Movable object wont rotate in Unreal

Question

I am using following code to rotate an object and its set to movable in editor.

void URotateMe::TickComponent(float DeltaTime, ELevelTick TickType, FActorComponentTickFunction* ThisTickFunction)
{
    Super::TickComponent(DeltaTime, TickType, ThisTickFunction);

    FRotator rot = Owner->GetTransform().Rotator();

    UE_LOG(LogTemp, Warning, TEXT("rotation before : %s"), *rot.ToString());

    Owner->GetTransform().SetRotation(FQuat(rot.Add(0, 20, 0)));

    rot = Owner->GetTransform().Rotator();

    UE_LOG(LogTemp, Warning, TEXT("rotation after : %s"), *rot.ToString());
}

Can someone help me see what I am doing wrong, since I am new to Unreal Engine.

Answer 1

First of all, check that in your BeginPlay() method, you have

AActor* Owner = GetOwner();

Otherwise UE won't recognize the Owner pointer in FRotator rot = Owner->GetTransform().Rotator();

Also, for Owner->GetTransform().SetRotation(FQuat(rot.Add(0, 20, 0))); I suggest staying away from FQuat as a beginner since Quaternion references can be a little weird. Try using the SetActorRotation() method (which by the way has multiple signatures, including FQuat() and Frotator()) so you can do something like this instead:

Owner->GetTransform().SetActorRotation(FRotator(0.0f, 20.0f, 0.0f));   // notice I am using SetActorRotation(), NOT SetRotation()

Or even better, this is what your code should look like in your BeginPlay():

AActor* Owner = GetOwner();
FRotator CurrentRotation = FRotator(0.0f, 0.0f, 0.0f)
Owner->SetActorRotation(CurrentRotation);

and then your TickComponent():

CurrentRotation += FRotator(0.0, 20.0f, 0.0f)  
Owner->SetActorRotation(CurrentRotation);      // rotate the Actor by 20 degrees on its y-axis every single frame