Which mode of displacement for realistic smoke?

[TomGore]

I find displacement (render time) for the smoke very beautiful. It's slow, but it's faster than simulating the grid at similar level of detail. I've managed to get great single frames, but how to make sure that displacement will follow the smoke movement with time? In the mode I used (Surface), smoke goes on, but the displacement pattern stays like standard xyz world space procedural noise. I can't find any simple explanation in documentation. Lots about advection and GridTex, but no real-production example.

[Svetlin.Nikolov]

Hey man,

As long as you apply a static noise texture on the simulator, the displacement will remain static while the fluid moves through it. If you want the displacement to follow the shape of the fluid, then the simulation must advect texture UVWs so the displacement texture could get remapped differently over the simulator for each frame of the animation. However, this produces some nasty artifacts and was dropped from Phoenix at least for the time being.

You can give the "Advection" displacement method a shot - it implements the so-called "gridless advection" or "render-time advection" method if you plug in the simulator's own velocity using a grid tex. However, it could still be augmented using advected UVWs from the simulation, so I hope in the not-so-distant future we can bring this back.

Cheers!