Creating doorways in Hammer couldn’t be easier these days, it consists of a door frame and obviously a door within it, usually a prop_door_rotating (See prop_door_rotating).
First of all, sort yourself an area for the door to go, in this example I have used a standard wall, 128 units high and 16 thick.
The next thing is to select the door dev texture, after you have done this a few time you won’t need this, but for now go into the texture browser, filer ‘dev’ and choose the orange door texture like below.
Now that’s done, make a brush the exact measurements of the texture, they are written on it but for the sake of this tutorial, make it 112x56. If you look you will see the inside measurements are 108x48, this is the size of the standard prop soor, so you can see where we are going with this.
Now, this will act as a guide for the creation of the door. Clip (Shift-X) around the door, ensuring you leave all parts of the wall intact, do this by pressing Shift-X until it shows both brushes as solid white.
Then move you template door into place so it is flush with the wall:
Superb. Now comes some more clipping. We need to clip the template brush so that we are left with the frame. Now the best way to do this is to zoom right in close, and clip around the edges of the frame (this is shown on the texture itself) by leaving 4 units in on each clip. This will leave the exact frame, just like below:
As you can see, we are left with the frame and I have deleted the bulk of the door, this is no longer required.
The next thing to do is to optimise that frame a tad, go ahead and select one of the frame brushes and use the Vertex Manipulation tool to move the corners into the flowing position:
So it should now look like this:
Ok, we are nearly done here. Last job is to texture the door. Open up the Texture Application tool (Shift-A) and hold CTRL and left click all 3 faces of the frame. Then tick the Treat as one box, this will make applying the door texture a doddle:
Now head into the texture browser (still with the faces selected) and type door into the filter, I chose the wooden door, but you can use any kind that suits:
As you can see the door and frame are one texture, this is why we are using Treat as one. When you have selected the texture, press Apply and see if it has aligned, if not then press the L and B buttons under Justify.
Here is our final frame:
Now the finishing touch is to add a door, a prop_door_rotating will fit perfectly if aligned correctly, then you’re sorted.
Something to note is you can also make the door frame itself a func_detail, but ensure it isn’t exposed to the world, including the bottom.