Two explanations: 1) if these objects have vertex-based lighting, then it means u need to adjust your smmothing groups in your 3d app. Smoothing grouops applied to the mesh should be in a sequential order (e.g. 1, 2, 3, 4 etc., but NOT 1, 5, 12, 2 etc.). 2) if you use actual UV unwrap to have lightmap baked into these…