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Unity also bought SpeedTree, which did the vegetation in Avatar 1 (and in many video games). They bought Weta Digital in 2021 (https://blog.unity.com/news/welcome-weta-digital).

Blender has a FLIP plug-in I believe. The water in UE isn't great, but the "fluid flux" plug-in is surprisingly impressive for real-time water https://www.unrealengine.com/marketplace/en-US/product/fluid...

Computational Fluid Dynamics is a tricky area. The science (Fluid Dynamics) was worked out over 100 years ago, with the Navier-Stokes equations (3D partial differential equations). The engineering (the Computational part) is a whole bunch of complex and clever tricks, to overcome surprising problems like instability and dissipation, and often for some particular engineering trade-off (rather than being universally true).

Avatar 2 seems to use an underlying FLIP simulation for the water (which uses a (eularian) grid for pressure, and particles for movement), with cinematic tricks on top: foam, bubbles, and smaller (lagrangian) waves superimposed.

The Fluid Flux plug-in uses a simplified version of the Navier-Stokes equations, which represents the upward direction as an average - so it's 2D internally but looks 3D. It also just calculates once, instead of iterating. Both make it much faster. It uses this paper, which has several other tricks: https://matthias-research.github.io/pages/publications/hfFlu...



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