when the animation of the chest play open and you spawn the items set the gravity of the items to ie 400 place a timer o += item.gravity*Timedelta to each item then slowly in time increase the gravity of the items then when items collide floor stop
when the animation of the chest play open and you spawn the items set the gravity of the items to ie 400 place a timer o += item.gravity*Timedelta to each item then slowly in time increase the gravity of the items then when items collide floor stop