This is a very relevant question. The principled BSDF has fresnel built in *for the metallic/specular values* but NOT for the roughness value. I'm not sure why this is the case but this video from Chocofur covers this well. Still I use the built in fresnel effect 90% of the time and never use the node group anymore.
As for the Beers-Lambert absorption group, I don't think it's compatible with the principled BSDF. Meaning I don't believe the principled BSDF can be manipulated to achieve the same effect. I would still use the node-group.
As for the Beers-Lambert absorption group, I don't think it's compatible with the principled BSDF. Meaning I don't believe the principled BSDF can be manipulated to achieve the same effect. I would still use the node-group.
Is there anywhere on the net that I can download this node group? Looking to give it a try.
Yes you can download the nodegroup here. This video explains the internal components and this video demonstrates its usage.
