I'm an obsessive DM who runs D&D 5e sessions. I waste enormous amounts of planning time investing in one-off visuals that simply don't need to be this complex.
The idea to render this city fully in 3D came from seeing some of the amazing Substance material work out on the internet. I've seen people make shaders that single-handedly render whole cities using displacement. My own tests using that method didn't work out (See the slums to the north of the city wall) so I switched to using GPU instanced geometry. Thanks to instancing, I was able to have a model for every building, light post, cart and market stand. There are even people on the roads!
This was far too much work for the quality of the result, but I hope to apply what I learned to future city maps so I can flesh them out faster. A larger sample of building meshes would probably help, but I was on a deadline. Two of my biggest issues were controlling fog/haze and getting render passes such as Z-depth to come out. Arnold is a real pain when it comes to these things, and I couldn't find a shred of information about either subject online.
Materials (cobblestone, stone walls) done in Substance Designer. Meshes and render in 3D Studio Max (Arnold renderer). The skybox/backdrop was done in World Creator, which I found to be a pain to integrate into any sort of workflow. Final edit in Photoshop to cover up the bad grass material, add trees and give lights a bit more bloom.
If you are a DM in need of some quick city artwork, feel free to use this! Contact me if you could use a high res nearly orthographic top-down render for use as an in-universe map.