Creating and Configuring MetaSound Source Assets

Master the initial setup of MetaSound Source assets and understand how to manage audio output nodes within the Unreal Engine environment.

In this lesson, you will learn how to initialize a MetaSound Source asset and correctly manage its internal audio output nodes to bridge the gap between procedural sound design and Unreal’s audio engine.

Initializing the MetaSound Source

To begin, right-click in your Content Browser, navigate to Sounds, and select MetaSound Source. Unlike a standard Sound Wave, a MetaSound Source is a graph-based asset that executes logic in real-time. Once created, opening the asset reveals the MetaSound Graph Editor, which acts as the "brain" for your audio.

The Anatomy of the Output Node

When you create a new MetaSound Source, it is automatically populated with an Output node. This node is the mandatory endpoint for your audio signal. If your signal isn't connected to an Output node, the sound will not play, even if your logic is flawless.

By default, this node usually defaults to a Mono or Stereo output pin. If you are designing for spatialized audio, you will primarily use the Mono output, which Unreal’s attenuation settings will then position in 3D space.

[Oscillator Node] -> [Gain Node] -> [Output (Mono)]

Managing Audio Output Nodes

Configuring a MetaSound Source is essentially about routing data flows. You build your signal chain from left to right:

Inputs/Generators: Nodes like Wave Player or Oscillator create the raw audio data.
Processors: Nodes like Filter, Delay, or Gain modify that data.
Outputs: The final signal must be connected to the Mono or Stereo output pins of the Output node.

If you need to expose parameters for your UI—such as a volume slider or a frequency shift controlled by a Widget—you can create Input nodes in the graph. By setting these to Float or Trigger types, they become accessible properties that you can drive via Blueprints or Data Bindings, allowing your UI to manipulate the audio in real-time.

Remember, MetaSound Source assets are self-contained. Any processing logic you define here is compiled and run directly by the audio engine, ensuring that your sound feedback is highly efficient and perfectly synced with the state changes triggered by your UI.

Key Takeaway: The MetaSound Source is a graph-driven asset where every audio signal must terminate at an Output node to be audible, and input nodes act as the critical interface for real-time control from your UI layer.