Gaussian splats themselves aren’t very useful for Hollywood because they don’t have any issues with higher cost representations that are more accurate.

That said, Gaussian splats are based on very old papers that do have use in Hollywood. The closest example is radiance caches for Renderman.

This would store points in space with very similar information to a splat, then interpolate between them to provide things like bounce lighting.

The first Pixar film to use this throughout was Up.