This map demonstrates three different examples on how to implement switchable shadows:
1. A piece of rubble casting a shadow. The rubble is a func_breakable entity and can be destroyed with the provided crowbar. When destroyed, the shadow that the rubble was casting will disappear.
2. A toggle-able func_wall_toggle. Hit the button to make the wall disappear and reappear. In the process, the shadow from the wall will disappear and reappear as well.
3. A lab door with a window. Hit the button to open/close the door. At first the door will block the light and cast a shadow. When the door starts opening, the shadow will disappear. When the door is fully closed, the shadow will reappear.