Principled BSDF - SSS Radius vs Color?


(cgCody) #1

I’m in the process of switching over to the Principled BSDF from an outdated node group I created for use with Substance. I can’t seem to figure out this sub-surface business.
With the old SSS shader, you had your base color, and your scattering color (XYZ radius).
With the Principled BSDF, you have your base color, your scattering color (XYZ radius) AND a sub surface color.

So my question is, what’s with the redundancy and what is the proper usage? Should I be manipulating the XYZ radius for my scattering color, the subsurface color, or both?


(Kevin McKraken) #2

I know this is kind of an old question but I stumbled upon it while looking for something else.

If you still need/want an answer:

As far as I can tell, you could think of it like the Base Color is for a Diffuse Node, but the Subsurface Color is the Base Color of a Subsurface Scattering node and the Subsurface slider is just mixing between the two nodes.The Subsurface Radius input seems to be the only thing that affects the scattering color (aside from what ever Base Color is used), which is to be expected.

In short, it is very redundant to have the two separate values, but I assume it could be useful for somebody.
Generally, I just plug the same color value into both sockets and adjust the Radius and SSS Amount as needed.

You’ve probably figured this out long ago, but I thought I’d share since no one ever replied.

Have a great day!