question: public void toAxisAngle ( Vector4f output ) { if ( getW ( ) > 1 ) { normalise ( ) ; } float angle = 2 * ( float ) Math . toDegrees ( Math . acos ( getW ( ) ) ) ; float x ; float y ; float z ; float s = ( float ) Math . sqrt ( 1 - getW ( ) * getW ( ) ) ; if ( s < 0.001 ) { x = points [ 0 ] ; y = points [ 1 ] ; z = points [ 2 ] ; } else { x = points [ 0 ] / s ; y = points [ 1 ] / s ; z = points [ 2 ] / s ; } output . points [ 0 ] = x ; output . points [ 1 ] = y ; output . points [ 2 ] = z ; output . points [ 3 ] = angle ; }
target:  Get an axis angle representation of this quaternion.