Roughness question...

[dayna_beaver]

Hello, I've been trying to figure out a seemingly simple thing, but I'm completely missing something. All I'm trying to do is control the amount of roughness. I've setup a very simple material with a b&w checker . So, my understanding was that 'white' areas are where the roughness is visible and black isn't.... and that the amount visible was controlled by the roughness value; 0 = nothing and 1=100%. However, with the attached images, a value of 0 is the same as 1; no change at all? What am I missing!?

[Morbid Angel]

Roughness amount is overwritten by the map value in the map slot. In order to use the value in the shader you need to reduce the map amount where the checker is plugged into the shader's roughness. Its a bit confusing and not very intuitive imho.

[dayna_beaver]

Thankyou! smh

[^Lele^]

Correct: the maps are not masks, they are drivers.
You can control roughness exactly by plugging a vrayColor into the checker map slots, and then setting both to white, and controlling roughness via the float RGB multiplier (i.e. it's in the 0-1 range.).
Values above 1.0 and below 0.0 are clamped to the normal range.