平滑旋转门，新手入门，求指点

using System.Collections;
using System.Collections.Generic;
using UnityEngine;

public class twween : MonoBehaviour {
	private float _time;

	private bool isTrigger;

	private bool isOpen;
	// Use this for initialization
	void Start () {
		isOpen = false;
		isTrigger = false;
	}
	
	// Update is called once per frame
	void Update () {
		if (Input.GetKeyDown (KeyCode.F)) {
			isTrigger = true;

		}


	}

	void FixedUpdate()
	{
		ControlDoor ();
	}



		


	void ControlDoor()
	{
		if (isTrigger == true) {


			if (isOpen == false) {
				transform.localEulerAngles = new Vector3 (0, 
					Mathf.LerpAngle (transform.localEulerAngles.y, 90f, 0.05f), 0);
		
			} else {
				transform.localEulerAngles = new Vector3 (0, 
					Mathf.LerpAngle (transform.localEulerAngles.y, 0f, 0.05f), 0);
			
			}



		}
		if (transform.localEulerAngles.y>=85f) {
			isTrigger = false;
			isOpen = true;
		}
		if (transform.localEulerAngles.y<=0.1f) {
			isTrigger = false;
			isOpen = false;
		}
	}
}