I’m making a little animation exercise, directly inspired from this video:
And here’s my current state:
As you can see, I tried to get the fire in shape, and this is where I manage to get so far. I was limited by a deadline so I couldn’t make this better, but now I need some help solving the following issues I tried to solve in this project:
The fire size
It seems quite obvious to me that in the reference, they used a sprite of a quite big fire, then scaled it down and tracked it onto the actor’s thumb in video editing.
What I want to do is basically a fire simulation but in a scale that’s more in the line with my character’s scale. I try to aim for something a little midway between the flame of a cigarette-lighter and a small wooden-stick-torch (but the size of a thumb, huh).
Right now, I have a fire that’s smaller than the default quick smoke result, but it’s not small enough, doesn’t have the kind of fire I want, and look more like a blurry mess than a fire or even a flame.
Making tests with too little resolution for the domain seemed to make the simulation unstable, the fire would “jump” from one cell to another like a small object rendered on too few pixels. So I tried with higher resolutions, as much as my deadline allowed. But still not enough IMHO.
To manage the scale of the flame, I tried to play with the domain’s Reaction Speed (panel settings > fire) and the emitter’s surface emission (panel settings > flow source). But it wasn’t enough, and making it smaller with these accentuated the resolution issue, as well as the following big issue I have.
My animation have some fast movements. Nothing fancy, yet enough for the fire to extinguish for some frames.
Playing with the resolution, reaction speed and surface emission would completely change how many frames wouldn’t be lit, but anyway I never achieved to find the right settings in order to have a small but detailed fire and that remains lit up all the time.
Fire shape & quality
I guess this is mostly solvable by more divisions in the domain settings & noise, but if there’s more to it or if you have some tips to share, I’d like to know.
I’m working on Blender 2.82 stable, using the new mantaflow system.
And here’s a lightweight version of my scene for you to play with: