I am working on a flame simulation that is driven by a particle emitter (Emitter > Flow Source) and everything has been going fine. The only problem is that the simulation is going EXTREMELY fast.

Here's what's happening:

Hypersonic Fire

I've read the way to slow down particles is by selecting your emitter and changing the integration timestep:


This seems to work ONLY on the particles, not the simulation itself. See this image:

Simulation Demo

I've also tried lowering the Domain's Time Scale and it does nothing, even at extremely low or high values:

enter image description here

So, in conclusion, how do I slow this thing down? Any advice at all would be hugely appreciated.

Here is a blend:

(Just bake and then play. Bonus fire shader in the domain's material slot, set to cycles to see)


1 Answer 1


To slow down your simulation you can decrease the timescale. Of course, you have to free your baked data and bake it again. It works.

enter image description here


enter image description here

  • $\begingroup$ As I mentioned in my original post, I've already tried this, and it doesn't work. The reason why your gif looks like the simulation is slow is because the FPS isn't at 24 on playback due to stress on your CPU or some other bottleneck. You'll notice that as soon as the fire hits the right side of the domain and the FPS picks up, everything is extremely fast again. $\endgroup$
    – fmotion1
    Aug 15, 2021 at 19:23
  • $\begingroup$ No it’s not, that’s why I showed you the timeline. The fire was much quicker before on the right side. I am pretty sure you didn’t bake it and didn’t compare it right. Else you would see the difference. $\endgroup$
    – Chris
    Aug 15, 2021 at 20:05
  • $\begingroup$ And the timeline progress has NOTHING to do with slow CPU 🤦🏻‍♂️🤦🏻‍♂️ $\endgroup$
    – Chris
    Aug 15, 2021 at 20:07
  • $\begingroup$ Just look at your gif - the fire reaches the right side at maybe 7-8 frame. Mine reaches at around 15 the right side. And I just changed the timescale - which - you think - doesn’t work. But if you could compare - you would see it. But obviously you cannot compare by facts. $\endgroup$
    – Chris
    Aug 15, 2021 at 20:15
  • $\begingroup$ I just compared, and yes, you are correct. Really sorry about that, I came off pretty condescending. Now the flame is a lot more flat though. It doesn't spread apart at the end of the flame. I need to find a way to accomplish that. Higher velocities will do it, but then the simulation goes crazy fast again. $\endgroup$
    – fmotion1
    Aug 15, 2021 at 21:12

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