UNITY 3D IK

    public Vector3 offset_target;
    private Animator mAnimator;
    public Transform target;

    Vector3 targetPosition;
    Vector3 dampVelocity;

    // Use this for initialization
    void Start () {
        mAnimator = GetComponent<Animator>();

    }

    void Update () {

    }

    void OnAnimatorIK() {
        if (activeIK == false) {
            mAnimator.SetLookAtWeight (0, 0, 0, 0, 0);

        }
          else {
            targetPosition = Vector3.SmoothDamp(targetPosition, target.position, ref dampVelocity, 0.2f);
            mAnimator.SetLookAtPosition (target.position);
            mAnimator.SetLookAtWeight (1, 1 , 1, 1, 1);

        }

    }