Advanced Metalness in Marmoset 3

Zelfit

I just noticed this new option in Reflectivity in Marmoset 3 and cant find any info how to use it. It has Metalness channel and some additional Specular Level map. How should I use that Specular Level and what benefits it gives?

EarthQuake

The advanced metalness model can be used if you want more control over the specular values for insulators (non-metals). With a standard metalness map, insulators (black in the metalness map) have a fixed reflectivity of 4%. This works well for most cases, but some surfaces like skin (2.8%) or gems may need different values.

The specular input for the adv metalness workflow maps 0-1 (black to white) as 0% reflective, to whatever value you have in the specular slider. By default this is 8%, so a 50% gray in your spec map will give you the standard 4% reflectivity. This is basically the same as the specular input in Unreal 4, and I think they use 8% as the cap for reflectivity when using that map as well.

We left specular in as a user defined variable because some engines, like the Snowdrop engine I believe, use a baseline of 16%.

The specular map can also be used for specular occlusion.

Some more info in it here in the specular section: https://docs.unrealengine.com/latest/INT/Engine/Rendering/Materials/PhysicallyBased/