How to cast level BP trigger box to actor BP?

Hello there! Basically, I have a building SM and destroyed building SM, surrounded by a trigger box. I am trying to make it so when the player ActorBeginsOverlap, they will be given the option to press a button (‘B’) and the building will then change from the original destroyed building to the normal building. However, I am having problems with it working.

When the ActorBeginOverlap event triggers, I am casting to the building BP, which will then turn a boolean to true. Once that boolean is true, the building’s SM will change from one to the other.

I’ve had no success researching and my main issue is that I cannot find the appropriate Object wildcard when casting. I also cannot seem to find the correct way to trigger the boolean otherwise.

  1. What would my object wildcard be when casting to another blueprint with the purpose of switching a boolean to true which would then activate an event via an event tick branch in the building BP?

  2. Is there a way to code all of this by placing the trigger box inside the building BP, avoiding needing to cast between the level BP and building BP? I tried placing the trigger box inside the BP, but couldn’t find a way to trigger an actor event overlap through the trigger box.

  3. Having problems with screenshots at the moment, so hopefully I have explained myself thoroughly enough!

Thank you so much!

What you need is an interface. That way, you can easily interact with any blueprint you want.

First create an interface, called “IInteractable”, for example:

Open it and set the name of the default function to “Interact”:

In your building BP or any other BP you may want to interact, add the interface “IInteractable”:

Compile and implement the event “Interact” with whatever logic you want. In your case, will be changing the building:


Now, in your character BP, implement the B key event, which will get all actors that are currently ovelapping with the player, and if any one of them has the interface “IInteractable” implemented, then the event “Interact” will be called: