Wwise Unreal Integration Documentation
Using the Level Sequencer

The Unreal Engine's Sequence Editor is a cinematic editing tool. You can use it to add Tracks that modify certain Actor properties in a level.

Refer to the following topics for background information on the Sequencer:

  • For instructions on how to create a Level Sequence, refer to Sequencer Overview.
  • For instructions on how to add Tracks to a Level Sequence, refer to the Adding Tracks section on the Tracks page.

Setting up Your Wwise Project

To ensure that Event lengths are properly represented in the AkAudioEvent Tracks, you must configure the Wwise project to estimate the duration of its audio Events and generate JSON metadata.

To set up your Wwise project:

  1. Open the project in Wwise Authoring.
  2. From the menu bar, click Project > Project Settings. The Project Settings dialog opens.
  3. On the SoundBanks tab, enable the following options:
    • Estimated Duration
    • Generate JSON Metadata
Required Project Settings for AkAudioEvent Tracks

Using Wwise Level Sequencer Tracks

The Wwise Integration adds two Tracks to the Sequencer:

  • AkAudioRTPC, which sets Game Parameter values.
  • AkAudioEvent, which posts Wwise Events.

You can add both of these Tracks as Master Tracks or associate them with Actors. When associated with Actors, they perform Wwise-related functions on the UAkComponent attached to the Actor. When created as Master Tracks, the AkAudioRTPC Track sets global RTPC values, and the AkAudioEvent Track posts Events on a dummy game object.

For AkAudioRTPC Tracks, you can modify Game Parameter curves with the built-in curve editor. To add key frames, place the cursor in the desired location and click Add New Key on the right side of the listed Track.

An AkAudioRTPC track in the Curve Editor view

For AkAudioEvent Tracks, you can add AkAudioEvent sections. To do so, place the cursor at the desired location and click AkAudioEvent on the right side of the listed Track. Alternatively, you can drag AkAudioEvent assets from the Content Browser directly onto an AkAudioEvent Track.

Adding an AkAudioEvent section to an AkAudioEvent Track

Displaying Waveforms for Wwise Events

The Unreal integration uses the Wwise Authoring API (WAAPI) to extend the Sequencer functionality. For more information about WAAPI and its use in the Unreal integration, refer to Wwise Authoring API (WAAPI). When Unreal is connected to the Wwise Authoring tool through WAAPI, AkAudioEvent sections can display waveforms for Wwise events. When Wwise Authoring is not open, or the Unreal integration is not connected to WAAPI, the AkAudioEvent sections only display the Event name.

Viewing AkAudioEvent Section Waveforms

AkAudioEvent sections display audio waveforms for Events that contain Audio Sources. The waveform in an AkAudioEvent section shows the audio data for the longest Audio Source contained in the Wwise Event. In the following example, a Wwise Event called "Play_Sound" contains three Audio Sources: "Layer_1", "Layer_2", and "Layer_3".

Example Wwise Event with three Audio Sources

If an AkAudioEvent section is added and its Event property is set to "Play_Sound", then the longest of the three Audio Sources is displayed within the section. Note that the waveform might be followed by empty space if the Wwise Event lasts longer than the longest Audio Source that it contains. In this example, because the "Play_Sound" Event has two delayed play actions (for "Layer_2" and "Layer_3"), it lasts longer than the "Layer_1" audio source that it contains. The empty space after the waveform indicates the maximum estimated duration of the Wwise event, as calculated during SoundBank generation (see Setting up Your Wwise Project).

Example AkAudioEvent Section in Sequencer

If the length of the AkAudioEvent section exceeds the maximum estimated duration of the Wwise Event, the section contains either a flat white line or repeating diagonal lines. The flat white line indicates that the Retrigger property is disabled. The repeating diagonal lines indicate that the Retrigger property is enabled. The Retrigger property determines whether Wwise events are retriggered in the Sequencer after they finish (refer to AkAudioEvent Section Properties).

Two AkAudioEvent Sections in Sequencer. Retrigger is enabled in the 'Retrigger' section and disabled in the 'No_Retrigger' section.

Fixing "Out of Sync" Waveforms

If you change an Event's work unit in the Wwise project and those changes are not reflected in the generated SoundBanks, any AkAudioEvent sections for that event are marked as "out of sync". The waveform is displayed in red, and an asterisk is appended to the name of the AkAudioEvent section. Warnings are also printed to the output log when Events are triggered from "out of sync" sections.

Example 'Out of Sync' AkAudioEvent Section

To ensure that AkAudioEvent sections remain synchronized with the Wwise project, there are options to save the project and regenerate SoundBanks directly from the Sequencer. To synchronise all of the sections in an AkAudioEvent track, open the track's context menu (right click) and click Save Wwise project and refresh all sections (see AkAudioEvent Track Context Menu Options).

Scrubbing Tracks

The Sequencer integration supports scrubbing forwards and backwards over AkAudioEvent tracks. Drag the Sequencer playhead over AkAudioEvent sections to hear scrub snippets. To change the length of these scrub snippets, right-click the AkAudioEvent section and in the context menu, click Scrub Tail Length Ms. Refer to AkAudioEvent Section Properties for more details.

AkAudioEvent Track Context Menu Options

From the AkAudioEvent track, right-click to open a context menu that includes the following Audiokinetic-specific option:

  • Save Wwise project and refresh all sections: Saves the Wwise project in Wwise Authoring and regenerates SoundBanks for all AkAudioEvent sections in the Sequencer track. The section waveforms are then updated.

AkAudioEvent Section Context Menu Options

From the AkAudioEvent section on the track, right-click to open a context menu that includes the following Audiokinetic-specific option:

  • Match section length to Wwise event length: Matches the length of the section in the Sequencer track to the duration of the Wwise Event.

AkAudioEvent Section Properties

The property list in the context menu includes the following Wwise-specific section properties:

  • Ak Audio Event: Lists the following editable properties of the AkAudioEvent for the selected section:
    • Event: Event icon. Hover over the Audiokinetic Event icon to view the path to the Event. Double-click the icon to open the Event in the editor.
    • Event: Audiokinetic Event. Open this list to create a new Audiokinetic Event, edit or copy the selected Event, or browse to another Audiokinetic Event.
    • Retrigger Event: When enabled, the Wwise event in the Section is retriggered when the Sequence plays beyond the end of the event. Disabled by default.
    • Scrub Tail Length Ms: Sets the duration in milliseconds of the scrub snippets that are played when scrubbing over the sequence. Default is 100ms.
    • Max Source Duration: Displays the duration of the longest Audio Source contained in the Wwise Event (read only).
    • Advanced:
      • Event Name: Type the exact name of the desired Event. This field is ignored if an Event is already selected in the Audiokinetic Event list.
  • Movie Scene Ak Audio Event Section:
    • Stop at Section End: Clear this box to keep the Event playing when the end of the section is reached. Enabled by default.

Known Issues and Limitations

In general, we recommend that you use very simple AkAudioEvent sections in the Level Sequencer, such as a simple Play action on a Sound SFX. Avoid more complex Wwise Events such as those that contain delayed actions, Seek actions, or which reference Random Containers, Sequence Containers, and other non-deterministic objects. If you do use such Events, divide them into simpler events for optimal use in the Level Sequencer.

Scrubbing and playing from cursor does not work as expected on Events with delayed actions or that contain infinitely looping sounds.

Play In Editor Limitations

If a level sequence is played from the Sequencer editor window while Unreal is running in Play in Editor (PIE) mode, any AkAudioEvent tracks that are associated with game objects do not trigger events. To hear AkAudioEvent tracks that are bound to game objects, you must trigger the level sequence from the Game World.

Replication Limitations

AkAudioEvent and AkAudioRTPC tracks are triggered only on the server and are not replicated to clients.

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