Diffusion

[gardeler]

In fume there is a "diffusion" value, that makes the smoke more soft over time. (like cigarette smoke does.) Is there a similar option in Phoenix?

[georgi.zhekov]

The Smoke dissipation does this.

[gardeler]

Awesome! So it is not the same as in fume where the smoke "dissolves"? I guess I have confused the two.

[georgi.zhekov]

I have misunderstood you I guess - smoke dissipation will make the smoke dissolve. If you would like to make the smoke appear softer you need to use Classic Advection or Forward Transfer.

[gardeler]

Ah, ok. Yeah, I'm already using classic, so I was hoping there were something else I could try.

[Svetlin.Nikolov]

Ah, you could use the Smoothing in the Input panel. It's a render-time/preview option and does not require simulating again. It will blur your smoke channel and you could animate it to increase over time.

[gardeler]

Thanks for the reply Svetlin. I really have to try this, but it was not yet released for volumeGrid for maya, right?

But I was reading through the release notes on in the nightly builds. There I found a new feature that you can down-sample your grids now. Could I resample my detailed smoke down to a more blurred version?

Thanks

Martin

[Svetlin.Nikolov]

Ah, yes, this is right. I think we already had this conversation, sorry about that.

You can resimulate to a lower resolution with Phoenix, indeed.

[gardeler]

Ok, I'm testing the smoothing now, and I can see a small change using default values. It seems to do the right thing, I just need much more of it. How do I crank it up? I have tried to change the settings, but no "major" change...

[Svetlin.Nikolov]

The strongest effect you can get is by setting all 3 options to zero. If this is not enough, then I'm afraid these are all the tools that we have currently.

How strong a diffusion are you trying to achieve? Would it be possible to share a screenshot of how it looks now?

[gardeler]

Thank you for trying to help out! I guess what I am trying to achieve is to get the smoke to spread out in the volume more even way over time. So in the beginning of the emission it is dense and sharp, but over time, the smoke will spread out and loose texture.
If you look at this picture and look what happens on the left side. I have something that looks like the right side. In fume you could use the diffusion to achieve this effect.

http://www.waterdamagedhomes.com/wp-...Fire_Smoke.jpg

Here is also an example of smoke that is sharp in the emission and softens over time.
https://www.youtube.com/watch?v=V42sX_wz0qg


Any ideas are very welcome!

[Svetlin.Nikolov]

Would it be possible to share how your results look so far? I think that if you add a turbulence helper with a small scale and low strength, and combine this with a little bit of smoke dissipation to thin out the smoke with time, you would get the effect you are looking for.