How far are we from interactivity in VR?

GUEST: There’s an oft-cited quote of Walt Disney’s: “It’s kind of fun to do the impossible.” Were he alive today, it would be interesting to see what he’d make of – and with – modern virtual reality (VR) systems.
All VR requires a basic core functionality: The ability to deliver an environment that matches perception. In the simplest VR, a view is presented to the user. If they look down, they see an image of the floor. Look up, they see sky. Done