void UOpenDoor::Open_Door()
{
// Find the owning actor:
AActor* Owner = GetOwner();

// Create a rotator:
FString oldAngle = "old angle = " + Owner->GetActorRotation().Roll.ToString();
UE_LOG(LogTemp, Warning, TEXT(oldAngle));
FRotator NewRotation = FRotator(0.0f, Owner->GetActorRotation().Roll + OpenAngle, 0.0f);

// Set the door rotation:
Owner->SetActorRotation(NewRotation);
}