how to make multi coloured smoke

how to make multi coloured smoke

thomaslisle1309
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how to make multi coloured smoke

thomaslisle1309
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Hi I saw the post on taking a picture and applying to particles - is there a way to just paint on a mesh and use that to drive the smoke colour  - 

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thomaslisle1309
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hi. well try taking the voxel_acceleration property and putting in the scatter color  channel.  that works 

 

but I really want to take ai user data colour from a mesh and use that to drive my smoke output   anyone know how to do that ? 

 

 

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Message 3 of 4

Anonymous
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You're probably best off using particles to hold the color, then using the aero velocities (I'd run this as a particle simulation after the aero sim) to advect the particles.  

 

So first thing would be to start with a particle source that's the same as your aero source (say like a mesh with color) and have the particles use the emit location to sample your colorset.  Then once that works, feed those points to the particle solver, and use a volume_influence field with a drag to force the particles to follow the volume sim (see attached, it doesn't need to be vdb, bob will work as well).  

 

Then rasterize the color property on the particles to a volume with point_to_volume.

 

One thing I found was that I had to turn up the drag influence fairly high (like 100 or something - not totally sure why but that made it work well enough for my needs).  The other gotcha is you may need to scale velocity by your simulation speed (say if your aero timescale was slower or faster).  There are probably lots of places to fall of the wagon here depending on what is going on in your aero sim, but you'll need to experiment a bit.  I'm not 100% sure the particles track the velocity field in a 1:1 way, but I'm also not sure that it always needs to be 100 % either the further you go from the source.

 

-T

 

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Message 4 of 4

thomaslisle1309
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HI takitapsyop.  Many thanks for taking the time to respond, I will give it a whirl as soon as a get a free moment -   I have never used many of these nodes before so it may take a while to get a result - but will give it a go.   many thanks again Thomas

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