AkAcousticTexture

Unreal object representing a Wwise Acoustic Texture. Can be created either by drag-and-drop from the Wwise Picker or by right-clicking in the Unreal Content Browser. Once created, it can be applied on a AkSurfaceReflectorSetComponent's polygons or on a AkSpotReflector.

• Properties
  • Edit Color: Editor-only property defining the color to be used when colorizing AkSurfaceReflectorSetComponent polygons that have an AkAcousticTexture assigned.

AkSpotReflector

The Spot Reflector actor allows one to place an omnidirectional point reflector in the 3D world. Spot reflectors make sense when they are placed on far away objects that have a large radius; like a distant mountain.

Spot Reflectors will reflect any sound coming from an AkComponent that has Enable Spot Reflectors enabled and that is positioned in the same area. An AkComponent will feed to spot reflectors if they both are outside rooms. If the AkComponent is in a room, it will only feed to spot reflectors inside the same room. Rooms can be created with a volume that has an AkRoomComponent attached.

Calls AK::SpatialAudio::AddImageSource() from the Spatial Audio API on BeginPlay.

• Properties:
  • Aux Bus: AkAuxBus that has the AkReflect plug-in for early reflection DSP. This aux bus should enable game-defined auxiliary sends, with Listener Relative Routing enabled but 3D Spatialization set to None.
  • Acoustic Texture: AkAcousticTexture used to filter sounds reflected by this image source.
  • Distance Scaling Factor: Image source distance scaling. This number effectively scales the sourcePosition vector with respect to the listener and, consequently, scales distance and preserves orientation.
  • Level: Game-controlled linear level for this source.

AkSurfaceReflectorSetComponent

Representation of a Geometry Set in Unreal Engine 4. This component needs to be attached on a AVolume actor. On BeginPlay, all of the volume's enabled polygons will be sent to the SpatialAudio engine.

• Properties
  • Enable Surface Reflector Set: Enables or disables this component
  • Acoustic Surfaces: Array defining the AkAcousticTexture associated with each polygon. The index in the array is represented in the Game Viewport when the parent volume is selected. Once a texture is assigned to a polygon, the polygon is colorized using the texture's Edit Color, and the Acoustic Texture's name is printed on the polygon in the Game Viewport. Assigning None as an Acoustic Texture will make the surface completely reflectible, no additional texture filter will be applied. Each polygon can also be enabled or disabled with the Enable Surface check box.
  • Acoustic Surface Properties
    • Enable Diffraction: Enable or disable geometric diffraction for this Geometry.
    • Enable Diffraction on Boundary Edges: Enable or disable geometric diffraction on boundary edges for this Geometry. Boundary edges are edges that are connected to only one triangle. Depending on the specific shape of the geometry, boundary edges may or may not be useful and it is beneficial to reduce the total number of diffraction edges to process.
    • Associated Room: (Optional) Associate this Surface Reflector Set with a Room. Associating a surface reflector set with a particular room will limit the scope in which the geometry is visible/accessible. Leave it as None and this geometry will have a global scope. It is recommended to associate geometry with a room when the geometry is (1) fully contained within the room (not visible to other rooms except by portals), and (2) the room does not share geometry with other rooms. Doing so reduces the search space for ray casting performed by reflection and diffraction calculations. Take note that once one or more geometry sets are associated with a room, that room will no longer be able to access geometry that is in the global scope.

AkRoomComponent

This component can be added to any volume, and then create a Spatial Audio Room. Rooms have two purposes:

• Allow for oriented reverb. All Auxiliary Busses applied on a game object within a Room will be oriented towards the volume's front vector.
• Used in conjunction with AkAcousticPortal, allow for routing the wet signal from one Room through a Portal, to another Room.

In both cases, the Auxiliary Bus used should have its positioning options set to enable Listener Relative Routing for Positioning to specify a 3D Spatialization and assign an attenuation.

• Properties
  • Enable Room: Enables or disables this component
  • Priority: The precedence in which the rooms will be applied. In the case of overlapping rooms, the one with the highest priority is chosen. If two or more overlapping rooms have the same priority, the chosen room is unpredictable.
  • Wall Occlusion: Used to set the Wwise occlusion value on emitters in the Room, when no audio paths to the listener are found via sound propagation in Wwise Spatial Audio. This value can be thought of as 'thickness', because it relates to how much sound energy is transmitted through the wall. The valid range is 0.0f-1.0f, and is mapped to the occlusion curve as defined in the Wwise project.

AkSpatialAudioVolume

For your convenience, an AkSpatialAudio volume is included in the integration. It consists of a simple volume with a AkSurfaceReflectorSetComponent, a AkRoomComponent and a Ak Late Reverb Component attached.

AkAcousticPortal

Representation of a Portal in Unreal Engine 4. Allows for sounds contained in a volume with AkRoomComponent attached to leak into other volumes with AkRoomComponent attached. Such volumes overlapping with Portals are detected at initialization time. Both panned and 3D-spatialized sounds can be routed through a portal.

• Properties
  • Initial state: Whether this Portal should be initialized in an open (enabled) or closed (disabled) state.
  • Obstruction Refresh Interval: Time interval between occlusion/obstruction checks. Set to 0 to disable occlusion on this component.
  • Obstruction Collision Channel: The object collision channel used for creating the collision of the obstruction ray-casts (between the Portal and the listener) with the desired geometry.