Waveform Editor Quick Start

The Waveform Editor is an Unreal Engine plugin that lets you view, preview, and edit Sound Wave assets directly inside the editor. You can also export .wav files for use outside of the editor without losing transformation metadata.

Enable Waveform Editor

To enable Waveform Editor, follow these steps:

• In the Unreal Editor’s main menu, select Edit > Plugins.

• In the Plugins window, search for Waveform Editor and check the checkbox next to it.

  

• Restart the editor when prompted.

To open Waveform Editor, you must have a Sound Wave asset in your project. In the Content Browser, double click on the asset and the Waveform Editor will open.

You can learn more about importing Sound Waves in Importing Audio Files.

Waveform Editor UI

  With the Waveform Editor open, take a moment to get familiar with the user interface.

You can change colors, line thickness, and other display settings for the Waveform Editor in Edit > Editor Preferences > Waveform Editor Display.

Transformations

Transformations are effects that you can stack on a Sound Wave. Sound Waves can have up to one instance of each of the following transformations, in this order:

1. Trim Fade

2. Markers and Loop Regions

3. Normalize

4. Fade

You can choose which transformations are added automatically the first time you open a Sound Wave by selecting them in Launch Transformations. To open this menu, follow these steps:

1. In the Waveform Editor, select Edit > Editor Preferences.

2. Under Plugins, select Waveform Editor Transformations. 

3. Under Launch Options, click the Add (+) button to add transformations.

   

Trim Fade

Trim Fade combines two audio editing operations into one:

• Trim cuts the Sound Wave down to a specific range by setting a start time and end time.

• Fade applies a fade-in at the beginning and/or a fade-out at the end of that trimmed audio.

  

To apply Trim Fade transformation, follow these steps:

1. In the Details panel or the Processing panel, under Transformations, click the Add (+) button.

   

2. Select Waveform Transformation Trim Fade from the dropdown menu.

   

In either panel, Trim Fade appears as one transformation with both a Trim group and a Fade group of properties that you can expand and adjust.

For more information on editing fades and an explanation of curve control options, see Fade.

Marker and Loop Regions

Markers are timestamped points placed at specific positions within a Sound Wave. For example, you can use markers to indicate where a gunshot sound should sync with something in-game. Markers don't have duration; they're a labeled point in time that other systems (like Blueprint or Metasounds) can reference to trigger events at that exact moment during playback.

A loop region is a segment within a Sound Wave with a start time and end time that indicates a section of the audio meant to repeat during playback. This is useful for audio like ambient background noise or a sustained engine hum, where you want the sound to play indefinitely without an audible seam.

Adding, Editing, and Removing Markers and Loop Regions

You can add, edit, or remove markers and loop regions in a four places:

• In the Processing panel, under the Transformations dropdown.

• In the Details panel, under the Transformations dropdown.

• In the Waveform Editor toolbar, using the create and delete marker/loop buttons.

  

• In the Timeline.

Converting Between Markers and Loop Regions

Markers are functionally the same object as loop regions. This means a marker can be converted into a loop region, and vice versa, rather than needing to be recreated from scratch.

To convert a loop region into a marker (and vice versa), follow theses steps:

1. In the Timeline, right-click the loop region and select Toggle Between Marker - Loop Region.

2. To toggle it back, right-click the marker’s grab handle and select Toggle Between Marker - Loop Region again.

Interaction with Trim Fade

Markers and loop regions can be trimmed by a Trim Fade transformation. Playback is limited to within the trim range, meaning markers and loop regions outside of it will not play. However, these markers and loop regions aren't deleted; they remain inactive and are still loaded and saved during import and export.

Cue Point Origin

In a Sound Wave asset, there are two sources of marker data — from the original .wav file's data, and from the Waveform Editor's Marker Transformation.

Markers and loop regions are stored as a separate transformation layered on top of the original Sound Wave, rather than overwriting the Sound Wave's original data. This means that if the original .wav file already had marker data embedded in it, that data isn't destroyed by anything you add in the editor.

You can switch between which one is active using the Cue Point Origin dropdown in the Sound Wave's Details panel. If no marker data is present in the original .wav file, Cue Point Origin defaults to Marker Transformation and Wave File if there is data. If it's set to Wave File and you add a marker in the Waveform Editor, you'll be prompted to change Cue Point Origin to Marker Transformation.

Marker and Loop Region Properties

Markers and loop regions are defined by the FSoundWaveCuePoint struct. The following properties are readable by Blueprint:

Normalize

Normalize applies a constant amount of gain to target a maximum volume level.

To apply a Normalize transformation, follow these steps:

1. In the Details panel or the Processing panel, under Transformations, click the Add (+) button.

2. Select Waveform Transformation Normalize.

   

Under Normalization you’ll find three options to control the transformation:

Fade

Fade gradually raises or lowers volume at points you choose within the Sound Wave. Each fade region includes a fade-in and a fade-out, and can be placed anywhere on the waveform, with or without a Trim Fade transformation.

  You can apply a Fade transformation in three places:

• From the Processing panel

  

• From the Details panel

• From the Waveform Editor Toolbar

  

  Curve shapes control the rate at which volume changes over the course of a fade:

You can adjust curve shapes in four places:

• From the Waveform Editor's toolbar.

  

• From the Processing panel

  

• From the Details panel

• By right-clicking the triangle handles of a fade in or fade out in the Timeline.

  

You can adjust the duration and shape of curves in the Details or Processing panels, or by dragging the curve handles in the Timeline. The triangle handles adjust duration, and the square handles adjust the fade's start and end time.

Export and Reimport

Export and Reimport let you share edited audio with other tools or teammates, or bring in marker and loop data that was created outside the editor, without redoing your edits from scratch.

To export audio files, follow these steps:

1. In the Waveform Editor’s toolbar, click the three-dot button to choose Mono or Stereo.

   

2. Click the export button.

   

You can import files from the Waveform Editor's toolbar in three different ways:

To locate the reimport options, navigate to the editor toolbar and click the three-dot menu next to the reimport button.

Audio Analysis

Waveform Editor gives you access to audio analysis tools for calculating LUFS and SamplePeakDB. LUFS measures perceived loudness, and SamplePeakDB measures the highest sample amplitude in the audio. These are USoundWave members that display as metadata when hovering over a USoundWave asset in the Content Browser.

These values update automatically whenever you apply a transformation, so you can confirm your edits (such as a Normalize or Fade) have the loudness or peak level you expect without needing to check in an external tool.

Audio analysis is triggered in three cases:

• On asset import or reimport (per asset)

• When opening an asset in the Waveform Editor (per asset)

• Using the ResaveSoundWaveLoudness commandlet (bulk analysis)

Commandlets

FixSoundWaveTimecodeInfoCommandlet

This commandlet fixes LogSlate warnings from USoundWave::TimecodeInfo caused by incorrect symbols.

To use the commandlet, run the following command from your OS command line:

UnrealEditor-Cmd.exe "Path\To\YourProject.uproject" -run=FixSoundWaveTimecodeInfoCommandlet

To confirm the commandlet was successful, check the log output for the category LogFixSoundWaveTimecodeInfoCommandlet — that's where this commandlet writes its output. When the commandlet starts, you'll see this line first:

Fixing soundwave timecodeInfo. Note: Params are ignored.

After that, the log will list every Sound Wave the commandlet fixed. If a particular Sound Wave couldn't be saved after being fixed, an error will be logged for that asset so you know it needs attention.

ResaveSoundWaveLoudness

This commandlet analyzes legacy USoundWaves and updates their metadata to include LUFS and SamplePeakDB.

To use the commandlet, run the following command from your OS command line:

UnrealEditor-Cmd.exe "Path\To\YourProject.uproject" -run=ResaveSoundWaveLoudness

If your project uses source control (like Perforce), this commandlet needs to check out any Sound Wave files it modifies before it can save changes to them. Add the -AutoCheckOut flag to the command above to have it do this automatically, for example:

UnrealEditor-Cmd.exe "Path\To\YourProject.uproject" -run=ResaveSoundWaveLoudness -AutoCheckOut

Without this flag, the commandlet may fail to save changes to files that are still checked in.

Keyboard Shortcuts

You can customize the following default shortcuts under Edit > Editor Preferences > General > Keyboard Shortcuts > Waveform Editor.