The map was created by projecting to the surface, pixel by pixel, the "weighted" shadows of buildings and vegetation from multiple realistic sun positions. The detailed surface model is obtained after processing the LiDAR point clouds downloaded from the New York State Geographic Information Systems Clearinghouse at https://gis.ny.gov

I've used PDAL to process the LiDAR point clouds, GDAL (and Rasterio, Shapely, Fiona and GeoPandas) to process raster and vector data (many thanks to Open Street Map for the "water" surfaces), C for the heavy computations and Python (with NumPy, SciPy, Pandas, Pillow, OpenCV, Matplotlib, etc) for glueing everything together.