Refract runs Android (Meta Quest) OpenXR apps on a Windows PC and shows them in a PC VR headset. The app runs in the Android Emulator. Refract provides an Android OpenXR runtime inside the emulator, which sends frames to the PC and receives headset and controller poses back.

Status: experimental. It works for the setups documented below, but compatibility with arbitrary games is unfinished.

How it works

Android OpenXR APK (in the Android Emulator)
  -> Refract Android OpenXR runtime (com.refract.openxrruntime)
  -> Refract protocol (poses, frames, input)
  -> Refract viewer / host bridge (Windows)
  -> PC OpenXR runtime (SteamVR)
  -> headset

The eye images are shared through a Vulkan layer that is loaded into the emulator. A translator runs ARM64-only games on the x86_64 emulator image.

Repository layout

android-runtime/      Android OpenXR runtime (native)
android-runtime-apk/  Installable runtime APK and runtime broker
platform-sdk/         Meta Platform SDK stand-in (package com.oculus.horizon)
protocol/             Pose, image and input protocol and transports
viewer/               Windows viewer: receives the shared eye textures and shows them
host-bridge/          Host bridge to a PC OpenXR runtime
launcher/             Desktop launcher (Tauri + Node backend, GPL-3.0)
scripts/              Start the emulator and launch a game
tools/                GPU layer, GLES layer, translator patches, probes, analysis
prebuilts/digitalis/  Prebuilt ARM64-to-x86_64 translator (Digitalis/Berberis)
tests/                Smoke tests and loader probes
docs/                 Setup guides and design notes

Getting started

Requirements: Windows 11, an Nvidia GPU, the Android SDK with the Android Emulator and NDK, CMake and Ninja, and SteamVR.

1. Build and set up the emulator path. See docs/windows_nvidia_emulator.md.

2. Build the viewer with viewer\build.bat.

3. Start a game. docs/yeeps_setup.md walks through a full working configuration:

   .\scripts\start_emulator.ps1 -Cores 6 -Hidden
   .\scripts\ensure_tsc.ps1
   .\scripts\launch.ps1 -Run my-run -TranslatorMode two-gear
   

   Logs for each run are written to runs\<name>\.

Architecture, status and build details are in docs/overview.md.

Note: several scripts still hardcode the author's Android SDK path (C:\Users\mixid\Android\Sdk). Change it to match your machine.

Not included

This repository contains no game APKs, Meta SDKs or Horizon OS files. You need to provide your own:

• The APKs of games you own.
• The OpenXR loader AAR, under third_party/.

The ARM64 translator is included prebuilt in prebuilts/digitalis/ (Digitalis/Berberis, Apache-2.0, with Refract's performance patch), so you don't have to build AOSP. scripts\translator.ps1 -Use digitalis installs it into the emulator.

To pass the entitlement check with the Meta Platform SDK stand-in, list the games you own in scripts/owned_games.txt. scripts/owned_games.example.txt shows the format.

Refract is meant for testing apps you own and open samples. Do not use it to bypass DRM, anti-cheat, platform security, store restrictions or application license terms.

Credits and license

Refract is based on AXRB by Florian Reintgen, and much of its code comes from AXRB. See CREDITS.md.

Refract is released under the MIT License, which keeps AXRB's MIT copyright notice. The launcher (launcher/) is GPL-3.0-or-later because it includes code adapted from RiftLift.