Here it is:

Exported maps from Substance Painter:
– Base Color
– Roughness
– Metallic
– Normal (OpenGL)
Update: You don’t need a Reflection map of course, it is ignored when the Fresnel Type set to Metalness.

The connections and settings:
Base Color -> Diffuse Color (Weight = 1)
Roughness -> Reflection Roughness
BRDF = GGX
Fresnel Type = Metalness
Reflectivity = 0.04 (the default value)
Metallic -> Metalness

Normal Map -> Create an rsNormalMap node (load the Normal map) and connect that to the Bump Map slot

Don’t forget to set the Color Space correctly in the file nodes.

Also turn on Alpha is Luminance where the file node is connected through the Alpha Out channel to the shader – it looks like that is not necessary anymore (Redshift 3.5).

Cheers, D