fumefx 2.0 post processing flickering?


I have some.fumefx post processing flickering going on in my renders. I scaled down the retming from 1.0 to .3 in my fumefx post processing. the motion looks good, however i am getting weird flickring in my renders. I think this is due to the post processing calculation. Anyone know a fix?

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thanks in advance


I ran into this problem during “Alice in Wonderland” back in December. It appears that there’s a limit to how much you can slow down the fluid with post-processing before it starts to artifact. In testing I found that I couldn’t push it below 0.25 however it sounds like you’re above this. The moat mist was done in a 3 stage process of running a coarse grid simulation, then a wavelet sim on a fine grid and finally retimed to 25% of the original speed. Perhaps running wavelet turbulence smoothed out the density values during the retime?


hey dude,
thanks for the suggestion. Before retime in fumefx. what was the most common way to slow down the movement of a large scale smoke/cloud? Curious as i have seen some demos done by another brandon. :smiley: any feedback will be appreciated


Before Fume 2.0 it was mostly a matter of playing with Velocity Dampening and Time Scale. In general, it’s good to be working with accurate scene scale when doing simulations in the first place.


I don’t suppose anyone has a workaround-or confirmation of a cause for this?
So far i can’t avoid the flickers with retimes. Two different and unrelated test scenes both seem to do it. One was fire and smoke-the other smoke only (large scale style).
I am using FumeFX 2.1a.
Tried going through wavelet-but it didn’t help. I am only retiming by .5…
Seems like a bug really.


You should contact FumeFx support then.


Yes -ya just know they seem to be offline since Friday. Neither myself nor a colleague can login. Is it us(fire wall)-can anyone confirm they can login to the afterworks web today?


One thing that can save you in a pinch is to take your camera and geometry and speed everything up x number of times.

Render out the frames then use o-flow or twixtor or whatever to re-time the smoke to the original frame count.

Often smoke works surprisingly well because a little bit of error in the warping is not usually noticeable.

This is really only a trick you would want to bust out if you have a deadline and no other options.


ahh twixtor. i love that plugin. it can be forgiving if the smoke is engulfing the view. But if there are alot of high details stuff. twixtor can generate unwanted artifacts. I tried retiming again with fumefx, played around with the lighting and shading and was about to get rid of the flickering. i think the density of the smoke can contribute to the flickering. which could be a result of the mapping for the smoke looping over a period of time. If one lowers the density i think it becomes less visible.


Its very inconsistant. I’ve got one shot-just smoke where the entire thing flickers.
I’ve got another where just a core of the fire seems to do it-if I hide that fire from rendering
that one’s smoke is flicker free.

I’m of the opinion currently that i will test PP early in my setups -when everything is ‘about’ right just tweaking needed. If if shows up i just won’t try it again for that shot. nada.

I’ve gotten pretty used to using time scale for slowmotion…


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