Hand tracking estimates the position and movement of a user's hands, allowing an experience to interpret gestures without relying only on handheld controllers.
From a visible hand to an interaction
A system may estimate joints and a hand pose from camera or sensor data. The application then decides what movements mean: a pinch might select an object, for example. Detecting a hand and designing a clear interaction are separate tasks.
An exhibition example
A visitor could turn a virtual object or select an interpretation with a gesture. Good design makes the available action visible and gives feedback when it has been recognised.
What can make it difficult?
Hands may move out of the sensors' view, cover each other or be partly hidden by an object. Lighting and hardware can also affect tracking. Support for hand tracking does not guarantee reliable recognition of every gesture.
Provide another way to interact
Visitors have different abilities, reach and comfort levels. An experience should not require a precise gesture when a button, controller or guided alternative can accomplish the same task. Verify support on the intended device rather than assuming a standard phone browser includes it.