Questions on Random Walk SSS Tweet

[Notiusweb]

Random Walk SSS -
i am just not sure how one is to use this:

If we have a Universal Material, with an Albedo map, and we want to use the Random Walk SSS,
do we set a
(1) color in Transmission and then
(2) also place the same albedo-texture in the albedo-slot in the in the Medium field?

No matter what combo I try Bias doesn't really seem to do anything, other than raise or lower the color in Transmission....
But it's like Transmission already could do this by itself, you know?

Just weird, the sample scene had solid white color, no actual textures, so it didn't really show you how a texture map would fit into it.

THX!

[Despot]

Works for me, just make sure your albedo is set to black... see screendump.

Hope this helps...

J

[Notiusweb]

Hey D-Man,
thanks....
Ahhhhh...Black Albedo....Thanks for leaving that out, Otoy...

Actually, now when I try it out, I can see why it wasn't really shown off. For a character, it works pretty bad compared to a traditional means of using Transmission for SSS.
But, it can make pretty good ghost-like materials without using opacity.

Or easily concoct a race of delicious candy people! I guess that is cool, I guess.

Anyway!
Thanks and good times!

[nejck]

I could be wrong but isn't SSS via transmission alone just a fake SSS?

[J.C]

Hey D-Man,
thanks....
Ahhhhh...Black Albedo....Thanks for leaving that out, Otoy...

Actually, now when I try it out, I can see why it wasn't really shown off. For a character, it works pretty bad compared to a traditional means of using Transmission for SSS.
But, it can make pretty good ghost-like materials without using opacity.

Or easily concoct a race of delicious candy people! I guess that is cool, I guess.

The attachment CandiedLand.png is no longer available

Anyway!
Thanks and good times!

Have you increased medium density? Here are some of my experiments I did earlier where it is set to around 300-400:

[Despot]

@ J.C

Cool renders - would you be able to post screendumps of the settings you have for the shader, I'm specifically wanting to know if you are using a map to control 'radius' or are you using a colour ?

Thanks

J

[J.C]

Sure, here is my material setup:

Material:

Medium details. Here I'm using color for radius:

Diffuse details:

[fantome]

thanks for sharing your very realistic sss setup !

[rudigude]

Hi! Thank you for sharing! Looks like an "Arnold class" skin shader now.

[Notiusweb]

I am pointing this out in the main Dev Build forum now, there are many issues in using this technique, especially if your body has multiple textures:

1) Using to high saturation in Radius causes Hot pixels
2) Leads to a simultaneous 'darkening' of the underlying Albedo edges, making it look like a pencil-line between textures
3) Renders black in Daylight kernel mode (in other words, is completely dependent on Path Trading)

It's a shame really, because it responds excellent to HDRI lighting. Much better than 'regular' Transmission use does.
Just too many side effects ruin it.
For a single Bust mesh with closed eyes, though, is awesome on skin.
But with open eyes, no good