[amarant]

This is great! When I have some leftover time I want to try copying this implementation for 3D. I reckon I could get away with minimal modifications to support the third axis...I think...

That'll perform even worse though, hopefully my CPU can handle it or I'm gonna need a lot of leftover time to make a shader

[myzek]

Yes, this should be relatively easy to extend to 3D. Performance might pose some issues so I advise to stick to a small grid, or look for optimizations like decreasing the amount of Gauss-Seidel loops etc. Moving this into a C++ library would also probably help a lot

[markstock]

You are correct: Stable Fluids extends to 3d relatively easily.