How to make a basic door in Garry's Mod

One of the unique things about Garry's Mod is the ability to make your own objects in the game and to have them function. This video shows how to make a door that will open and close, making use of axis constraint, buttons, and hydraulics. You can use this information to make a far more powerful object in the game.

The best way to learn how to create cool objects in Garry's Mod is to play around with things until you find something you like!