Oculus Lipsync offers an Unreal Engine plugin for use on Windows or macOS that can be used to sync avatar lip movements to speech sounds and laughter. Oculus Lipsync analyzes the audio input stream from microphone input or an audio file and predicts a set of values called visemes, which are gestures or expressions of the lips and face that correspond to a particular speech sound. The term viseme is used when discussing lip reading and is a basic visual unit of intelligibility. In computer animation, visemes may be used to animate avatars so that they look like they are speaking.
Oculus Lipsync uses a repertoire of visemes to modify avatars based on a specified audio input stream. Each viseme targets a specified geometry morph target in an avatar to influence the amount that target will be expressed on the model. Thus, with Oculus Lipsync we can generate realistic lip movement in sync with what is being spoken or heard. This enhances the visual cues that one can use when populating an application with avatars, whether the character is controlled by the user or is a non-playable character (NPC).
The Oculus Lipsync system maps to 15 separate viseme targets: sil, PP, FF, TH, DD, kk, CH, SS, nn, RR, aa, E, ih, oh, and ou. The visemes describe the face expression produced when uttering the corresponding speech sound. For example the viseme sil corresponds to a silent/neutral expression, PP corresponds to pronouncing the first syllable in “popcorn” and FF the first syllable of “fish”. See the Viseme Reference Images for images that represent each viseme.
These 15 visemes have been selected to give the maximum range of lip movement, and are agnostic to language. For more information, see the Viseme MPEG-4 Standard.
The following animated image shows how you could use Oculus Lipsync to say “Welcome to the Oculus Lipsync demo.”
In Lipsync version 1.30.0 and newer, Lipsync offers support for laughter detection, which can help add more character and emotion to your avatars.
The following animation shows an example of laughter detection.
The Oculus Lipsync Unreal plugin is compatible with Unreal Engine 4.20 or later, targeting Android, Windows and macOS platforms. See the Unreal Engine guide for more details on the recommended versions.
To start using Oculus Lipsync in your Unreal project:
[Install-Directory]\Epic Games\UE_x.xx\Engine\Plugins. For example for Unreal version 4.20 on Windows, you could find this folder at the following location,
C:\Program Files\Epic Games\UE_4.20\Engine\Plugins.
Create a new project or open an existing project in Unreal Engine. From the Edit menu, select Plugins and then Audio. You should see the Oculus Lipsync plugin as one of the options. Select Enabled to enable the plugin for your project.
The following image shows an example.
|Using Oculus Lipsync||Using The Oculus Lipsync Package|
|Use precomputed visemes to improve performance||Guide to Precomputing Visemes for Unreal Engine|
|Lipsync Sample||Exploring Oculus Lipsync with the Unreal Sample|
|Viseme reference images||Viseme Reference|