acknowledge us correctly) :