@Mihai - well . in Substance it is a percentage from 0 to 100
that could be added to any layer. For instance if you wanna have materials like a "Jet-Metall" - or simply material that have meatless and refraction .. hmm .. like a sunglasses
but you right - in majority of cases it goes pretty shard black and white - but generally - greyscale.
And well . in Substance you do defying "Metalicity" of a certain layer in your material layer stack.
You can easily try this: make a super shiny plastic that has a base texture, vs make a metal with the same texture. The reflections should not blend in the same way with the texture. And there is no physically based instance when this metal behavior "blends" with a plastic behavior *in the same physical material*.
- Yeah - this is the first thing I tried in Maxwell. Well, again, they don't have to be in the same material, it could be a plastic coated with metallic paint that was scratched away but not fully, not in all area ... for instance that could be observed on Christmas toys
those a rare cases of course.
I'm not really into PBR much, at this point, I would rather use Substance as a texturing tool.
Substance Designer says instead that, you can have small values of "metallic" to describe a dielectric (I'm not sure, but I'm guessing from a physically correct view, this doesn't make much sense), or stuff that's above a metal surface, like dust.
- If only software could tell us something
) right ? Well - you're right, PBR workflow was designed for GameDev mainly. And in their case for metal-rough shader for non metallic surfaces they used 0.04 value - which was a mid grey in linear mapping from 0.0 black to 0.08 white. Almost unnoticeable unless you have a very pronounced spec map, but it is there.
) And it make sense .. however from Physically correct point of view - the entire PBR is just like you said - buzz words
It seems to me what I would do (in the case of working with Substance Designer), is use this metalness mask as an inverted layer mask for any dielectrics you may have on top of the metal. So your grey areas in this metalness map will represent areas where paint or other insulators are partially faded away which is what they are saying anyway on that page.
I think the confusion comes when trying to use one map to define reflectance values for two wildly different materials - which seems to me you would need higher than even 16bit images to properly account for the range of possible values. Instead, avoid confusion and think of this metalness map as simply a mask, between two distinct and separate material types.
- totally agree here. That how I used it also. The reason I posted it here is if someone would wonder on "how to" -
Carpaints is a bit of a special case because there are metallic flakes suspended in an insulator. I don't think you'll be able to convert a car paint shader done in Substance to work the same way in Maxwell, just using masks. The metallic flakes need to be "in" the paint and you can do that using a flakes normal map, and a BSDF mask for a metallic BSDF. That works very well actually (I'm almost finished creating a few carpaints this way).
- Oh man - I've seen those - they are awesome!! Have to admit - I'm quite jealous there
Well, anyway - this is a WIP thread, so I'll post more tests once I'll have a bit more time.