toAngleAxis

Converts this quaternion to its equivalent angle-axis representation, with the angle returned in degrees.

The quaternion is first normalized internally. If the quaternion has a near-zero length (norm squared < 1e-12f), it's treated as an identity rotation, returning an angle of 0.0 degrees and a default Z-axis (0,0,1).

For non-zero quaternions, the conversion ensures that the scalar part (w) of the normalized quaternion used for internal radian angle calculation is non-negative. This results in the radian angle being in [0, PI], which is then converted to degrees, yielding an angle in the range [0, 180] degrees.

If the calculated rotation angle is very close to zero (specifically, if sin(radian_angle/2) is less than 1e-6f), an angle of 0.0 degrees and a default Z-axis are returned.