Leap Motion created gesture control for all sorts of things, including virtual reality, long ago, but developers must build in support for their tracking peripheral to use its full potential. As a result, they've created an "Interaction Engine" for Unity, the primary platform for developing virtual and mixed reality experiences, to try and take gesture interaction to the next level.
You're probably wondering what's an Interaction Engine, exactly? Leap Motion explains:
The Interaction Engine is a layer that exists between the Unity game engine and real-world hand physics. To make object interactions work in a way that satisfies human expectations, it implements an alternate set of physics rules that take over when your hands are embedded inside a virtual object.
If you could summarize the benefits of Leap Motion's effort in one word, it'd be precision. Without the Interaction Engine, picking up objects in virtual and mixed reality can often result in a fumble or feel very unnatural. With the engine on, however, natural gestures provide precise results that our human minds understand and expect.
In a lot of ways, it brings an interaction model seemingly similar to Meta's approach. Rather than relying solely on existing user experience paradigms on computers, Leap Motion considers normal human behavior and assumptions as the primary inspiration for their toolset. Or, at least, it sure looks that way in their many examples.