Smoke visibility

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wasd
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Smoke visibility

Post by wasd » Tue May 14, 2019 7:23 am

I have a questions about smoke:
1) Is it possible to make smoke from a certain smoke flow invisible, i.e. not rendering it at all?
2) Is it possible to get smoke data per smoke flow, not entire domain?
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Dade
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Re: Smoke visibility

Post by Dade » Tue May 14, 2019 10:20 am

wasd wrote:
Tue May 14, 2019 7:23 am
I have a questions about smoke:
1) Is it possible to make smoke from a certain smoke flow invisible, i.e. not rendering it at all?
What is exactly the mean of "smoke flow" ?

You can make it totally transparent: 0.0 scattering and absorption.
wasd wrote:
Tue May 14, 2019 7:23 am
2) Is it possible to get smoke data per smoke flow, not entire domain?
See the question above.
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B.Y.O.B.
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Re: Smoke visibility

Post by B.Y.O.B. » Tue May 14, 2019 10:53 am

This would require some kind of ID grid (which does not exist). Or it would be necessary to save the smoke of different flows to different grids, but I think this is not possible in Blender - everything is baked into the same grid.

What you could try is using a distinct color channel for each flow (R, G or B) and mask them by using the new "split RGB" texture in the latest daily builds.

@Dade: A smoke flow in Blender is an object that emits/generates smoke.
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wasd
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Re: Smoke visibility

Post by wasd » Tue May 14, 2019 11:02 am

Dade wrote:
Tue May 14, 2019 10:20 am
wasd wrote:
Tue May 14, 2019 7:23 am
I have a questions about smoke:
1) Is it possible to make smoke from a certain smoke flow invisible, i.e. not rendering it at all?
What is exactly the mean of "smoke flow" ?

You can make it totally transparent: 0.0 scattering and absorption.
Yep, I did something like that, though it's 1.0 for no absorption. It's not very convinient, hence the question.
CPU Bidir (sometimes GPU Path) + Metropolis | Log Power | Core i5-4570

wasd
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Re: Smoke visibility

Post by wasd » Tue May 14, 2019 11:12 am

B.Y.O.B. wrote:
Tue May 14, 2019 10:53 am
This would require some kind of ID grid (which does not exist). Or it would be necessary to save the smoke of different flows to different grids, but I think this is not possible in Blender - everything is baked into the same grid.

What you could try is using a distinct color channel for each flow (R, G or B) and mask them by using the new "split RGB" texture in the latest daily builds.
It's not very nice of blender, then.
I'd try this split rgb. For now I colored "invisible" smoke black, and visible – white.
Also, there's "Use modifier during render" switch, but it seems it does nothing with smoke flow.
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B.Y.O.B.
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Re: Smoke visibility

Post by B.Y.O.B. » Tue May 14, 2019 11:15 am

With a setup like this, you can create masks for up to three smoke flow objects:
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2019-05-14_13-14-04.png
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