Reply To: RGB node into anything other than Base Color
The behavior of plugging a Color Output (yellow) into a Value Input (grey) hasn’t changed. Blender takes the Luminance (‘average human perceived brightness’) of the Color and uses that. This is the same as using a Converter > RGB TO BW Node inbetween. Don’t know why you get white… (maybe it’s from the (environment) lighting…
A lot of the changes in the new Principled BSDF are ‘internal”
The Specular slider has just been renamed.(Specular > IOR Level). The Sheen is completely new and much improved. Biggest user change is with the Subsurface Scattering. The Weight slider in Subsurface is like the Metallic Slider: typically either 0 or 1.
In a picture (not completely accurate, but gets you started):
