Messing with the absorption layer transmittance parameter.


In the sss version, notice how the blue scatters below the surface - its a thing of beauty & wonder!

The sss version is darker, but I assume that is from the scattering,
since I've never been able to get a pure white sss material.

Wow, cool test.
If anyone is interested, absorption layer transmittance is perfect for creating things like imperfections on human skin (freckles etc..), when applied to a glossy transparent material. hint hint.

Very cool !

skin test...needs tweaking but looks promising I think.

Promising!
Could you give us your sourcecode?

I didn't save the IGM and now it's lost. However, these are the settings from what I recall:

Glossy Transparent
IOR=1.08
Exponent=50 (I think)
Absorption=?? (almost white, relatively low)
SSS=Uniform 300
Abs Layer Trans=Skin texture downloaded from internet with gamma=1.0 (makes it brighter)
No bump map for this test

I think that playing around with the absorption will result in different skin tones. I have no idea what the scattering value should be for skin. 300 might be too low but high SSS values really slow down Indigo so I don't like to go above 300.

Thank you!

Can't wait till fused implements it into Cindigo...

Then you'll be glad to know that he already had implemented it

nice one Whaat.
However, I would recommend that the absorption layer transmittance texture only have surface-level colours, such as freckles etc.. The general pink (or equiv.) colour of the skin should come from the medium absorption colour, as in real life.

Yeah, I did
I need to get that mac build out!

Ah, that was the point...!
Jetzabbazackzack!

Realy nice test

awesome! what's your sss material settings?

Thanks everyone!


The absorption is 0/0/0, scatter is uniform 300 & phase is uniform.
The texture itself was 255/255/255 white with a 0/0/255 blue bar,
used as the absorption_layer_transmittance in a glossy_transparent material.

When I rendered it in the material editor, I got a lot of fireflies, but
rendering with metropolis true and bidirectional & hybrid false cleared it up.

I hope that helps!

Made this for an example.
23 hours rendering with Nick's i7 as slave