Okay, now I see what you're doing. I was wondering why you were going to have the grass through the whole thing if you were showing multiple floors; now I get it! Clever solution. The only advice I can give you is carefully consider the height of each floor and how that plays into the 'length' of the tower's shadow and the size of the trees. Right now my thinking is that the tower shadow isn't long enough in relation to the reduced size of the trees. Unless the sun's almost directly overhead, but then you have perspective issues. At least, I do.