 A similar instance of things occurring that were not in the script was Ian McKellen knocking his head painfully on a beam inside Bag End, but he kept acting through it.The Art Department was careful to respect nature, considering its importance to Tolkien, such as taking plants from the Edoras location into a nursery.They would sometimes mould shapes from real rocks and bark, too, and take branches into a steel structure with polystyrene for more convincing prop trees.