In fact two , very simple : - can we add a floor to the scene (there is a ground, not a floor, the difference is the ground should be seen through the window). Meaning of the question is : a floor could be considered as an object (like a square or a disk). I know it seems a dumb question -lol - can we add a roof (yes it's very similar to the previous -lol). But in the case of the scene, the roof, not seen by the wamera, will change the lighting distribution (outdoor/indoor) Sorry to ask these basics questions, ;=) Yves