Mistake in Substance Painter to Arnold Documentation

[defaultmjv1qu1pvfjc]

On the page here: https://substance3d.adobe.com/tutorials/courses/Substance-guide-to-Rendering-in-Arnold

The chart at the start describes that the opacity map from Substance Painter should be connected to the aiStandardSurface "Transmission Weight" value (RAW + Alpha is luminance). This is incorrect according to the documentation described further down the page...

The correct connection should be to set the Transmission Weight to 1, and connect the Opacity texture to Transmission Color.

I hope this helps people out there!

-Michael

[defaultmjv1qu1pvfjc]

Correction: I found that it does work best if you plug the Opacity map from Substance Painter into the Transmission Weight. I'm not sure why the documentation below that suggests that it should be plugged into the Color. Perhaps someone could chime in here with a good explanation.

Thanks!

-Michael

[puchingball · Accepted solution]

I think you are missunderstanding this, the opacity map exported from substance i think is a b&w map, so, it must be taken as it is baked, so raw + alpha is luminance takes it's values without any modifications, in the other hand, i don't see the document saying that it should be placed on the color chanel of transmition, it states that should be placed on the material geometry  - opacity value.

The main difference between arnold transmission weight and arnold geometry - opacity is that weight just makes transparency appear but the base color still remains even in 0 value, and geometry - opacity defines the object % of visibility, at 0 object acts like hidden.