Spatial Audio Objects
WAAPI Widgets
Classes used for the Event-Based packaging

AkAudioEvent

Unreal object representing a Wwise Event. When using Asset synchronization, assets are automatically created in the Sound Data folder. When not using automatic asset synchoronization, AkAudioEvents 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. When using Asset synchronization, assets are automatically created in the Sound Data folder. When not using automatic asset synchoronization, AkAuxBusses 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 one 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. When using Event-Based workflow, it will act as a group of events, without media. When not using Event-Based workflow, it is the only way to create SoundBanks.

• Properties
  • Auto Load: When enabled, automatically loads and unloads the SoundBank along with the Event or Auxiliary Bus referencing it. Note: This flag is only used when not using Event-Based workflow.
• 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.
  • 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 AkLateReverbComponent.

AkLateReverbComponent

This component can be added to any UPrimitiveComponent, in order to create a reverb zone from that Primitive Component. 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.
  • 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.
  • Auto Assign Aux Bus: When enabled, the aux bus for this reverb component will be assigned automatically. This is done by estimating the decay time of the reverb produced by the parent Primitive Component, given its volume and surface area. This decay value is used to select an aux bus from the Aux Bus Assignment Map in the integration settings. Enabled by default.
  • Aux Bus: AkAuxBus assigned to this volume. In the Wwise project, this aux bus should enable game-defined auxiliary sends. If you are using Late Reverb with AkRoomComponent and AkPortalComponent, it also needs to enable Listener Relative Routing for Positioning and must have a 3D Spatialization assigned.
  • Environment Decay Estimate: An estimation of the T60 (the time taken for the sound pressure level to reduce by 60dB) for the reverb's environment, based on the Primitive Component to which the late reverb is attached. This T60 value can be used to automatically assign an aux bus using the Aux Bus Assignment Map in the integration settings, and/or to drive the Decay Estimate RTPC, from the Global Reverb RTPCs in the integration settings.
  • HFDamping: An estimation of the high-frequency damping produced by the environment, based on an associated AkGeometryComponent (or AkSurfaceReflectorSetComponent if the owning Actor is a Volume). In order to estimate the HF damping, a geometry component must be associated to this reverb component using the AssociateAkTextureSetComponent function. If this late reverb component has a sibling geometry component (or surface reflector set component), they will be associated automatically and there is no need to call AssociateAkTextureSetComponent. If AssociateAkTextureSetComponent is used, the HFDamping value will only be accurate during play. A value of 0.0 indicates uniform damping across all frequencies. A value > 0.0 indicates more damping for higher frequencies than lower frequencies. A value < 0.0 indicates more damping for lower frequencies than high frequencies. This value can be used to drive the HFDamping RTPC, from the Global Reverb RTPCs in the integration settings.
  • Time to First Reflection: An estimation of the time taken for the first reflection to reach the listener, based on the primitive component to which the late reverb is attached. This is estimated based on an emitter and listener being positioned at the centre of the parent primitive component. This value can be used to drive the Time To First Reflection RTPC, from the Global Reverb RTPCs in the integration settings.
• Blueprint Functions
  • Associate Ak Texture Set Component: Set the component (either AkGeometryComponent or AkSurfaceReflectorSetComponent) that will be used to estimate the HFDamping. For example, in a Blueprint that has a static mesh component with an AkGeometryComponent child component, this function can be called in BeginPlay to associate that AkGeometryComponent with this reverb component. If this late reverb component has a sibling AkGeometryComponent (or AkSurfaceReflectorSetComponent), they will be associated automatically and there is no need to call this function.

Note: An Ak Late Reverb Component must be attached to a UPrimitiveComponent in the component hierarchy. If an Ak Late Reverb Component does not have a UPrimitiveComponent as its parent, an error will be logged and the component will have no effect.

Note: When using an AkLateReverbComponent in a custom Blueprint class, it is recommended to use a simple collision component as the parent. For example, you could use a BoxCollision, SphereCollision, or CapsuleCollision component. Refer to Spatial Audio Blueprint Components for more information.

Note: In order to use the Environment Decay Estimate, HFDamping, and Time to First Reflection values with the Global Reverb RTPCs in the integration settings, the reverb component must have a sibling AkRoomComponent (in other words, an AkRoomComponent that shares the same Primitive parent component). The RTPC values will be set on the Room IDs.

Note: When working with Ak Late Reverb Components in the level editor, it is strongly recommended to enable Realtime in the Viewport Options. If Realtime is disabled, the reverb parameter estimation values will not be updated when actors are scaled or when acoustic texture parameters are changed in the Wwise project.

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.
  • Use Reverb Volumes: Sets whether or not the component is influenced by AAkReverbVolumes.
  • Occlusion
    • 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.
  • Spatial Audio
    • Enable Spot Reflectors: Enable reflections on AkSpotReflector for this AkComponent.
    • Radial Emitter
      • Outer Radius: Set the field to the desired outer radius size. The number set is directly sent to the spatial audio AK:SpatialAudio::SetGameObjectRadius() call without any transform. When the actor is selected, a yellow sphere outline is drawn around the game object's position to visualize the size entered.
      • Inner Radius: Set the field to the desired inner radius size. The size cannot be higher than the outer radius size. The number set is directly sent to the spatial audio AK:SpatialAudio::SetGameObjectRadius() call without any transform. When the actor is selected, a yellow sphere outline is drawn around the game object's position to visualize the size entered.
    • Reflect
      • Early Reflection Aux Bus: Set the early reflections auxiliary bus for the current game object. The component will call AK::SpatialAudio::SetEarlyReflectionsAuxSend() with the selected auxiliary bus. The auxiliary bus parameter applies to sounds playing on the game object that have not specified an early reflections auxiliary bus in the authoring tool. The early reflection auxiliary bus parameter specified on individual sounds takes priority over the value passed here.
      • Early Reflection Aux Bus Name: Set the early reflections auxiliary bus for the current game object. The component will call AK::SpatialAudio::SetEarlyReflectionsAuxSend() with the selected auxiliary bus. The auxiliary bus parameter applies to sounds playing on the game object that have not specified an early reflections auxiliary bus in the authoring tool. The early reflection auxiliary bus parameter specified on individual sounds takes priority over the value passed here.
      • Early Reflection Bus Send Gain: Set an early reflections send volume for the current game object. It will be used to control the volume of the early reflections send. The component will call AK:SpatialAudio::SetEarlyReflectionsVolume() with the entered volume value. The value is combined with the early reflections volume specified in the authoring tool, and is applied to all sounds playing on the game object. Valid values are [0, 1]. Setting the volume to 0 will disable all reflection processing for this game object.
    • Reflect (DEPRECATED)
      • Early Reflection Order: (DEPRECATED) As of 2019.2, the Early Reflection Order needs to be set in the Spatial Audio Initializaion Settings in Project Settings.
      • Early Reflection Max Path Length: (DEPRECATED) As of 2019.2, the Early Reflection Max Path Length is set by the sound's Attenuation Max distance value in the Authoring.
    • Room (DEPRECATED)
      • Room Reverb Aux Bus Gain: (DEPRECATED) As of 2019.2, the Room Reverb Aux Bus Gain is set by the Game-Defined Auxiliary Sends Volume in the Sound Property Editor in the Authoring.
    • Geometric Diffraction (DEPRECATED)
      • Diffraction Order: (DEPRECATED) As of 2019.2, Diffraction needs to be enabled in the Sound Property Editor in the Authoring.
      • Diffraction Max Paths: (DEPRECATED) As of 2019.2, Diffraction needs to be enabled in the Sound Property Editor in the Authoring.
      • Diffraction Max Path Length: (DEPRECATED) As of 2019.2, Diffraction needs to be enabled in the Sound Property Editor in the Authoring.
    • 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.
  • AkEvent
    • 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.

  See also

  • features_blueprintcomponent
  • Creating AkComponent from C++.

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.