Unity - Di chuyen theo vi tri click chuot

using UnityEngine;
using System.Collections;

public class theLastOneBehaviour : MonoBehaviour {

    private Vector3 clickPos;  // vi tri click left mouse

    // Use this for initialization
    void Start () {
        clickPos = transform.position;
    }

    // Update is called once per frame
    void Update () {
        MovetheLastOne ();
    }

    void MovetheLastOne(){
        // bat su kien click chuot trai
        if (Input.GetMouseButton (0)) {
            // Camera.main.ScreenToWorldPoint --> Chuyen Toa do man hinh thanh toa do 3 chieu
            // Input.mousePosition --> Lay toa do man hinh
            clickPos = Camera.main.ScreenToWorldPoint(Input.mousePosition);
        }

        // di chuyen tu vi tri hien tai toi clickPos
        transform.position = Vector3.MoveTowards (transform.position, clickPos, Time.deltaTime * 3.0f);
    }
}