In the ever-evolving quest to never have to take our VR headsets off, Valve recently released a new feature for Index users that can accurately project the room around you in 3D space.
The goal of the feature, called Room View 3D, is to give a more precise representation of the user's environment for moments when you'd otherwise need to take the headset off. Valve's announcement post doesn't go into detail about how it works, but people who have tried it speculate that it's using the Index's multiple cameras to build a live 3D environment.
Most of the comments I saw seem pretty impressed with it so far, despite some wonkiness. Steam user rsk said that Room View 3D is cool when it works, but that it's "very jittery and unstable" right now. That's to be expected of a new feature, though I'd imagine you could get quickly disoriented if the world started to jitter around you.
Maybe the biggest rub for Room View 3D right now is its exclusivity to the Valve Index. It'd be great to see the feature cleaned up and become a standard of VR headsets someday in the future.