This Map shows how to make a Metroid-Like Iris door for half life one.
On one side, you can open the door by just walking towards it, on the other side, you have to shoot the shield in order to open the door.
trigger_multiple triggers the func_button which triggers the func_door_rotating's
Only one piece of the door has sound attached it to avoid overwhelming the sound system when it opens.
Will credit ya of course!