Implementing Spatialization for Procedural Audio Sources

In this lesson, you will learn how to configure your procedural MetaSound graphs to respect 3D space, ensuring your generated audio behaves like a physical object in your game world.

The Role of Spatialization Nodes

When you generate audio procedurally—such as a humming energy field or a synthesized engine—the MetaSound acts as the source. However, by default, these sounds are often treated as "non-spatialized" or "stereo," meaning they don't change based on where the listener is standing. To place them in 3D space, you must leverage the Spatialization plugin integration within your MetaSound graph.

The primary node you will interact with is the Spatialization node (often handled via the Source Settings inside the MetaSound asset). By enabling "Spatialization" in the MetaSound’s graph settings, you tell the engine to treat the output as a mono signal that can be positioned.

Implementing Attenuation

For the sound to feel "procedural" yet "physical," you need to link the MetaSound to an Attenuation Asset.

1. Create an Attenuation Asset in your Content Browser to define how volume drops off over distance.
2. Inside your MetaSound graph, ensure your output is set to Mono. If you send a Stereo signal into a spatialized source, the engine will downmix it, often leading to phase cancellation or unexpected panning issues.
3. When you spawn your MetaSound via an Audio Component in a Blueprint, assign this Attenuation asset to the component:

// Within your Blueprint Logic
AudioComponent->SetAttenuationSettings(MyAttenuationAsset);
AudioComponent->SetLocation(SpawnLocation);
AudioComponent->Play();

Positioning Logic

Because your audio is procedural, you might want the sound to move dynamically as it generates. By updating the SetWorldLocation of the AudioComponent while the procedural engine is running, the spatialization engine continuously recalculates the panning and distance-based filtering (like Low Pass Filters) defined in your Attenuation settings. This ensures that as your grain density or frequency modulation changes, the "source" remains anchored to the correct point in the 3D environment.

Key Takeaway: To spatialize procedural audio effectively, ensure your MetaSound output is strictly mono and pair it with a dedicated Attenuation Asset via an Audio Component to handle real-time distance and directionality calculations.