[billconan]

CUDA

vulkan,

ray tracing

fluid simulation

physics engine

[xerok]

When it comes to ray tracing and fluid simulation, I wonder if I should start with old papers and implementations, because it may be easier to get, or they are so outdated that it would be a waste of time.

[billconan]

for ray tracing you should start with https://pbrt.org/

I'm not familiar with fluid simulation.

graphics is a broad field. there are many sub fields.