Hello everyone,
I’m currently developing a Mixed Reality project in Unreal Engine 5.7.3 targeting Meta Quest 3 via Link. I am facing a critical incompatibility between the MetaXR/MRUK plugin and the DirectX 12 rendering pipeline.
The Context: My project relies on features that require DX12. I am using a recompiled version of the MetaXR Plugin (v1.115.0) and MRUK.
The Problem:
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Oculus OVRPlugin Backend: If I use this recommended path, the scene/anchor data loads correctly, but the rendering is broken in DX12 (one eye flickers or remains white). This appears to be related to HZB/Occlusion regressions in UE 5.7.
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Epic Native OpenXR Backend: If I use this path, the rendering is perfect in both eyes, but MRUK fails to fetch real-world data. I get the following errors:
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MRUK Shared: OpenXR not initialized. Can not start anchor discovery.
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Failed to start anchor discovery: 3.
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What I’ve already tried:
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Added
com.oculus.permission.USE_ANCHOR_APIandcom.oculus.permission.USE_SCENEto Extra Permissions. -
Verified that ‘Anchor Support’ and ‘Scene Support’ are enabled in the MetaXR plugin settings.
The Question: It seems the Epic Native OpenXR instance is not correctly registering the Meta vendor extensions required for Scene/Anchors when used outside of the official Meta Engine Fork.
Has anyone successfully bypassed ‘Error 3’ while using the Epic Native backend in UE 5.7? Is there a specific configuration in DefaultEngine.ini or a C++ modification in the plugin’s GetRequiredExtensions method to force these extensions to load on a standard Epic build?
Thanks for any help!