CityDrop
CityDrop helps urban planners and urban designers, with support from geospatial teams, turn survey data into 3D building models they can inspect.
Problem
Urban planners and urban designers need to understand how survey evidence becomes a building form they can evaluate. In this prototype, the evidence arrives in separate files: a classified LAS point cloud and a GeoPackage footprint. Matching them takes geospatial expertise; the sample also lacks a confirmed CRS and vertical datum, and the footprint’s meaning remains unverified.
Solution
CityDrop gives urban planners and urban designers a clear way to review this transformation with help from a geospatial team. It inspects LAS and GeoPackage inputs, makes the working assumptions explicit, generates a simple LoD1 building, and displays it in an interactive 3D viewer. The team can inspect the result, then export CityJSON and a processing report.
How
- Load the LAS and GeoPackage and inspect their classifications, layer, extent, and features.
- Select a footprint and explicitly confirm the working assumption that the coordinates use metres and the files align.
- Match class 6 building points inside the footprint with class 2 ground points near its boundary. Use nearby-ground median for the base and building-point P95 for the candidate roof height.
- Extrude the original footprint into a closed LoD1 solid and validate the CityJSON schema and geometry.
- Inspect the model in the 3D viewer, then download the CityJSON and processing report.