I was responsible for creating the atmospheres and working with our tech art team to find the best solution for our base lighting on the city. For the night atmosphere, I created the base light fixture prefab lighting kit that would be propagated throughout the city. Districts were then split among the lighters who would make sure they didn't have dark areas and would spot light areas as needed. We have an incredible environment team that built an amazing city and made lighting it all that much easier. Our core and tech teams are the best I've ever worked with.
For more information on how this came together, please check out a talk that myself, Ryan Benno, and Matt McAuliffe gave at GDC this year. - https://www.youtube.com/watch?v=RgUaPmDJ2r4
Skies and concept art by Nicholas Schumaker
https://www.artstation.com/nicholasschumaker
Tech Art: Chris Perrella
https://www.artstation.com/chrisperrella
Shader artist: Matt McAuliffe
https://www.artstation.com/wolfyyy