Hololight Stream for Unreal Engine component - Passthrough
Passthrough
Hololight Stream supports passthrough mode for devices like Meta Quest 2, Meta Quest Pro, and Meta Quest 3 that support it.
Enable passthrough
To enable passthrough in Unreal Engine:
-
Select Edit > Project Settings,
-
Set Alpha Output to true.
To use passthrough on the Level in the VR Template, remove or hide the Sky Sphere.
| In Unreal Engine 5.4 and earlier Alpha Output is Enable alpha channel support in post processing. Set this to Allow through Tonemapper. |
Use passthrough
In order to use passthrough during runtime, use the Blueprint functions to get and set the passthrough state. Additionally, for passthrough to work properly, the level’s background should be black or transparent. This means not using a Sky Sphere.
Example
To use passthrough the server-side, refer to the VR Template’s WidgetMenu Blueprint. This sample demonstrates the two Hololight Stream functions related to passthrough:
| Blueprint | Description |
|---|---|
bool GetPassthrough() |
Returns true if the passthrough is enabled and false if not. |
bool TrySetPassthrough(bool bEnable) |
Enables or disables the passthrough according to the input "bEnable". Returns true if the operation is successful. |
Additionally in the VRPawn, there is an example of Get Passthrough for getting the client setting on connection to setup the level.