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Control over how smoke colors mix

I have recently be experimenting with emitting various colors of smoke to create the ink marbling effect. Is there any way to have more control over how the colors mix? I was experimenting with effectors but i didnt see anything that could control the rate of mixing, only the color intensities. I want to slow down the color mix rate a lot so the colors remain relatively separate from each other with only a little bit of mixing later on. I am hoping this will allow me to have more isolated strips of color without it all mixing into one ugly brownish color.

Just an idea for a workround but perhaps not what you're after. Until someone with technical advice can comment on what's possible, maybe do separate sims, one for each strip of color? Or at least one for each similar color range if you're doing more of a gradient.
Yeah i dont think that would get the the results im looking for unfortunately.

I want the smoke from the various colors to interact with each other so i don't see how i can separate it into 2 separate sims. Each emitter is a solid color, no gradients. I wanted the different colors to be transported through the voxel grid much further than normal before shifting. Can i control mix rate via time scale or advection stride?

I'm curious as to how the colors mix, what are the parameters that dictate this? Does the color mix by sampling the nearest voxels and normalizing the color between them? What determines the rate at which this happens, time scale? I noticed that increasing the density of the smoke does help maintain the separation in colors better but its still not a great way to control it. Also, is the color mixing additive or subtractive and what is the difference between the emitter option "add" vs "set" when it comes to color? Whenever i use "add" it makes it looks really ugly and desaturated, is this ment for non-clamped color? If so, its possible the gpu preview cant handle floating point color values.

I would love to have some sort of color mix rate param to control the speed at which colors mix. If the param is set to 0 then no mixing will occur and the voxels would remain the same color as they were when they are first created.
Understood. Apologies I'm also not familiar with how those params would affect color mixing - have just been getting into using it myself in explosions to get more variation in the smoke colors. Some ideas though that would seem to affect how they mix - until they may be able to add some control of how they mix:

--diffusion, you'd want 0 of course
--lower timescale i'd think would slow the mixing
--setting the type to: conservative may slow it
--less fine noise that would break up the sim and slower frame-change noise speed / ie larger #

Of course all these suggestions are primarily methods for slowing/minimizing smoke detail loss and voxel changes, however may also helpl with color blending speed.

Another trick to keep them to appear more separated for longer, though again probably not what your after would be to sim the first color (or color group) and then sim another while 'reading' the previous sim's values, though in this case you'd have the master initial sim that won't be affected by the 2nd however it may not be obvious depending on your needs.

The color mixing is a by-product of the advection (interpolation) and there is no control for this process.
However, we might add the diffusion control for colors that can accelerate mixing.

Kresimir Tkalcec

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