BP vs C++ How to Make Audio Persist Between Levels?

Development Programming & Scripting C++
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1

I am experiencing the most vexing problem. Every tutorial you see posted basically says the same thing when trying to make audio work across levels - make a custom game instance and store the audio component there. And this works… until you do it in c++

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The blueprint nodes above work. I call the Test A Song event in the character blueprint, then swap the level and it persists. Perfect, now we know it works. Time to implement it into our c++ systems…

So inside of our header we go:

public:
	UFUNCTION(BlueprintCallable, Category = "Music")
	void PlaySong(USoundCue* song, float startTime = 0.0f);

private:
	UAudioComponent* AudioComponent;

And in the code file we go:

void UCustomGameInstance::PlaySong(USoundCue* song, float startTime /*= 0.0f*/)
{
    AudioComponent = UGameplayStatics::CreateSound2D(GetWorld(), song, 1.0f, 1.0f, 0.0f, nullptr, true, true);
    AudioComponent->Play(startTime);
}

This should fundamentally be the same thing, yet, when we change levels, the audio no longer persists like it’s blueprint counterpart. Am I missing something here?

2

UAudioComponent is not marked as a UPROPERTY macro, this can make it be garbage collected.

Also elements persisting between levels should usually be carried over in the game instance. I would probably put the audio there while travelling to another level.

3

Yeap, just needed to be marked with UPROPERTY(). Didn’t realize garbage collection would hit it while stored in the game instance because I imagined with the game instance persisting between levels it would also store it’s properties. Thanks.

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