XR Architecture & Input

XR Architecture & Input

XR (Extended Reality) is the umbrella term covering Virtual Reality (VR), Augmented Reality (AR), and Mixed Reality (MR). Unity uses a modular architecture to support diverse headset hardware.

XR Plugin Management

Instead of importing individual SDKs for each brand of headset, Unity uses XR Plugin Management:

1. Open Edit -> Project Settings -> XR Plugin Management.
2. Install the plugin manager.
3. Check the loader box for your target hardware (e.g. OpenXR for most VR headsets, Oculus for Meta Quest, or Apple visionOS).

This ensures your game code calls a unified rendering API, while the plugin handles the translations for the hardware.

OpenXR Standard

OpenXR is a royalty-free open standard created by Khronos Group. It allows developers to build cross-platform VR/AR applications that run on compatible hardware without recompiling code for each headset brand.

XR Origin (The Camera Rig)

In standard games, you place a camera. In VR, you need an XR Origin GameObject:

• Camera Offset: Positions the virtual camera to match the player's physical height.
• Main Camera: Tracks the headset position and rotation.
• Left/Right Hand Controllers: Tracks the physical motion controllers in 3D space, updating their positions and rotation offsets automatically.

TL;DR

• XR covers Virtual, Augmented, and Mixed reality environments.
• XR Plugin Management loads hardware runtimes (OpenXR, Oculus, ARKit).
• OpenXR is the standard API for cross-platform hardware compatibility.
• XR Origin acts as the coordinate rig for cameras and controllers.