Think of triggers as machines. When you execute a trigger, the trigger will do stuff. It can open doors, teleport players, show text, etc..
The things a trigger do depends on what instructions you gave the trigger.
The instructions are known as trigger action. A trigger can can run 10 instructions (trigger actions) at once.
Let's now try to open a door.
To open a door, we need to run the trigger action that is responsible for moving a door.
Reference:
https://www.plazmaburst2.com/level_edit ... orial&a=#_
First, we create a movable and a region. Place the region below the movable. Make sure the region is the same size as the movable. Now place a trigger.
Click the 'Do nothing' area
After clicking that area, you should see a long list of trigger actions. Click the trigger action that says
Movable > Force Movable 'A' move to region 'B'
This trigger action will move a movable to a region. It will move movable stated in Param B and move to a region stated in Param B.
After that, you may see that parameter A and parameter B is automatically filled up.
It's not a good practise to let the parameter's auto select, so let us manually select the door and region.
Click the area beside Param A, and you will see a red circle around your door*1. Hover over to the red circle and click on it (it will turn green). You selected door*1.
Do the same for Param B, but this time clicking the region.
You have your trigger fully set, but the trigger will not run the instructions on it's own.
Remember, you need to execute the trigger for it to do stuff.
So, let use create a USE button to execute the trigger.
Create another region. Select 'USE key (with button)' for Activation on. Hover over and select the trigger you created.
This region will execute the trigger when you press E, which causes the trigger to perform it's trigger action.
It will move a movable to a region. Save the map and test it.
Summary
1. Trigger run trigger actions, which do stuff.
2. Trigger actions takes in Parameters to tell the trigger action who to target.
3. We need to execute a trigger for it to run it's trigger actions.
So how do I close a door?
Create another region, set it to USE key and set it to activate another trigger, which uses the same trigger action. Create yet another region and place it on the door itself. Set the Param A and Param B accordingly so that it moves the door to it's original position.
Set the trigger's max call to Infinite so the trigger can be used again and again.
I hope you can see the pattern and understand how triggers work now.
Trigger actions explanation can be found in the manual provided by yi en:
viewtopic.php?f=126&t=23938