how to make SSS parametrical fog

[kubo]

Well, with the 2.55 build Radiance mentioned that with SSS we could do fog, this got me intrigued and I started to fool around trying to figure out how to make fog. Besides many aplications it has right now I was interested in using it for the apocalypsis contest ( what's a apocalypsis worth without for or smoke anyways?), and I'm sure many of you would like to use it to also for depth or fog or smoke.
This is a simple test, but with the help of all of us we can figure out how to tweak it to great awesome results, so lets see what we can do.
The scene is a quick model with an array of pillars, a base plane and a box to depict the volume fog. I've left some pillars out to best see the effect.
The fog is an specular material with 1 IOR and a turbulence mix to control the scattering. The lighting is with an HDRI since the Sun wouldn't get thru yet. (I haven't included the HDRI since it's one I bought from Peter Guthrie, but you can use any other). Rendered in PT.
So post here your tests with this or other scene and let's make the best fog and smoke ever!

[Chris]

This i cool Thanks man!

Cheers,

Chris

[hadouken]

Dope. I'm working on a mech right now and this will help at to the dystopian vibe. thanks!

Also...would there be a method for faking volumetric light using this technique? Maybe if you self illuminate the fog??Hmm...

[bepeg4d]

thanks kubo for the inspiration, here is my attempt
i've found very interesting playing with the "scattering direction" value.
it would be wonderful to make an animation with all the values.
it's a pity that the camera can't stay inside the fog
ciao beppe

[Refracty]

Great test fellows.
Unfortunately I have no time to play with 2.55 at the moment so a quick question to you.
Is it possible to show "God Rays" with this technique - Like having sun shining in a dusty building?

[kubo]

@ chris, no prob, hope to see neat renders full of fog
@ hadouken, yeap, volumetric light was explain by roeland at the end of this post http://www.refractivesoftware.com/forum ... =21&t=9380, basically inside the medium node use the emission chanel with this same settings and you'll get volumetric light, fun to play with btw.
@ bepeg4d nice tests, I agree about the camera inside, but maybe doing a thin wall around.... more tests to do, hehehe
@ Refracty, I think it could be done if you modeled the volume of the god rays thru the hole/window and add a texture like this, the only thing is that the scene would need to be iluminated using an HDRI, besides that totally doable

[p3taoctane]

Thanks for sharing kubo
I have been playing around with trying to get a "spot-light" fall off effect for a while. I created two cones and in the past added a ramped image map to them. It worked sort-a OK but the fall off occurs not just in teh long direction but also in the short diameter of the light beam as well.. I think the SSS volumetric will help with the diameter and if I could figure out how to add a "ramp" to it either with a image or using a ramp within Octane that would be cool... just am not sure how.

I have the power of the lights way jacked up in this scene so its kind-of-rough but I wanted to share it and my idea to see if you had any ideas on how to make it better.

There are two Cones coming from the spot... I was hoping that woudl help me make one lengthwise and one diameter wise fall off. That may just be making it too difficult to render. I also turned the HDR environment way down... that also may be causing a problem.

Anyway if this inspires a better attempt.... cool. If not thanks for sharing your fog file.

[hadouken]

@ chris, no prob, hope to see neat renders full of fog
@ hadouken, yeap, volumetric light was explain by roeland at the end of this post http://www.refractivesoftware.com/forum ... =21&t=9380, basically inside the medium node use the emission chanel with this same settings and you'll get volumetric light, fun to play with btw.
@ bepeg4d nice tests, I agree about the camera inside, but maybe doing a thin wall around.... more tests to do, hehehe
@ Refracty, I think it could be done if you modeled the volume of the god rays thru the hole/window and add a texture like this, the only thing is that the scene would need to be iluminated using an HDRI, besides that totally doable

Ah, I see now. thanks! I read that post, but must have missed that last part

[gilfanovruslan]

I think something is misunderstood. Radiance said:"Absorption (and SSS) now also allows the use of 3D procedural textures to define the absorption for true volumetric 3D procedural media."

Where are 3d procedural textures? Where is TRUE VOLUMETRIC 3D procedural media?


"BTW, you can use a 3D procedural to define the scattering density in 3d space, to create clouds in an object, so if you place a large box over your scene, you can use procedurals to create real clouds or smoke/mist situations."

If there is a box over whole scene we do see nothing!

[Daniel]

He means place a box which you use as the bounds for the SSS clouds.