Tech Assist - Closing Doors


I created a cargo hatch and automated it to open using a box trigger on a wall panel and a matinée scene. For now, the trigger is impact oriented (I would prefer it to be key activated, but that I can figure out). Unfortunately, I can open the cargo hatch but it will not close. I think I need to define another box trigger and set it to reverse. I’d like to close the hatch using the same panel used to open it (1 hit to open and another hit to close). Can anyone link me to an information source explaining how to do this or detail how to accomplish what I need to do.


Use a “FlipFlop” node -> connect the first link with the play node and the 2nd one with the reverse node :slight_smile:

I searched google for a how-to on a “flipflop” node. I’m not coming up with anything. Could you either explain more in detail or link me to somewhere I can read more about it and how its created?

I found documentation for flipflop nodes under flow control I followed the process but I think I’m missing the logic. Posted is what I have. I can see that I’m missing an element to reverse the cargo door. I assumed that Reverse would go between OnActorBeginOverlap and the FlipFlop node or after the flip flop node and before Play, but I was mistaken. Any help is appreciated.


You need OnActorEndOverlap that is connected to the Reverse node as shown here: Toggle play then reverse Matinee on button press - UE4 AnswerHub

A flip flop node alternates between return node A & B, A should play, B should reverse.

Thanks the diagram really did the trick. Being somewhat new, I think I over thought the problem.

Hi Wranglerltg,

I see you found a answer. Additionally, you can use a simple flipflop formula with a variable: [FONT=courier new]1-n=n
Assigning [FONT=courier new]n=0 on initialization, the formula produces the following:[FONT=courier new]1-0=1