This page explains how to create a rotating door in a Counter-Strike map with Hammer. Here is the basic set up:
First, build your door however you want it to look. Use as many brushes and textures as you like.
Then you need to place a special brush called an ORIGIN brush. It is the green brush in the picture. It is used to set the 'center' of your door. Your door can only rotate around its 'center'. You can set the center anywhere, even outside the door.
The blue line shows what the door will rotate around: the Z Axis which goes through the center of the ORIGIN brush. If you do not use an ORIGIN brush, your door will rotate around the center of the map. Which is bad.
Once you have your door and ORIGIN built, select all your door brushes and your ORIGIN brush and press Ctrl+T to 'Tie it all to an Entity'.
There are a few properties you must set now, like how fast your door opens and how far it opens, etc.:
|Speed||The default is usually ok but you might want to make a fast or slow door.|
|Distance (deg)||How far your door opens, 90 degrees by default. Usually this is correct.|
Also take a look at the flags:
|Reverse Dir||Makes the door open in the other direction. Same as using -90 instead of 90 for the distance (but safer?)|
|Passable||Makes the door non-solid, so you can't be blocked by it.|
|One Way||Makes the door only open one direction. Otherwise you can push the door open from either side.|
|Toggle||The door will not close by itself, you will have to use it again to close it. Probably more realistic.|
|X Axis||Makes the door rotate around the X Axis. Good for a trap door with the hinge on the North/South edge.|
|Y Axis||Makes the door rotate around the Y Axis. Good for a trap door with the hinge on the East/West edge.|