Painters painted the textures. There's some simple lighting on top when necessary, but it's mostly old school hand painted textures. People have gotten used to

Painters painted the textures. There's some simple lighting on top when necessary, but it's mostly old school hand painted textures. People have gotten used to viewing productions that use math (shaders) to emulate paintings and/or reality, which are incredible in their own right. But this is simply a team of extremely talented painters, who are masters of light, tasked with painting 3D models and tweaking textures per scene.