The translational components may be given in terms of movements along x-, y-, and z-axes of the head, which form a right-handed coordinate system for the head.
Rotations about around the x-, y-, and z -axes are commonly referred to as roll, pitch, and yaw, respectively
The positive direction of head rotation follows a right-hand rule—that is, if the fingers of the right hand are curled in the direction of the arrows, the thumb points in the positive direction of the axis.
Axis | Rotation | Pos. Direction | Neg. Direction |
|---|---|---|---|
x | Roll | tilt to the right | tilt to the left |
y | Pitch | nose down | nose up |
z | Yaw | turn left | turn right |
Direction are indicated relative to the heads viewing angle.