It is really fun to work on this Civil Infrastructure project downtown Las Vegas as part of the CivilFX team. I spent a lot of time trying to go through the AutoDesk workflow of taking aerials and topography, draping them together, and getting them into 3DS Max. Turns out most of their documentation pages talk about using their Infrastructure Suite software to link the data in 3DS Max, but doing that requires a monthly subscription. So I got a trial of their software, and got frustrated at the difficulty of exporting the data to an FBX, to be able to take it anywhere I want.
So after messing around a bit with their software, I decided just to break the aerial images into squares, re-map the UV coordinates in MAX, and drape the images myself. Took a bit of triangle manipulation to make sure all the seams lined up but in the end I got a nice aerial surface in an FBX that I could import into anything. And by Anything, of course I mean Unity.