ALVR Support on Mac though SteamVR macOS beta

[asingueb]

For those who didn't know, there's an option in "Properties" on SteamVR that lets you use beta versions of SteamVR, and some of those betas are compatible with Mac. An ALVR program on Mac would be helpful to use different types of VR Headsets with SteamVR on Mac.

[zmerp]

That version of SteamVR is too old for ALVR needs. And frame grabbing will likely not work and this is also the most difficult part that we had to face for Linux support (we need to inject code into SteamVR compositor using a Vulkan layer and then grab the Vulkan Image and pose matrix using libunwind). There is no chance macos can have the same amount of development time.