Before using Passthrough, you should update your device to the latest Meta Quest operating system. See Update your Meta Quest software to update your Meta Quest.

Configure Unreal Project

To get started with Passthrough, set up the Unreal Engine project with the following settings:

Follow the Unreal Engine setup guide to set up Unreal Engine and create a new project.

On the menu, go to Edit > Project Settings > Meta XR, and change the following settings:

Under General, set XR API to Oclulus OVRPlugin + OpenXR backend.

Under Mobile, set Passthrough Enabled to True.

Set up passthrough using Persistent Passthrough (recommended):

This type of passthrough applies on the full screen and can stay alive for the whole duration of the app. See Persistent Passthrough for more information.

Bring the Passthrough Subsystem in any Blueprint by right clicking in the Event Graph and searching for get passthrough subsystem. From the subsystem node call the Initialize Persistent Passthrough method.
You can then configure the passthrough layer from the Details tab when selecting the node.
Persistent Passthrough Initialize node

Configure the passthrough layer. The following list describes the standard settings:

The Layer Placement orders the layer related to the scene rendering. Depending on the Placement setting, passthrough will be composited on top of the application (Overlay) or beneath the application (Underlay). The use of Overlay is deprecated and will not work over PC Link, this should be set to Underlay.

The Texture Opacity Factor controls the opacity of the whole passthrough texture.

You can customize the passthrough layer further using the additional settings.
Persistent Passthrough layer details

Customize passthrough

Customize passthrough through styling (texture opacity and edge rendering), color mapping techniques (color map type and look up tables (LUTs)), or using compositing and masking (occlusions and passthrough windows).

Wait until Passthough is ready

Passthrough is asynchronous by nature. Even though you can create a Passthrough layer instantly, its content may not be ready for rendering for several frames. This leads to a brief black frame gap. You can avoid this by using the LayerResumed event, which is emitted once the layer is fully initialized and populated with the Passthrough content.

Example usage: Layer Resumed event from component

The event is also available with Persistent Passthrough: Layer Resumed event from Persistent Passthrough

Enable based on system recommendation

You can show a VR or Passthrough background in your app based on user choice. Meta Quest devices already provide users with this choice in the home environment, and your app can leverage the user’s home environment preference. We recommend that apps default to MR or VR based on user preferences. This recommendation is available using UOculusXRFunctionLibrary::IsPassthroughRecommended() either through C++ or Blueprints.