Quaternion vs Euler Rotation

Watch how a plane and its normal vector are reoriented in 3D space, using two different rotation representations.

Euler Angles

roll: 0.0  pitch: 0.0  yaw: 0.0

Quaternion

w: 1.0  x: 0.0  y: 0.0  z: 0.0
Euler controls (degrees)
Quaternion controls (axis + angle)

Tip: set Pitch close to 90° and try changing Roll and Yaw — notice how the Euler panel loses a degree of freedom (gimbal lock), while the quaternion panel doesn't.