Spatial Audio Objects
WAAPI Widgets

AkAudioEvent

Unreal object representing a Wwise Event. Can be created either by drag-and-drop from the Wwise Picker or by right-clicking in the Unreal Content Browser. Its name should exactly match the name of an Event in the Wwise Project.

• Properties
  • Required Bank: Specifies the SoundBank that contains this Event along with its structures and media.
• Unreal Content Browser Context Menu Options
  • Play Event: Posts the Event.
  • Stop Event: Stops all currently playing Events.

AkAuxBus

Unreal object representing a Wwise Auxiliary Bus. Can be created either by drag-and-drop from the Wwise Picker, or by right-clicking in the Unreal Content Browser. Its name should exactly match the name of an Auxiliary Bus in the Wwise Project. This allows to add plug-in media to a SoundBank from within the Unreal Editor.

• Properties
  • Required Bank: Specifies the SoundBank that contains this Auxiliary Bus along with its associated plug-in media.

AkAudioBank

Unreal object representing a Wwise SoundBank. Can be created by right-clicking in the Unreal Content Browser.

• Properties
  • Auto Load: When enabled, automatically loads and unloads the SoundBank along with the package referencing it. Note: Enabling this flag does not instantly load the bank in the editor; it is only applied on the next package load.
• Unreal Content Browser Context Menu Options
  • Generate Selected SoundBank(s)...: Launches a dialog window where a SoundBank Generation operation can be performed on a list of SoundBanks.
  • Load Bank: Loads this SoundBank.
  • Unload Bank: Unloads this SoundBank.
  • Clear Banks: Unloads all currently loaded SoundBanks, including the Init bank.
  • Load Init Bank: Loads the Init Bank. This Bank must be loaded prior to any other SoundBank.
  • Refresh All Banks: Stops all sounds; unloads and then loads all currently loaded SoundBanks.

AkAmbientSound

AkAmbientSound is an AActor class used in the same way as the AAmbientSound object that is supplied with the default Unreal Audio system. Its playback is controlled either via its own object Blueprint functions, or by using the global helper functions Start All Ambient Sounds and Stop All Ambient Sounds. An AkAmbientSound also contains an AkComponent, which has its own properties.

• Properties
  • Stop When Owner Is Destroyed: When enabled, the Event is stopped automatically when the AkAmbientSound is destroyed.
  • Auto Post: Automatically post the associated AkAudioEvent on BeginPlay.
• Blueprint Functions
  • Start All Ambient Sound: Starts the playback of all ambient sounds.
  • Start Ambient Sound: Starts the playback of the selected ambient sound.
  • Stop All Ambient Sound: Stops the playback of all ambient sounds.
  • Stop Ambient Sound: Stops the playback of the selected ambient sound.

AkReverbVolume

AkReverbVolume is an AVolume class used in a similar way to the AReverbVolume object that is supplied with the default Unreal Audio system. It can be spawned from any Brush in the Editor. The reverb effect is obtained via an Ak Late Reverb Component.

Ak Late Reverb Component

This component can be added to any volume, allowing to create a reverb zone from it. The reverb effect is obtained by assigning a Wwise Auxiliary Bus to the component, and routing all AkComponents entering this volume to the associated Wwise Auxiliary Bus. If there is volume overlap, a Priority property is used to determine which Auxiliary Buses the target AkComponent is routed to. A temporal fade in/out Effect is applied to the level of the Auxiliary Bus when entering/exiting a AkReverbVolume. Note that if an Ak Late Reverb Component is active on an actor that also has an AkRoomComponent, the Late Reverb Component will be disabled and reverb will be handled by the AkRoomComponent using the Spatial Audio engine to render Effects.

• Properties
  • Enable Late Reverb: Enables or disables this component.
  • Aux Bus: AkAuxBus assigned to this volume. This aux bus should enable game-defined auxiliary sends. If you are using Late Reverb with AkRoomComponent and AkAcousticPortal, it also needs to enable Listener Relative Routing for Positioning and set a 3D Spatialization.
  • Send Level: Maximum Send Level associated with the Wwise Auxiliary Bus.
  • Fade Rate: Rate at which to fade in/out the SendLevel of the current Late Reverb Component when entering/exiting it, in percentage per second (0.2 will make the fade time 5 seconds).
  • Priority: The precedence in which the Late Reverb Components will be applied. In the case of overlapping volumes, only the ones with the highest priority are chosen (the number of simultaneous Late Reverb Components is configurable in the Unreal Editor Project Settings under Plugins > Wwise). If two or more overlapping Late Reverb Components have the same priority, the chosen Late Reverb Components is unpredictable.

AkComponent

AkComponent is derived from USceneComponent and represents an active Wwise event.

• Properties
  • Attenuation Scaling Factor: If the Ambient Sound uses attenuation in Wwise, this property allows modifying the attenuation computations on this ambient sound to simulate sounds with a larger or smaller area of effect.
  • Occlusion Refresh Interval: Set the time interval between occlusion/obstruction checks (direct line of sight between the listener and this game object). Set to 0 to disable occlusion/obstruction on this component. We recommend disabling it if you want to use full Spatial Audio diffraction.
  • Ak Audio Event: The AkAudioEvent that is posted when the AkAmbientSound object is instructed to start playing. If you want to use Spatial Audio features, the sound effect of the Event should enable game-defined auxiliary sends.
  • Spatial Audio Properties:
    • Reflect:
      • Early Reflection Aux Bus: AkAuxBus with the AkReflect plug-in. Set to None to disable geometric reflections. This aux bus should enable game-defined auxiliary sends, with Listener Relative Routing enabled but 3D Spatialization set to None.
      • Early Reflection Aux Bus Name: If no AkAuxBus is entered in Early Reflection Aux Bus, Early Reflection Aux Bus Name will be used. Set to AK_INVALID_UNIQUE_ID to disable geometric reflections.
      • Early Reflection Order: Maximum number of reflections that will be processed when computing indirect paths via the geometric reflections API. Reflection processing grows exponentially with the order of reflections, so this number should be kept low. Valid range: 1-4.
      • Early Reflection Bus Send Gain: Send gain (0.f-1.f) that is applied when sending to the bus that has the AkReflect plug-in.
      • Early Reflection Max Path Length: A heuristic to stop the computation of reflections. Should be no longer (and possibly shorter for less CPU usage) than the maximum attenuation of the sound emitter.
      • Enable Spot Reflectors: Enable reflections on AkSpotReflector.
    • Room:
      • Room Reverb Aux Bus Gain: Send gain (0.f-1.f) that is applied when sending to the bus that is associated with the room that the emitter is in.
    • Geometric Diffraction:
      • Diffraction Order: The maximum number of edges that the sound can diffract around between the emitter and the listener.
      • Diffraction Max Paths: The maximum number of paths to the listener that the sound can take around obstacles.
      • Diffraction Max Path Length: The maximum length that a diffracted sound can travel. Should be no longer (and possibly shorter for less CPU usage) than the maximum attenuation of the sound emitter.
    • Debug Draw options: This allows you to visualize the raycasts performed by the Spatial Audio Engine, as well as the triangles hit by these raycasts, allowing you to easily debug what is going on in the Spatial Audio engine. This only works on one component at a time.
• Blueprint Functions
  • Post Ak Event: Starts playback of the specified Event.
  • Post Trigger: Posts a Trigger to the Event associated with the component.
  • Set Listeners: Sets the listeners of this UAkComponent.
  • Set Occlusion Refresh Interval: Sets the time interval at which the UAkComponent performs occlusion calculations. Set to 0 to turn off occlusion on the component.
  • Set RTPC Value: Sets the value of the RTPC of the Event associated with the component.
  • Set Stop when Owner Destroyed: Sets the StopWhenOwnerDestroyed value on the component.
  • Set Switch: Sets a Switch of the Event associated with the component.
  • Stop: Stops playback of the Event associated with the component.
  • Use Reverb Volumes: Sets whether the component is influenced by AAkReverbVolumes or not.

AkAudioInputComponent

AkAudioInputComponent is derived from AkComponent and represents an audio input instance.

• Blueprint Functions
  • Post Associated Audio Input Event: Starts playback of the specified Event and registers the appropriate callbacks.