openxr-pose-layer

Name: openxr-pose-layer
Author: Heath Howren

Record and replay OpenXR tracking

Price

Free

Version

1.0.1

Platform

OpenXR

License

MIT

Free & Open Source OpenXR API Layer VR Record & Replay C++20

A tracking bug is hard to chase when the only way to repeat it is to move a headset the same way again. openxr-pose-layer sits between a VR app and the OpenXR runtime as an explicit API layer. In log mode it prints the tracking and input calls the app makes, with timings. In record mode it writes every frame’s head pose, eye views, controller poses and action states to a small binary file. In replay mode it feeds those poses back into the app and rewrites the poses the app submits for display. The same motion runs again with no headset moving. That gives a VR developer a repeatable repro for a tracking bug, and a CI job a fixed input to render against. It watches what a VR app asks the runtime for, the way Pointer Lab watches what a game reads and writes.

Free

Layer DLL, manifest and poseplay.exe. Run install.ps1 to register it for your user

↓ Download from GitHub View Source on GitHub

Developer

Game Reversal Club

Open Source Software

See all software from this developer

What You Get

Run poseplay info on a recording and you get this summary. This is real output, over a 120-frame recording the layer wrote in record mode. The layer was driven by its own test harness, not by a headset.

poseplay 1.0.1
file            sample.oxrr
format version  1
frames          120
duration        1322.2 ms  (90.0 fps)
view sets       120
space locates   120 single, 0 grouped
inputs          0 pose, 120 boolean, 120 float, 0 vector2f
head position   x [-0.0300, 0.0300]  y [1.5500, 1.6500]  z [-0.0200, 0.0200]  (120 frames)

Each frame is one xrWaitFrame. The harness made one xrLocateViews, one xrLocateSpace, one boolean and one float action-state call per frame, so each of those counts is 120. It never asked for a pose or vector2f action state, so those read 0.

How It Works

Records by frame, not by clock
Each frame is one xrWaitFrame. Poses and inputs are stored under the frame index the layer assigns, and replayed in the order they were recorded. Nothing is keyed on an XrSpace or XrAction handle, because those do not survive into a new run.
Intercepts the calls that carry motion
xrWaitFrame, xrLocateViews, xrLocateSpace, xrLocateSpaces, xrSyncActions, the four xrGetActionState* calls, and xrEndFrame. Anything else passes straight through.
Replays into the compositor too
In replay mode the locate and action-state calls return the recorded values. xrEndFrame rewrites the projection-layer view poses as well, so an app that caches its poses still renders from the recorded path. Frame timing stays whatever the runtime returns.
Speed, loop and offset
A time scale of 2.0 skips every other recorded frame; 0.5 shows each one twice. Replay can loop at the end or hold on the last frame. An x y z yawDegrees offset plays the recorded path from a new place or facing.
A layer, not a runtime
It does not invent tracking. Each intercepted call still goes down to the runtime, and in replay mode the recorded values replace what comes back. Running an app with no headset needs a null runtime under the layer.
poseplay
Summarize a recording, dump per-frame times and head positions, or trim it to a frame range, reindexed from zero. Add --json for scripts.

Item Specifics

Name

openxr-pose-layer

Author

Heath Howren (“Cyborg Elf”)

Version

1.0.1 (2026)

Type

Explicit OpenXR API layer, plus the poseplay recording tool

Platform

Windows, x64 build. Registered per user under HKEY_CURRENT_USER

License

MIT License

Price

Free

Language

C++20

OpenXR

Built against the OpenXR 1.1 headers (OpenXR SDK release-1.1.43). No SDK code is compiled into the DLL

Recording Format

Binary .oxrr file, format version 1, keyed by frame index

Dependencies

OpenXR SDK headers (Apache-2.0). Catch2 for the tests only

Distribution

openxr-pose-layer-v1.0.1.zip: openxr_pose_layer.dll, its manifest, poseplay.exe, install.ps1 and uninstall.ps1

Requirements

An OpenXR app and an OpenXR runtime. No administrator rights. No VC++ redistributable: the C runtime is linked statically

Tests

40 unit tests through an in-process fake next layer, run in CI. No runtime or headset involved

Source Code

github.com/HeathHowren/openxr-pose-layer

Features

Log, record and replay modes

Call trace with per-call timings

Head pose and eye views recorded

Controller poses recorded

Boolean, float and vector2f action states

xrLocateSpaces groups (OpenXR 1.1)

Recordings keyed by frame index

No dependence on space or action handles

View poses rewritten in xrEndFrame

Replay time scale

Replay looping

Position and yaw offset

Environment variables or a config file

poseplay info, dump and trim

JSON output for scripts

Per-user install, no administrator

uninstall.ps1 to remove it

Static C runtime

40 unit tests, run in CI

Before You Download

Intended use. openxr-pose-layer is for testing and studying OpenXR apps you own or are authorized to analyze: your own apps, sample apps such as hello_xr, and development builds. Feeding recorded input into an online or competitive game may trip anti-cheat software and get the account banned, and modifying software you do not have permission to modify may be illegal where you live. This is a development and research tool.

What has been tested. The 40 unit tests drive the real layer code through an in-process fake next layer, with no OpenXR runtime and no headset. They run in CI. The output above came from that harness, not from a headset. End-to-end replay against hello_xr on a null runtime is a manual check, outside CI.

Replay replaces tracking. On real hardware, replay overrides tracking, so the scene world-locks to the recorded path and stops following your head. That is expected. To run with no headset, put a null runtime under the layer: Monado’s simulated driver or the SteamVR null driver. In record mode the file is written only when the app shuts down OpenXR. If the app crashes or is killed, nothing is saved.

The binaries are unsigned. Antivirus software may flag a new unsigned DLL that loads into other processes. Build it from source if you would rather not take a binary on trust. install.ps1 writes only under HKEY_CURRENT_USER and needs no administrator rights. uninstall.ps1 undoes it.