Add moving doors to your elevator model

Take your elevator model and add moving doors. Divide the front of the elevator into four horizontally equal sections, panels from floor to the top of the opening. The two outside panels are part of the elevator. The two inside panels are the doors. They move vertically with the elevator. They open horizontally by splitting in the middle and moving outward, overlapping the side areas. They close by moving back together. The doors should be simple solid surfaces, of a different color than the elevator itself. They do not need to have a thickness. When opening they can occupy the same space as the fixed panels beside them, but they should be drawn after the elevator so they always show on top of the elevator. Make the entire elevator and shaft wider if it helps to see the doors.