Hi

I'm trying to make this fluid smoke, and so far I'm liking it a lot

I can't seem to find how to control the fading of the smoke, something like the life span on particles

There's a sample of my test, if any one has any pointers to make it more real please tell me.

thank you

I think what you're asking for is Dissipation - something that the Solver *should* support directly (it's been RFE'd). However, if you're aware of the fluid architecture, it's a one-node addition.


Basically, you scale down your density field incrementally using Gas Calculate DOP.

Thank you Jason that works

Now the issue I have is, I understand this is diffusing from start to finish in a linear fashion, at least it seems like that, could I have even more control of the fade off? , like putting that more at the end? rather than from the start?
maybe like a ramp

thanks again

Mmm, you could probably use the Volume Ramp SOP and change the apparent density after the fact?

I'll check out the volume ramp SOP.

although the gas calculate is not bad one my object is moving, looks nice, but having that extra might help for changes

okey, now, what if I want the opposite, I don't want my fluid to ever fade?, like, live for ever. could I just invert the density?, or keep it constant?

thank you again, very nice of you to help me out

Now, keep it on forever is hard because it'll eventually diffuse out into the entire volume. To keep a crisp smoke stream, hmm, you might find yourself contrasting densities using Gas Calculates.

Or, perhaps you can advect particles through your sim, regarding the particles as “smoke quanta”

I've been working on a dissipation asset that gives you the option to specify a threshold, weight and falloff curve. It can be easily done using a gas field vop. In my opinion, it might also be better to dissipate based on temperature differences. Instead of the actual smoke volume. Since you want your smoke to behave accurate but fade based on a lower temperature value that get's used to calculate the applied buoyancy force.

I'm just struggling with the fact what dissipation actually is! Something that looses energy over time? IE:

In physics, dissipation embodies the concept of a dynamical system where important mechanical modes, such as waves or oscillations, lose energy over time, typically due to the action of friction or turbulence. The lost energy is converted into heat, raising the temperature of the system. Such systems are called dissipative systems.

I like the notion of that and it's a good dop challenge