Unity XR is a cross-platform development platform for Unity which allows developers to easily develop for both VR and Mixed Reality. Unity remains the most popular platform for VR development, used for more than 90% of projects.
Introduced last year, the Unity XR framework used common middle-ware and plugins which would allow developers to easily add support for different VR platforms, with the usual Write One, Run Anywhere promise.
The plugins included those for the HoloLens, Windows Mixed Reality, Oculus, AR Core etc.
In their latest release Unity announced that they are dropping support for Samsung’s Gear VR and Google VR, saying:
Gear VR is no longer supported in 2019.3 and beyond, as Oculus focuses on their current generation of hardware.
Google VR is no longer supported in 2019.3 and beyond due to Google ending sales of Daydream View and the launch of the Cardboard Open Source Project.
OpenVR is no longer a Unity supported platform in 2019.3 and beyond. Valve is developing their OpenVR XR plugin for 2019.3, and they will share more information on where to access it once it is available.
Regarding OpenVR Unity said:
As part of our shift to the new plugin framework, Valve is using our XR SDK to develop their OpenVR Unity XR plugin for 2019.3 and beyond. They will share more information on where to access it once it is available. Until that plugin is available, built-in support of OpenVR will continue to be functional and available in 2019.3, and we will support our users with any critical fixes.
As noted above, Google had itself signalled the end of that platform by halting DayDream headset sales, and formally announced it on October 2019.
Gear VR, Google VR, and OpenVR will remain supported in Unity 2018 LTS.
Despite not setting the world on fire, Windows Mixed Reality remains supported, including support for the well-received HoloLens headset.
Developers can read more about the updated platform plugins at Unity here.