unity实现摄像头跟随

using UnityEngine;
using System.Collections;
 
public class FllowTarget : MonoBehaviour {
 
  public Transform character;  //摄像机要跟随的人物
  public float smoothTime = 0.01f; //摄像机平滑移动的时间
  private Vector3 cameraVelocity = Vector3.zero;
  private Camera mainCamera; //主摄像机（有时候会在工程中有多个摄像机，但是只能有一个主摄像机吧）
  
  void Awake () 
  { 
   mainCamera = Camera.main;
  }
 
  void Update()
  {
    transform.position = Vector3.SmoothDamp(transform.position, character.position + new Vector3(0, 0, -5), ref cameraVelocity, smoothTime);
  }
  
}