What is the Unreal LIV SDK? - LCK Documentation

The LIV SDK for Unreal Engine is a Mixed Reality (MR) toolset that enables VR developers to blend real-world video with virtual environments. It offers a complete solution for MR capture workflows with adjustable performance settings and integrates with Meta’s Presence Platform for advanced features in Unreal Engine 5.4+ through the Meta Fork.

Key Features

Mixed Reality Capture

Creates seamless real-time MR capture by blending the player’s real-world video with virtual VR environments.
Supports two capture workflows:
- Background-only Capture: Isolates the background layer for compositing.
- Full Composition: Combines real and virtual elements into a unified view.

Customizable Capture Methods

Choose from three capture methods that balance performance, transparency

Capture Method	Performance	Transparency	Post-Processing	Use Case
LivCaptureSingle	Fastest	❌	✅	Best for performance-critical scenarios where transparency and layering are not required.
LivCaptureGlobalClipPlaneNoPostProcess	Moderate	✅	❌	Use for transparent materials when post-processing effects (ex: bloom) are not needed.
LivCaptureGlobalClipPlanePostProcess	Slower	✅	✅	Use when full transparency and post-processing effects (ex: reflections, bloom) are required.
LivCaptureBackgroundTransparency (WIP don’t use)	Moderate	✅ (Background)	❌	Captures only the background layer with transparency. The player remains excluded.
LivCaptureMulti (WIP don’t use)	Moderate	✅	✅	Use for multi-layer captures where both transparency and post-processing are needed.

Meta Presence Platform Integration (Unreal Engine 5.4+)

When using Unreal Engine 5.4 or later, the LIV SDK connects with Meta’s Presence Platform via the Meta Fork to deliver these advanced Mixed Reality features:

Passthrough: Seamlessly blend the real environment with virtual content in real-time.
Spatial Anchors: Lock virtual objects to specific points in the real world.
Scene API: Harness real-world spatial data to create dynamic MR experiences.

Note: Meta Presence Platform features are only available when using the Meta Fork of Unreal Engine, or the Stock Engine + MetaXR plugin.

Device and Platform Compatibility

Supported Unreal Engine Versions

Version	Supported Features
4.26 to 5.4	MR capture for Green Screen and immersive workflows.
5.4+ (Meta Fork & Stock Engine + MetaXR plugin)	Supports Meta Presence Platform (Passthrough, Anchors).

Platform Requirements

DirectX 11: Required for all LIV functionality.
- Note: DirectX 12 is not supported. Use DirectX 11 via Unreal’s Project Settings.
Windows OS: Supported for development and deployment.

Hardware Requirements

VR Headsets: SteamVR-compatible devices for camera tracking (Oculus Quest, HTC Vive, Valve Index, etc)

What’s Included in the LIV SDK?

The LIV SDK includes these essential components for Unreal Engine integration:

Core Plugin Files:
- LIV.uplugin: Unreal Engine plugin definition file.
- Source Folder: C++ source code for MR functionality.
- Content Folder: Essential assets (ex: shaders, configuration files).
Configuration Tools:
- Settings for capture methods, and clipping planes. (Ignore “Transparency” option)
- Compatibility settings for Meta Presence Platform features.

​Key Features

​Mixed Reality Capture

​Customizable Capture Methods

​Meta Presence Platform Integration (Unreal Engine 5.4+)

​Device and Platform Compatibility

​What’s Included in the LIV SDK?