VTK::RenderingOpenXR#

The OpenXR module aims to support rendering to a variety of mixed reality devices under the OpenXR industry-wide standard. Detailed information on the OpenXR specification and compliant OpenXR runtimes may be found on the Khronos Group website.

Supported Devices#

The OpenXR standard is implemented by most PC-based OpenXR runtimes and devices. The VTK OpenXR module aims to support most devices that implement the OpenXR specification and support OpenGL rendering.

The list of possible XR device targets is extensive and constantly expanding. At the time of writing, theoretically supported devices include but are not limited to the following:

Valve Index
HTC Vive (, Pro)
Meta Quest (1,2,3,Pro)
- Quest Link or Air Link only
HP Reverb G2

Supported input devices and mechanisms include the following:

HP Mixed Reality Controller
HTC Vive Controller
KHR Simple Controller
Valve Knuckles
Microsoft Hand Interaction

The OpenXR module is commonly tested with the Valve Index and HTC Vive virtual reality headsets.

Adding New Devices#

It may be necessary to tell VTK how to handle inputs from a new OpenXR-compatible device. Consider contributing a new JSON input binding specification to add support for a new XR device to the VTK OpenXR module.

The OpenXR interaction profile specification is documented here:

https://registry.khronos.org/OpenXR/specs/1.0/html/xrspec.html#semantic-path-interaction-profiles

Input binding JSON files should be added to OpenXR and set as default in vtk_openxr_actions.json.

Building#

The OpenXR module depends on the OpenXR-SDK library. OpenXR-SDK can be built with CMake via the steps below:

> git clone git@github.com:KhronosGroup/OpenXR-SDK.git
> mkdir OpenXR-SDK-build
> cd OpenXR-SDK-build
OpenXR-SDK-build > cmake ../OpenXR-SDK
OpenXR-SDK-build > cmake --build . --config "Release"

The OpenXR is turned off in VTK by default. Run the following steps to build VTK with OpenXR:

VTK-build > cmake -DVTK_MODULE_ENABLE_VTK_RenderingOpenXR:STRING=YES -DOpenXR_INCLUDE_DIR:PATH="path/to/OpenXR-SDK/include/openxr" -DOpenXR_LIBRARY:FILEPATH="path/to/OpenXR-SDK-build/src/loader/Release/openxr_loader.lib" path/to/VTK
VTK-build > cmake --build . --config "Release"

Testing#

Minimum OpenXR examples are available in the Testing/Cxx directory for testing.

To run OpenXR tests, first build VTK with testing enabled.

VTK-build > cmake -DVTK_BUILD_TESTING:BOOL=ON path/to/VTK
VTK-build > cmake --build . --config "Release"

Then run the test with CTest.

VTK-build > ctest -C Release -R <name_of_test>

Additional Notes#

See VTK OpenXRRemoting documentation for information on virtual reality rendering to DirectX devices such as the Microsoft HoloLens 2.

Some non-OpenGL devices may be compatible with the WebGL and WebXR specifications. If your XR device does not support OpenGL or OpenXR, we suggest visiting VTK.js WebXR documentation for a web-driven solution.