A Windows-first C# XR engine and editor, built on .NET 10. Ships a desktop editor, a dedicated server, and a separate legacy OpenVR companion app for VR/desktop switching without restarting the main game.

This is early-stage software — APIs change often and there's no backward-compatibility promise yet. The goal is to get the architecture right before v1.

If you want the fastest way in: build the editor, launch the Unit Testing World, and use that as your main validation loop.

• Rendering: OpenGL 4.6 via Silk.NET is the primary path. WIP Vulkan and DX12 backends exist but only Vulkan development is ongoing.
• Physics: PhysX (via MagicPhysX) is the current default with character controller support. Jolt is planned as the future default but isn't fully integrated currently. Jitter 2 is on the roadmap for lightweight use cases, such as VTubing.
• Audio: OpenAL (Soft) via Silk.NET, with NAudio and LAME for codec support. Video audio goes through FFmpeg.
• Scene graph: Traditional scene node tree with an attached component model. Nodes form a parent-child transform hierarchy, and components derive from XRBase for change tracking.
• Animation: Skeletal animation with blend support, humanoid IK (VRIK for VR), and Assimp-based clip import.
• Asset import: FBX uses the native XREngine.Fbx importer and glTF/GLB uses the native XREngine.Gltf importer by default. Other model formats still load through Assimp (via AssimpNetter).
• Networking: Client/server realtime transport with entity replication and pose sync for multiplayer testing.
• XR: OpenXR and SteamVR/OpenVR paths. OpenVR works, and OpenXR is still in the debugging phase.
• Editor UI: ImGui is the day-to-day interface. A native UI pipeline is under development as the intended production UI.
• Input: Silk.NET.Input for keyboard, mouse, and gamepad. GLFW for windowing.
• Video/media: FFmpeg (via FFmpeg.AutoGen) for video textures, streaming, and audio extraction.

• .NET 10 SDK
• Windows 10/11 with an OpenGL 4.6 capable GPU
• Git (submodules are used for third-party deps)
• LunarG Vulkan SDK with VULKAN_SDK set, used to build the VMA native bridge
• Visual Studio 2022 or Build Tools with Desktop development with C++, used for native bridge builds
• Optional: SteamVR or an OpenXR headset for XR testing

git clone --recurse-submodules https://github.com/BlackJaxDev/XRENGINE.git
cd XRENGINE

If you already cloned without --recurse-submodules:

git submodule sync --recursive
git submodule update --init --recursive

Or use the convenience script: ./Tools/Initialize-Submodules.bat

dotnet restore
dotnet build XRENGINE.slnx

If you want the broadest one-command repo setup instead, run ExecTool --bootstrap.

For bootstrap scope, first-time setup, and what still needs manual installation afterward, see docs/features/bootstrap.md.

dotnet run --project .\XREngine.Editor\XREngine.Editor.csproj

Or: ./Tools/Start-Editor.bat

To boot into the Unit Testing World, use the Editor (Unit Testing World) launch profile in VS Code, or run the editor with --unit-testing.

If you are contributing code, the best follow-up docs are docs/features/unit-testing-world.md and docs/architecture/getting-started-in-codebase.md.

The repo includes ready-to-go .vscode/ configs. Use Run and Debug (Ctrl+Shift+D) to pick a launch profile:

• Editor (Default World) / Editor (Unit Testing World)
• Debug Client, Debug Server, Debug VRClient

There are also no-debug tasks under Terminal → Run Task for the common editor, server, client, and networking scenarios.

To export the code-defined default render pipeline as an .xrs script, run the Export-DefaultRenderPipelineScript task. The editor executable also supports --export-default-render-pipeline-script --render-pipeline-script-output <path> as a one-shot CLI command.

Debug VRClient is mainly for the legacy OpenVR path. OpenVR cannot be cleanly shut down and restarted inside the same running app, so XREngine.VRClient exists to hold that SteamVR connection in a separate process. The main engine app can then stay alive and switch between desktop and VR gameplay without forcing a full restart. OpenXR does not have that limitation, so this extra process is specifically for legacy OpenVR support.

Open XRENGINE.slnx, set your startup project (XREngine.Editor, XREngine.Server, etc.), and hit F5. Environment variables like XRE_NET_MODE and XRE_WORLD_MODE can be set in Project → Properties → Debug to switch between server/client/local modes.

If you are working on the legacy OpenVR path, use XREngine.VRClient as the companion process rather than treating it like a second copy of the main game. It collects VR-side player input and sends it to the main engine app over a pipe, while the engine streams back the left/right eye renders for presentation through SteamVR/OpenVR.

./Tools/Start-NetworkTest.bat              # dedicated server + two clients
./Tools/Start-NetworkTest.bat mismatch     # one good client + one rejected world-hash mismatch
./Tools/Start-NetworkTest.bat pose         # server + pose source + pose receiver

The repo root has ExecTool.bat, an interactive menu for all the scripts under Tools/ — build helpers, dependency installers, report generators, and more. Run it with no arguments for the menu, or ExecTool --bootstrap for full first-time setup.

Texture sample downloaders are available there too. pwsh Tools/Get-PixelFurnaceTextures.ps1 pulls Pixel-Furnace samples, and pwsh Tools/Get-FreePbrTextures.ps1 pulls FreePBR bl texture ZIPs into Build\CommonAssets\Textures\Samples\FreePBR; review each source site's terms before redistributing downloaded assets. In the ImGui editor, open Tools > External Texture Browser or View > External Texture Browser to browse Pixel-Furnace and FreePBR preview tiles and download individual material packs into the game assets folder.

The editor's test world is configured through the generated local file Assets/UnitTestingWorldSettings.jsonc. Launch with --unit-testing (or set XRE_WORLD_MODE=UnitTesting) to boot into it. The file is intentionally ignored by Git for per-workstation tuning, and has a JSON schema wired up in VS Code for autocompletion and hover docs.

For startup model imports that reference textures outside the authored folder layout, set TextureLoadDirSearchPaths in that file to provide recursive texture search roots.

For the full workflow, including pose/network test setups and how the JSONC file is used, see docs/features/unit-testing-world.md.

ExecTool --bootstrap creates the file on first setup. To create it manually or regenerate the schema after changing the settings type:

pwsh Tools/Generate-UnitTestingWorldSettings.ps1

Most core native pieces are already wired into the build, but some optional tools and SDKs still need local setup.

For the practical setup and rebuild guide, see docs/features/native-dependencies.md.

When file logging is enabled, per-session logs go to Build/Logs/<configuration>_<tfm>/<platform>/<session>/, including profiler traces and benchmark output.

See docs/README.md for the full index — architecture overviews, API guides, rendering notes, and design docs. Key starting points:

• docs/architecture/README.md — runtime flow, threading, project layout
• docs/architecture/getting-started-in-codebase.md — contributor-oriented map of where to start
• docs/api/ — system-level API guides (scene, components, animation, physics, rendering, VR)
• docs/features/bootstrap.md — first-time setup and bootstrap scope
• docs/features/native-dependencies.md — native and external setup reference
• docs/work/README.md — active TODOs and design workstreams

No formal CONTRIBUTING.md yet. Open an issue or discussion first, then submit a PR. Active areas: rendering backends, XR tooling, editor UX, and automated testing.

If you are getting oriented in the codebase, start with docs/architecture/getting-started-in-codebase.md.

Licensed under AGPLv3. See LICENSE for the full terms.

The short version: you can use, modify, and redistribute the code, but any distribution (including network use) must stay under AGPLv3 and provide source. Third-party dependencies have their own licenses — see docs/DEPENDENCIES.md for the full inventory.

• Issues: https://github.com/BlackJaxDev/XRENGINE/issues
• Discussions: https://github.com/BlackJaxDev/XRENGINE/discussions