@filibis said:
Hi Samuel, interesting plugin, nice to see PBR and Gltf related extensions 
Hi Filibis
Thanks for your interest in this plugin.
@filibis said:
But i couldn't operate normal map.
Normal map must be set in PBR Material Editor. Does this info helps you enough?
@filibis said:
And didn't understand where you put those 2 'base color' textures you provided.
Reef demo model is made of two faces, two materials and three textures:
Sea normal map texture is set on Sea material in PBR Material Editor.
Sea base color texture is set on Sea material in Materials Tray.
Sea material is applied to Sea face.
Undersea base color texture is set on Undersea material in Materials Tray.
Undersea material is applied to Undersea face.
@filibis said:
Also that would be great if you let normal map strength to be adjusted and option to add metallic & roughness maps as well if possible.
I see no problem about adding Normal map scale (strength) in PBR Material Editor.
Update: Since PBR plugin v1.2.5, normal map strength is editable and rendered 
Metallic and roughness maps must be packed in one map. So it's not easy for user...
Update: Since PBR plugin v1.2.4, metallic-roughness (packed) map is supported 