Audio Event Graph

The Audio Event Graph is a visual node-based editor for authoring complex sound events. Instead of a single clip pool, you connect sources, filters, effects, and routing nodes into a graph that evaluates as a data-flow pipeline. Each .audiograph file is one sound event. At runtime, the graph maps directly to a live audio processing chain.

For component properties and C++ extension, see the Framework API reference.

Contents

• How It Works
• Phase Lifecycle
• Nodes
• Using Variables
• Playing at Runtime
• Quick Reference
• Glossary
• See Also

How It Works

Nodes in an Audio Event Graph evaluate left to right in topological order. Connections carry AudioRoute values — handles to a point in the audio processing chain. The signal flows through:

1. An Entry node gates which phase is active
2. Source nodes create and output audio
3. Filter and effect nodes process the signal
4. Routing nodes (If/Switch) direct the signal based on variables
5. The Output node wires everything to a mixing bus

Only nodes affected by a change re-evaluate — the rest are skipped. This makes variable-driven sound modification cheap even for complex graphs.

Phase Lifecycle

Every Audio Event Graph supports up to three phases:

Phases transition automatically: Start fires once, Loop repeats while looping is enabled, Finish plays when FinishAudioGraph() is called. Not all phases are required — a simple one-shot only needs Start.

Entry nodes share routing freely. A source wired to both Start and Loop phases produces sound in both.

Nodes

Source Nodes

Both support volume, pitch, delay, looping, and 3D spatialization.

Filter Nodes

LowPass, HighPass, BandPass, Notch, PeakingEQ, LowShelf, HighShelf — all take audio_in and output audio_out. Parameters (cutoff, Q, gain) can be set per-node or bound to graph variables.

Effect Nodes

Routing Nodes

IfNode and SwitchNode route AudioRoute values based on conditions or a selector variable. Use these for conditional audio paths — different sounds based on surface type, weather, or character state.

Output Node

Aud_OutputNode wires the final signal to a named mixing bus. Every graph needs exactly one Output node.

Using Variables

Declare variables in the Variable Panel. Bind them to filter parameter slots (right-click > Convert to Reference) or use If/Switch nodes to route based on them.

At runtime, setting a variable re-evaluates only the nodes that depend on it — the rest of the graph is untouched.

Common patterns:

Variables are set from gameplay code via the Audio Manager:

SetAudioGraphVariable(instanceId, "underwater", 0.8)
SetAudioGraphVariableBool(instanceId, "isSprinting", true)

Playing at Runtime

All Audio Event Graph playback goes through the Audio Manager.

Fire-and-Forget

For one-shot sounds with no runtime modification needed:

PlayAudioGraph("Assets/Audio/Explosion.audiograph")

Manual Control

For sounds that loop, need variable updates, or need explicit stopping:

1. AcquireAudioGraph(assetPath) — get an instance ID
2. SetAudioGraphLooping(id, true) — if it loops
3. SetAudioGraphEntity(id, entityId) — for 3D tracking
4. FireAudioGraph(id) — start playback
5. SetAudioGraphVariable(id, name, value) — update variables any time
6. StopAudioGraph(id) or FinishAudioGraph(id) — stop cleanly
7. ReleaseAudioGraph(id) — return the instance to the pool

Quick Reference

Glossary

For full definitions, see the Glossary.

See Also

• Framework API: Audio Event Graph — Full node catalog and extension guide
• The Basics: Audio Manager — Runtime playback API
• The Basics: Audio Events — Simpler fire-and-forget sound playback
• The Basics: Mixing — Mixing buses that graphs route through

Get GS_Audio

GS_Audio — Explore this gem on the product page and add it to your project.