Overview⌗

By the end of this lesson, you’ll:

  • Understand 2D vs. 3D events in FMOD and when to use each
  • Configure a Studio Listener so the player “hears” your world
  • Build a spatialized FMOD event (Fireflies) and wire it up in Unity
  • Learn two reliable ways to position events in 3D: set3DAttributes and AttachInstanceToGameObject
  • Choose the right data sources for positioning (Transform and Rigidbody)
  • Apply prefab best practices and avoid common pitfalls

Prerequisites⌗

  • Unity with the FMOD Unity Integration installed
  • An FMOD Studio project with banks building into your Unity project
  • A Unity scene with a controllable camera and at least one GameObject to emit sound

2D vs. 3D in FMOD (and why 3D isn’t only for “3D games”)⌗

  • 2D events play without spatialization—no distance attenuation or positional panning.
  • 3D events include a spatializer that:
    • Applies distance-based attenuation (volume changes with proximity)
    • Pans left/right to simulate direction relative to the listener

Use 3D events even in side-scrollers or top-down games whenever you want distance and direction cues (e.g., off-screen enemies, ambient sources).

Our goal: a spatialized Fireflies emitter that loops as you approach and fades out as you walk away.

Step 1 — Create a Spatialized Event in FMOD⌗

  1. In FMOD Studio, create folders:
    • SFX → Environment
  2. Create a 3D Timeline Event named FireFlies under SFX/Environment and assign it to the Master bank.
    1. Notice the spatializer component is added automatically.
  3. Add your looping audio asset (e.g., FireFlies_Loop_01) to the event and add a loop region.
    1. Remember: assets are in the Audio Bin (ctrl + 3).
  4. Leave the spatializer’s default curve for now; you’ll tweak min/max distance and curve later.
  5. Build banks and save.

Tip: For teaching, prepare several presets of the distance curve so students can A/B the perceptual effects quickly during lab.

Step 2 — Add a Studio Listener to Your Player Camera in Unity⌗

  • Add the Studio Listener component to the same GameObject that has your active Camera (your “ears” should live with your “eyes”).
  • Our camera component is on the Camera Brain GameObject, which is a child of CameraRig.
  • If your camera rig is a prefab (common in character controllers), add the component to the prefab so all scenes inherit it.
    • Find the prefabs in your Project window at Prefabs -> Utilities.
    • Open the prefab, find the Camera Brain GameObject, and add Studio Listener there.
    • Return to the scene by clicking the back arrow in the top-left of the Scene view.

Prefab reminder: If you add the listener to a scene instance of a prefab, either “Open Prefab” and add it there, or click “Apply” in the Inspector so it persists across scenes.

Step 3 — Script the Event Instance⌗

Create a C# MonoBehaviour (e.g., F_FireFlies.cs) script in your FMOD Scripts folder. Find the fireflies GameObject in the Hierarchy under Effects -> FireFlies and attach to the prefab to open it with the right arrow next to the word FireFlies. After that you can see that each of the other FireFlies objects also have the same script attached .

1. Create the F_FireFlies Script⌗

using System.Collections;
using System.Collections.Generic;
using UnityEngine;

public class F_FireFlies : MonoBehaviour
{
    FMOD.Studio.EventInstance FF;
    Rigidbody rb;

    // Start is called before the first frame update
    void Start()
    {
        FF = FMODUnity.RuntimeManager.CreateInstance("event:/SFX/Environment/FireFlies");
        rb = GetComponent<Rigidbody>();
        FMODUnity.RuntimeManager.AttachInstanceToGameObject(FF, transform, rb);
        FF.start();
        FF.release();
    }

    void OnDestroy()
    {
        FF.stop(FMOD.Studio.STOP_MODE.ALLOWFADEOUT);
    }
}

Note: there are performance enhancements possible here, but this is the simplest reliable pattern for most use cases.

3. (Optional) Add a Rigidbody⌗

If your FireFlies object drifts or moves dynamically:

  • Add a Rigidbody component.
  • Uncheck “Use Gravity” if you want it to float.
  • FMOD will automatically use its velocity to calculate Doppler effects.

If it’s a static ambience point, skip the Rigidbody—AttachInstanceToGameObject will still position it using the Transform.

4. Test in Play Mode⌗

  1. Enter Play Mode.
  2. Move your player camera (with the Studio Listener attached) around the FireFlies object.
  3. Listen for panning and attenuation:
    • Louder when close
    • Softer when distant
    • Panned to the left/right depending on listener orientation

If it sounds static or incorrect, double-check:

  • The event in FMOD is 3D, not 2D.
  • The event reference is assigned correctly in Unity.
  • The Studio Listener is active on the main camera.

5. Alternative: Manual Positioning with set3DAttributes⌗

If you’re managing position manually (e.g., procedural motion, teleports, or networked actors), replace the OnEnable body with:

void Update()
{
    if (rb != null)
        instance.set3DAttributes(RuntimeUtils.To3DAttributes(transform, rb));
    else
        instance.set3DAttributes(RuntimeUtils.To3DAttributes(transform));
}

Use this version if you want fine-grained control over when spatial data is updated—especially useful for non-Unity physics movement.