MetalsDielectrics/Roughness: Vray Next

[DanSHP]

Hey, I'm now on Next. Using scans with Roughness maps. Want to follow correct method setting up materials so, ignoring bump....

...how i set up materials before and now after upgrading.

Metals
Vray 3.6 Glossiness
Diffuse Black
Fresnel off
Falloff in Reflect
- Base reflectivity colour (vray colour) in first falloff slot together with any glossiness maps in a composite map
- Bezier curve in Mix curve
Control Glossiness highlights 0.65 upwards etc

Vray Next Roughness
Diffuse, Base reflectivity colour
Reflect, full white
Fresnel on
BRDF ensure roughness selected
Roughness maps in Roughness
Metalness, change to control glossiness of material*

Dielectrics
Vray 3.6 Glossiness
Diffuse, colour or texture
Reflect, roughness map inverted, or full white colour if no maps used+
Glossiness, gloss map
IOR, change if necessary in refract to control Fresnel

Vray Next Roughness
Diffuse, colour or texture
Reflect, full white colour
Roughness, roughness map
IOR, change if necessary in refract to control Fresnel
BRDF Roughness selected*

I was never sure my scans were working correctly in 3.6 as it didn't support roughness in the way Next does now. I just want to be certain I'm doing this correctly now that I have all these scans and to update my library accordingly.

My question is. What is the (using roughness) best way to control glossiness highlights?

If I want a chrome I set metalness spinner to 1? If I want flat aluminum to 0.5? Or do I control this with the roughness parameter spinner?

[hermit.crab]

The 'Metalness' parameter should be either 0 or 1 (either a Dielectric or a Conductive material) since its idea is physical accuracy (there are no in-betweens in the real world in terms of metalness).

Hence, controlling the glossiness of the material, in your case, depends on the roughness parameter (which is equal to 1/glossiness).