Hi, im importing some models from a unity3d Pack that i bought time ago. They comes with Diff and Normal map so i converted into FPSC And here my results:

PBR with Diff and Norm only:
PBR with Diff, Norm, AO, gloss, metalness:
PBR (shadow side) with DIff and Norm only:
PBR (shadow side) with Diff, Norm, AO, gloss, metalness:
PBR Comparison (Left full texture and right only diff and norm):
PBR Comparison (shadow side, left diff and norm only, left full texture):


if i Invert color in Gloss map the 2 entity are quite the same. Here a file with the texture if u can explain me where im wrong (im using shader map 4) With "Sample" cuz i can't share.

http://www.mediafire.com/file/kh6sxmgq6cb31yr/Sample.7z/file

PBR shader makes use of unreal work flow, and uses the following maps, _color _albedo _normal _roughness and _metalness. In gameguru we call our _roughness a _gloss, unity has a smoothness map, this map is the opposite of a roughness map, in unity the map with white pixel dictate how shinny the object is, in Gameguru black pixel dictate how shinny an object is. Inverting the smoothness map isn't going to give you exact results. It's best to rerender that map.

That said any models using the PBR shader will always need a min of AO, Normal, gloss, color and metalness. If you don't have all those maps present you will have rendering issues.

Some thing to note, due to the way the engine renders textures and lightmapping it's advised not to have a dark albedo. In your case the texture is pretty dark and not ideal, the metalness seems odd and looks "plastic".

I'll need to understand more about texture gonna try more!