slerpQuaternions( qa, qb, t ) {

		return this.copy( qa ).slerp( qb, t );

	}
Performs a spherical linear interpolation between the given quaternions
and stores the result in this quaternion.

@param {Quaternion} qa - The source quaternion.
@param {Quaternion} qb - The target quaternion.
@param {number} t - The interpolation factor in the closed interval `[0, 1]`.
@return {Quaternion} A reference to this quaternion.