"Those are all Quake 2 textures with a bit of messing about to fit the theme - since doing this I've figured out how Quake 2 RTX materials work and modded it to load higher resolution models in maps so could improve on this a lot. There are a few free photorealistic texture packs out there that include stuff like that but would need some adjustment (roughness/specular, normal and metal/chrome maps) to make them materials in Quake 2 RTX." -Rroff
