In Blender, link item 'NodeTree/glTF Metallic Roughness' or 'NodeTree/glTF Specular Glossiness' from the glTF2.blend file. gltf2_Principled.blend is for Blender 2.79 and later versions.
More on this can be found in the user documentation.
This repository has been archived by the owner on Mar 28, 2019. It is now read-only.