Ah, I think I see what you mean now - the lighting is wrong where the tiles join?
If so, I dont think flatshading will help, TBH. It isnt properly implemented in B3D. Instead, just make sure the norms at the tile edges are pointing straight up, instead of having them smoothed.
If so, I dont think flatshading will help, TBH. It isnt properly implemented in B3D. Instead, just make sure the norms at the tile edges are pointing straight up, instead of having them smoothed.