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Quite impressed by all of Gleb Alexandrov's scenes with some amazing dust floating around.

(To see what I'm talking about > http://www.creativeshrimp.com/lighting-tutorial-atmospheric-effects-dust-book-10.html)

And I started working last night on a scene that is going to need the same sort of atmospheric dust in the air. But when I looked around on how to create dust particles in the air there was nothing there. Not even anything I could adapt from a tutorial. Everything was from 2009 before volumetrics was even introduced.

Someone in an older tutorial did use a particle system and used a scaled down icosphere as a mesh for each particle, but experimenting with that made everything look really tacky.

Is there a way to do dust particles that I'm not thinking of?

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  • $\begingroup$ Put plain and simply, yes. And it is not easy. The best way to do this is to fiddle around yourself, however I can think of a few great ways to do this. Mesh Particles suspended in the air, Depth of Field to blur the particles except at the focal point, Volumetric rays to highlight light sources, and post-processing. Never underestimate the power of good post-processing work. IMPORTANT: Make sure your particles are random (size, loc), translucent, and are small enough. I may be able to make an in-depth answer at some point. $\endgroup$ – VRM May 3 '15 at 1:30
  • $\begingroup$ related: blender.stackexchange.com/a/5051/1853 $\endgroup$ – cegaton May 3 '15 at 16:14
  • $\begingroup$ I don't have an issue creating the particles, its rendering them correctly. $\endgroup$ – meed96 May 3 '15 at 16:21
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    $\begingroup$ @Jerryno If you look at Gleb's article (link in original piece) you will see just above step 3 a before and after for dust particles. Dust particles ≠ Volumetrics $\endgroup$ – meed96 May 4 '15 at 21:31
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    $\begingroup$ @meed96 Dust particles = Volumetrics. Just tiny microscopic ones that cannot be seen as individual dots. For the bigger dust where you can see individual particles use the particle system with icospheres. Its best to mix both. You can also ask Gleb for his setup if he wishes to share. $\endgroup$ – Jaroslav Jerryno Novotny May 5 '15 at 7:24
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Mix an volumetric environment with a particle system:

  • density of volume scattering will determine the amount of microscopic dust particles that create light rays

  • particle system will add visible dust

Points to keep in mind:

  • create the light super-bright and scatter density tiny - that way the small particles get enough light.

  • give the particles translucent shader or a bit mixed-in emission if they are too dark

  • the particles need to appear small on camera so they blend with the light-shafts (smaller the better). Particles should be also random in size.

A closeup of such out-of-focus dust:

enter image description here

the black border is there to fight the white page background

Settings (depends on scene size, light distance and camera):

  • scatter density: 0.003
  • used light: Point, strength: 5000
  • particles: 1M
  • particle size: 0.015, random size: 100%
  • icosphere scale: 0.1
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  • $\begingroup$ The problem with this approach is that I need my environment to have volumetrics and dust. At the same time. This dust setup relies on volumetrics being set quite low, would it be possible to mix two separate volumetrics setups so I can have fog/etc and dust? $\endgroup$ – meed96 May 5 '15 at 17:43
  • $\begingroup$ @meed96 yep, you can make 2 renders, first with fog + objects + all lights etc. and the second only the dust on black. You can mix the dust in with add operation no problem. If your scene is static I wouldn't bother with this at all, google some dust textures and add it in postproduction and you will get the best look $\endgroup$ – Jaroslav Jerryno Novotny May 5 '15 at 18:00
  • $\begingroup$ I was thinking about post production dust textures, but I was afraid that would look flat, but separate renders might work. I'll give it a try. $\endgroup$ – meed96 May 5 '15 at 19:15
  • $\begingroup$ @meed96 just composite many different textures with different dust particle sizes and patterns, I am confident the result will be superior to 3d dust unless you spend reaaaly long time making the 3d dust perfect. $\endgroup$ – Jaroslav Jerryno Novotny May 5 '15 at 19:18
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    $\begingroup$ Good point, now that I think of it a lot of the best artwork I've seen used multiple approaches for a single effect. $\endgroup$ – meed96 May 6 '15 at 13:36
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For volumetric lighting

There are two basic options:

1- On your world settings you can add volume scatter and volume absorption.

enter image description here

Note that anything connected to the background surface shader will be ignored and will render black, so Enviromental textures will not work well with volume scattering (for more info read this post).

2-. Create some geometry around the area where you need volumetrics, and use volume scatter as volume for the object. This approach has the advantage of being a bit less intense to compute and you can still use the background color or environment images (like HDR). enter image description here

Watch out for a couple of things: you need to increase the intensity of your lights. To have a clean image you need to bring up the samples for rendering (in this example I used 150, but you can clean it up even further with more samples or using branched tracing and increasing the samples for the volume). Fireflies may appear so be ready to use clamp indirect option.

For selective focus you can set the depth of field of the camera to a large apterture (1.4 or less) to throw the background out of focus.

Alternatively you can use the compositor: With a defocus node you can blur the image based on information from the Z pass.

enter image description here

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  • $\begingroup$ Yeah, that looks okay, but it's missing the randomness that comes from in/out of focus dust, and random size of said dust particles. $\endgroup$ – meed96 May 3 '15 at 16:23
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    $\begingroup$ Also, looking closer, that looks like noise, not dust. If you render that til it isn't noisy you'll only have clean rays of light. $\endgroup$ – meed96 May 3 '15 at 21:03
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    $\begingroup$ Gleb Alexandrov does have a video detailing how he did the scene in question... It's all volume scattering but he does ad a musgrave texture to control the density: youtube.com/… $\endgroup$ – cegaton Jan 16 '16 at 17:50
  • $\begingroup$ Thanks for adding this, wished this was around back when I asked my question! $\endgroup$ – meed96 Jan 16 '16 at 21:37

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