Six degrees of freedom (6DoF)

Degrees of freedom describe the ways an object can move. In VR the term tells you how completely a headset or controller is tracked.

3DoF: rotation only

A 3DoF device tracks rotation on three axes: looking left and right (yaw), up and down (pitch), and tilting your head toward a shoulder (roll). It cannot tell if you lean, crouch or step. Early phone-based viewers and some media headsets worked this way, which suits watching 360-degree video while seated but not active games.

6DoF: rotation plus position

A 6DoF device adds three axes of position: moving forward and back, left and right, and up and down. You can walk around a virtual object, duck under an obstacle or lean in for a closer look, and your hands appear where they really are. This is what makes room-scale VR possible and is a big factor in comfort, because the view responds to every movement of your body.

Today

All mainstream headsets and their controllers are 6DoF, whether they use inside-out tracking or base station tracking. The terms still matter when comparing cheaper viewers, video glasses and some accessories.