Metalness other than 0 or 1 ?

Cos_Dim

Hello!
Here's a question that came to me while going through some articles about PBR:
In what cases, can the Metalness input be different than 0 or 1? Like 0.5 for example.

If you can think of any cases please comment them so that we can all learn something new!

EarthQuake

Check out this thread: http://polycount.com/discussion/171689/pbr-the-problem-with-greyscale-metalness

Cos_Dim

Thanks for the pointer, @EarthQuake !
It seems that there is not really a reason to have any other value in metalness.
Kind of a downer really. I'm still hoping someone can find some way to surprise us!

Zack Maxwell

I toyed with it, and it had a nice effect with certain organics, like a slimy or gelatinous surface, or certain liquids. Not sure how physically accurate it is, though.

Valandar

Umm... yes, there IS a reason. If a given substance has a granular nature, where a single texel would cover numerous metallic and nonmetallic particles. When a simplistic shader is required but the material would be one with a layer of nonmetallics over a metallic. An anti-aliased line where metal meets non metal. Just to name a few, of course.

ZacD

Sometimes it's nice to play around with on transparent materials, depending on how you want the reflections to look.