Smoke is jittery

I am having trouble with this simulation. I always have some kind of jitter in the smoke animation (begins at 13sec.).

I thought that maybe the simulation was faulty so I redid the simulation 2x but the sims look flawless in the viewports. The animation jitters only appear in the final renderings… Maybe GI/Refraction/Volume Problem?

What render engine ? Gorgeous colours. I think perhaps it may be a geometry glass issue…show me a render without the glass.

Thanks. Rendered with Redshift.

I will try to render 10frs. without the Glass/Refraction…

If the jitter is stil there try rendering direct from bcf and the tfd container, redshift can do this…and or try with advanced render - physical…see if it is a render engine issue if the glass does not solve it.

Still jitter without the glass… I am now going to convert the bcf files to vdb and then render with Redshift Volume… Maybe that will do it…

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Is it still jittery with advanced render/physical ?

I am rendering the converted VDB in Redshift. Works at the moment like a charm. Rendered now approx. 200frames, no jitter.

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The downside is the conversion size and file size but Reactions will allow you to save to vdb on simulating.

The jitter is now gone with the VDB Method. Next problem now… :rofl:

1.Smoke stops to emit at frame 500.
2.Density has a half-life of 30 frs. (Project is set to 25fps)

Problem: There is still a lot of smoke at frame 750.
Therefore, I keyframed the Absorption Coefficient (Redshift Volume) in order to fade out the smoke (Keyframe 550 Coef 0,3 - Keyframe 725 Coef 0).
This is the render I get… I don´t know what I am doing wrong here…

Why not just make the density dissipate faster, you can even curve the rate

But if the half-life of density is at 30frs. then the whole life should be 60frs… That is what I don´t understand at the moment.

If the emitter stops at frame 500, then you shouldn´t be able to see smoke at frame 560…

It’s all maths, ratios and fluid dynamics…beyond me.
You just have to pull and push at it.

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The half life is a decay and if you have 1 unit of density it will dissipate before 10 units of density do…the more density you have the longer it takes to clear.