I am curious. Is it possible to create a PBR validation material node group similar to what Substance Painter has? It would be incredibly useful for fixing up physically accurate values in PBR setups. I came across this video and it illustrates how much of a time saver it is without the need to memorize correct values while letting the artist stay creative without having to worry about things.
hmmm. So, yes and maybe no. What you can do is a sigmoid for metallic/roughness to rescale values from whatever they are to the 0-1 range. You might be able to tweak the math nodes to scale it to the listed ranges or use a color ramp to clip the values into those ranges. Doing color would be slightly more difficult, but you could figure out how to do it with mixRGB nodes or separate the channels and do it with math nodes before combining them again. It might also be viable to use RGB curves to try and produce this. Effectively all this appears to be doing is limiting the ranges (true black or white doesn’t exist in the real world, for example).