[hnuser123456]

I do have a parameter so that each particle only takes into consideration other particles within 750 units, when the free space is 3000x3000x3000 units, but this parameter did not seem too critical, and it's still calculating the distance between each pair twice technically, so I guess I could speed that up. Vector/"table?" operations seemed slower than plain loops, not sure if there's plain interpreter speedup possible there?

[lukko]

These references helped me a lot when building a spatial hashed fluid sim that runs on the GPU:

https://developer.download.nvidia.com/presentations/2008/GDC... https://wickedengine.net/2018/05/21/scalabe-gpu-fluid-simula...

(See from page 16 on the NVIDIA presentation)