Unreal engine, dx12 by default but dx11 can be activated with a command line switch or maybe in the steam launcher (I have the GOG version). RDR2 profile works for dx12, I tried Conan Exiles with dx11 and got G3D, but there was a lot of shader flickering. Probably a different profile would work better, but I haven’t had a chance to look any further.
Distant objects look flat of course but up close your ship, the other ships, asteroids, space debris, etc. look pretty good. Given the type of game, I’m not sure that G3D is going to buy you much except for a resizable HUD and a 50% performance penalty.