Norman3D
(Norman3D)
577
imo this problem has nothing to do with GPU Lightmass. If I had to guess, I’d say your textures are way too dark.
Double check your textures, here is a guideline of how dark “black” color in PBR textures should look like:
https://docs.unity3d.com/uploads/ExpertGuides/Dark_Dielectric_Materials.pdf