Beyond fluids local equations, that lead to costly 3D systems to solve,
physicists characterize several
structures at various scales
in fluids, and their interactions, such as
bubbles, jets, instabilities, waves, convective cells, vortices, etc.
The idea is to use directly this knowledge to generate convective phenomena,
cumulus clouds and billowing smoke are.
This allowes to separate the scales:
larges bubbles account for large range air motion,
while waves and vortices lying on a bubble surfaces are just
We indeed work on several scales:
ground air layer, heaten by the sun, producing bubbles (thermals) on hot spots.
bubble rising, up to the dew point where it becomes visible.
bubbles birth and movment inside the cloud, up to the border.
waves, degenerating into vortices, on the top of emerging bubbles,
advected along the surface.
advecting subvortices on the vortices, etc.
advected texture figuring the smaller scales.
You wonder what is the relation with texels ?
There is one.
Both a texel and a bubble (primitive to be rendered in both case)
introduce complexity in a scene by providing a
`dressing' of large simple shapes...