Place props

We need a prop type that can allow parenting, so add a new prop_dynamic to the map. Now find a model that suits your need. I am going to use prop_gameplay/door_grate003. For the moving parts, I am going to use the top and bottom model.
To start this tutorial off, I’m going to place them vertically.


I am going to cover 3 “types” of these bi-directional gates: up and down, left and right and one way (close behind you).

Open Up and Down

With the 2 prop_dynamic gates in the map, we are going to give them a name. Keeping it simple, “gate1bottom” and “gate1top” will do.


We will have to come back to these prop’s properties in a bit.
These props do not have any animation tied to them. If we want them to move, we will need to parent them to something. We are going to use a func_door to act as the thing that will move the prop.
First, find a metal texture. The only reason I suggest using a metal texture is so when the gate takes fire, it will reflect the sparks you would expect from metal on metal.

Make a brush that encloses the top gate prop. Try and get it to be as close to the same height as you can. Width is not as important for this type of gate.


This brush will be acting as our func_door for the top gate, so let’s make it a func_door! Press CTRL + T and select func_door (one down from func_detail) then press apply. We will need to name this door, I think “gate1topDoor” will work just fine. There are a few setting we need to touch up as well…

Render Mode: Don’t Render (makes it invisible)
Disable Shadows: you might want to
Speed: 300 – 400+ (you may want to play around with this one)
Move Direction: Up (-90 0 0)
Under the Flags tab, uncheck Touch Opens and check Toggle.


Now go back to the prop_dynamic for the top gate, and add “gate1topDoor” to the Parent property. This will tie the movement of the func_door to the prop.

Before we move on, do the same thing to the bottom gate. The only difference is instead of an Up move direction, make it down (90 0 0). Not that complicated just yet!

Now we need to set the area where players will trigger the gate to open and close. Select the Trigger texture and make a brush surrounding the gate where you want players to be able to open the gate.


With the trigger brush selected, press CTRL + T and select trigger_multiple.

I gave it a name of “gate1Trigger.” Pop over to the Outputs tab, we have some work to do there. Click Add..

Output named: OnStartTouchAll
Target: gate1bottomDoor
Parameter override: Open

Add…
Output named: OnEndTouchAll
Target: gate1bottomDoor
Parameter override: Close

Now do the same for the top gate. The only thing that changes is the target.


Now would be a good time to compile the map (press F9) and make sure the gate opens and closes. Also, make sure to tweak the speed of the func_doors if needed.

Left and Right Sliding Gates

Start off by placing the props rotated in a way that you want.


Follow the same steps taken to make the up and down gates. The only difference is the move direction.

The best way to figure out what direction to move the func_door (since there is no left or right options) is to view the map in the top view. If you use the angle chooser, it will be easier to figure out what way you want the door to move.


Once you have found the correct angle for one of the gates, the other will just be the opposite!

One way, no return!

Once you have a gate that works, to make it one way all you have to do is move the trigger_multiple brush.


One very important thing to remember about these gates: they do not disappear when they are open. Unless you want the gate to be exposed when it is open, you should cover the sides where the gate will open to. There are a few gate models that have animation tied to them so they will not show when opened. But with those, the func_door will still be solid. There is not much that can be done about that. One day take a trip to cp_dustbowl and stand on the edge over Red’s spawn on stage one. If a player opens the gate and you are standing in the correct spot, you will move up with the gate.

I have included an example map with these three types of gates. You can grab it here.

If you have any questions, need help, or just want to talk, hit up our forums!