Roughness map looks shiny unless I turn off alpha is luminance?

[50029262]

My material looks shiny whenever I plug my roughness map into spec roughness in the hyper shader. I have it set to raw and originally had alpha is luminance ticked but this makes my character look very shiny and metallic. Have I exported it from substance painter wrong possibly? 

[Kahylan]

Hi!

Thats because you connected your Metalness, Specular and Normal to "outAlpha" of your texture maps, instead of connecting them to "outColorR". Alpha is a value that is stored within the pixels of formats that support transparency (png, tif, psd, exr, etc) to tell the computer how translucent a pixel is.

Your Spec, Roughness and Bump map don't have any transparency, so the alpha map of those texutres is just solid white on every pixel, thats why your texutres turn out too shiny. Thats why you connect those maps to a single color channel.

I know it seems weird to connect a grayscale map to either "outColorR", "outColorG" or "outColorB", but for the computer grayscale values are just RGB values with the same number on each color channel (e.g 50% grey = (126,126,126)) so it doesn't really matter which color you pick as Arnold will just look for where between 0 and 256 that value is.

I hope it helps!