KeyShot Forum

Technical discussions => Post-processing => Topic started by: Eugen Fetsch on August 26, 2018, 12:53:20 am

Title: Passes
Post by: Eugen Fetsch on August 26, 2018, 12:53:20 am
Is it possible to integrate the pass for scattering medium?

A "UV Pass" would be great too!
Title: Re: Passes
Post by: Rex on August 29, 2018, 09:56:24 pm
Hi Eugen,

What are the results you expect to achieve with a "scatter pass"? Can you provide an example of what this would look like?
Title: Re: Passes
Post by: Eugen Fetsch on August 30, 2018, 07:24:41 am
Hi Rex,

actually I don't really know if it's even possible to create such a pass. :-\

I've thought to use one of the available passes for denoising + final color adjustment in the compositor and couldn't find a pass that is useful. That's why I've asked. 

The AO and Diffuse passes are empty. The Clown Pass, Shadow Pass and Depth Pass show the base geometry (cube).

Title: Re: Passes
Post by: Rex on August 30, 2018, 08:26:39 am
Good points. I definitely see the benefit. Maybe we can detect areas outside of a vdb  with 0 density to at least have the correct silhouette.

I'll inquire with dev to see what's possible.

Thank you
Title: Re: Passes
Post by: Eugen Fetsch on August 30, 2018, 09:38:04 am
Sounds like a plan :) Thanks!
Title: Re: Passes
Post by: bdesign on September 04, 2018, 07:57:31 pm
Hi Eugen-

You can create your own Scattering Medium pass with the following procedure:

1. Set the Scattering Medium Transmission and Albedo to black.
2. Set the Environment Background Color to white, and turn off Ground Shadows.
3. Render image and then invert.

The example images below are quick renders at 64 samples each. They are:

1. Bunny VDB beauty render.
2. Bunny VDB mask render.
3. Bunny VDB mask render inverted in Photoshop.
4. Result of mask used as Layer Mask with a Hue/Saturation Adjustment Layer applied to Bunny render.
5. Smoke VDB beauty render.
6. Smoke VDB mask render.
7. Smoke VDB mask render inverted in Photoshop.
8. Result of mask used as Layer Mask with a Hue/Saturation Adjustment Layer applied to Smoke render.
9. Result of mask used as Layer Mask with a Gradient Map Adjustment Layer and a Hue/Saturation Adjustment Layer applied to Smoke render (also used to mask out and change the background).

Hope this helps :)

Cheers,
Eric
Title: Re: Passes
Post by: Eugen Fetsch on September 05, 2018, 01:20:58 am
This is a good workaround till the pass is implemented. Thank you.
Title: Re: Passes
Post by: DMerz III on October 01, 2018, 09:03:49 am
 :) Eric, you're the champion of solving puzzles. Thanks for sharing your wisdom once again
Title: Re: Passes
Post by: bdesign on October 01, 2018, 04:40:16 pm
:) Eric, you're the champion of solving puzzles. Thanks for sharing your wisdom once again

Aww, man, you're too kind, David :) Thank you!

Cheers,
Eric