Flax Audio System Plugin

Middleware-agnostic audio system for Flax Engine.

This repository contains two modules:

• AudioSystem (runtime): request pipeline, scene actors, and gameplay scripts
• AudioSystemEditor (editor): settings UI, toolbar integration, and build deploy hook

Repository: https://github.com/SparkyStudios/FlaxAudioSystemPlugin

Features

• Middleware abstraction via AudioMiddleware (implement your own backend as a native plugin)
• Threaded request processing (AudioSystem + AudioTranslationLayer) with main-thread callbacks
• Scene actors:
  • AudioProxyActor: spatial audio entity that tracks transform
  • AudioListenerActor: spatial listener (supports default listener + override actors)
  • AudioBoxEnvironmentActor / AudioSphereEnvironmentActor: environment zones with falloff
• Gameplay scripts:
  • AudioTriggerScript: play/stop triggers, optional obstruction/occlusion raycasts
  • AudioRtpcScript: set/reset RTPC values
  • AudioSwitchStateScript: set switch states
  • AudioAnimationScript + AudioAnimEvent: trigger audio from animation events
• Editor integration:
  • “Audio System” settings with master gain + mute
  • game cooking deploy hook that forwards to middleware (DeployFiles)

Requirements

• Flax Engine >= 0.0.6167 (see AudioSystem.flaxproj)

Installation

Add this project as a reference to your Flax game project, then rebuild.

1. Clone this repository somewhere on disk (commonly next to your game project).
2. Edit your game .flaxproj and add a reference to AudioSystem.flaxproj:

{
  "References": [
    { "Name": "path/to/FlaxAudioSystemPlugin/AudioSystem.flaxproj" }
  ]
}

1. Regenerate project files and build (or open the project in Flax Editor and let it compile).

Quick Start (Runtime)

This repository provides the audio system, but does not ship with an actual middleware backend. To get sound, you need to load a backend plugin that implements AudioMiddleware and registers it with the system.

1) Bind a middleware backend

In your backend plugin (or game code), register the middleware and start the audio system:

#include <AudioSystem/Core/AudioSystem.h>
#include <AudioSystem/Core/AudioMiddleware.h>

void BindAudioMiddleware(AudioMiddleware* middleware)
{
    auto* audioSystem = AudioSystem::Get();
    audioSystem->RegisterMiddleware(middleware);
    audioSystem->Startup();
}

If your backend uses a JSON configuration asset, forward it to the system:

AudioSystem::Get()->LoadConfiguration(TEXT("Content/Audio/MiddlewareConfig.json"));

2) Add a listener

• Place an AudioListenerActor in the scene (often parented to the camera).
• Set IsDefault = true to make it the scene-wide default listener (used by obstruction/occlusion).

3) Add an emitter

• Place an AudioProxyActor where you want a spatial emitter.
• Add AudioTriggerScript on the same actor and set PlayTriggerName to a trigger registered by your middleware.
• Call Play() from code or enable PlayOnActivate.

4) Optional: environments and parameters

• Add an AudioBoxEnvironmentActor or AudioSphereEnvironmentActor and set EnvironmentName to drive environment sends for proxies inside the zone.
• Add AudioRtpcScript for runtime parameters.
• Add AudioSwitchStateScript for switch states.

C# Convenience API

For common operations from gameplay scripts, use AudioManager:

using AudioSystem;
using FlaxEngine;

AudioManager.Play(actor, "Footstep");
AudioManager.SetRtpc(actor, "Speed", 0.75f);
AudioManager.SetSwitchState(actor, "Surface_Stone");

License

Apache License 2.0 (https://www.apache.org/licenses/LICENSE-2.0).