Best way to create a pbr Specular/Roughness shader?

[chrissie912]

Hey guys,

I'm using Substance 3D Painter proffessionally, but a big hurdle for us the that our shading model utilizes a specular colour/roughness workflow. 

Ideally I would like to take the specular/gloss shader and simply replace the glossiness parameter with a roughness one. 

Is this difficult/possible to do? What would be my best course of action seeing as I do not have any glsl experience? 

[Half Life]

The best answer I've found on this (short of biting the bullet and learning glsl) is the MaterialX plugin for Substance Designer. However, that is still in beta and does not support the latest version of MaterialX (among other issues).

You can download it here: https://share-legacy.substance3d.com/libraries/6111