I spent months trying to improve the visual fidelity of Microsoft Flight Simulator X terrain for my home town. I downloaded US geological survey heightmaps for terrain and openstreetmap vector data for all roads and building dimensions. I built custom tooling to export only the road vectors I cared about using a 2D image mask (I was also using some of the same data and tooling to attempt to build an Assetto Corsa map of my home town to drive around in in VR). I cribbed an API implementation for Google's satellite tile server from someone's code. I borrowed google maps tiles for ground textures. I learned how GIS works, played around with GDAL, played around with QGIS, wrote code to convert heightmaps into 3D models (absolutely terribly, I'm pretty sure blender includes a tool to do it ten times better) which were too big, so I wrote a tool to be able to take the same image mask from the road vectors and use it to configure a lower level of detail of the terrain away from the roads. I manually drew outlines for thousands and thousands of buildings and homes so FSX would autogenerate buildings on the terrain to match the scenery, which was mediocre because FSX only autogenerated buildings that look like old germany. I used the building footprint vector data to attempt to generate 3D models but didn't finish. I had about 100 40k X 40k pixel images of ground terrain, and it looked nice in game, but only in spring time and summer time since that's what google takes images of. So I found a 512x512 "snow" texture and wrote a python program to "resample" that texture into any green area in the ground textures and despite all my assumptions that this would be hilariously ugly, it worked extremely well. It took like 15 minutes per image though because PIL is the slowest library ever written, so I built a java program to do the actual image resampling and orchestrated it in my "pipeline" python script. I didn't want to actually have to write these massive images to disk in between steps so I found an old and unloved AMD utility to create 4gb ramdisks on Windows to use as a tempdir. I was at the point where I was manually tracing out tree polygons for the autogen scenery system and manually rebuilding the local airport from the ground up when I finally ran out of steam. I looked and found a utility that does most of the autogen scenery work for you but I never finished reading the manual. I just burnt out.

A year later or so Microsoft announced MSFS2020 and I was never happier to dump $200 on a problem. It still nags in the back of my head. It's one of the biggest projects I've ever worked on and I made so much progress.