Allways an object with greater number will be displayed over an object with smaler number in a room ? Eg: obj 4 will be displayed over obj 1 ?
No. By default, whichever object's bottom y-coordinate is lower (further down) gets drawn in front. If you can't move the object, you can change that by setting specific baselines in the editor. The object with the lowest (further down) baseline gets drawn in front.