How do you get 'this' in onOverlapBegin?

Development World Creation
, , ,
1

I have an actor with a bunch of sub-component trigger volumes. All the trigger volumes do the same thing when something hits them, so I want to use only one collision function for all of them.

However, I do need to know exactly which volume was collided with so that I can run functions pertaining to it. So how would I get the ‘this’ component inside onOverlapBegin() and onOverlapEnd()?

2

I had a similar situation, so what I did was to create a new component type that inherits from UBoxComponent called UMyTriggerComponent and added a public function to it such as OnBeginTriggerOverlap, you can decide to make it implementable by BP or not.

Then in my BP actor class where I just register and unregistered the overlap function. I registered them in BeginPlay and unregister them in EndPlay (you might want to customize where to register/unregister the handlers).

// Register all triggers with their own overlap handlers

TArray<UMyTriggerComponent*> comps;
GetComponents(comps);

for (auto Iter = comps.CreateConstIterator(); Iter; ++Iter)
{
    if (UMyTriggerComponent* TriggerComponent = Cast<UMyTriggerComponent>(*Iter))
    {
        TriggerComponent->OnComponentBeginOverlap.AddDynamic(TriggerComponent, &UTriggerComponent::OnBeginTriggerOverlap);
    }
}

// Unregister all overlap events

TArray<UMyTriggerComponent*> comps;
GetComponents(comps);

for (auto Iter = comps.CreateConstIterator(); Iter; ++Iter)
{
    if (UMyTriggerComponent* TriggerComponent = Cast<UMyTriggerComponent>(*Iter))
    {
        TriggerComponent->OnComponentBeginOverlap.RemoveDynamic(TriggerComponent, &UTriggerComponent::OnBeginTriggerOverlap);
    }
}

Adding all the other events should be easy.

3

Just to confirm: essentially a class is used to pretend everything is calling the same function when they’re in fact just calling their local copies, right?

4

What I’m doing is register a function of the component itself to catch the event and not the owning actor, the owning actor just registers/unregisters the events, this way you know exactly which component got the overlap event because the actual component will get noticed.