I needed to create a city so I downloaded an asset "Buffalo City 1980" .skp file, opened it in SketchUp, exported it to .obj (worst output), .fbx and .dae (much better). The collada file at least renders rectangles correctly otherwise they were transparent in other formats. But textures are still not rendered as in SketchUp.There are all textures and materials. I am importing correctly with all the folders yet this is happening. I also set 'calculate' in normals settings in import, changed the shaders, as mentioned in in this solution but no luck.
Somebody in this post said sketchUp is not good for game engine assets. Any ideas why this is happening, or if I even should use sketchUp for these purposes at all? I will be needing to add colliders (box) later, hope it will be same as doing on the models imported from 3ds, blender etc.