CameraControllerv2.cs

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

public class CameraControllerv2 : MonoBehaviour
{
    [SerializeField]
    private Transform player;

    private Vector3 offset; 
    private Vector3 setPosition;

    private Vector3 angle;
    //Radians
    private float deg = 0;
    
    //Radius
    private float r=5;
    
    [SerializeField]//Height adjustment
    public float height;
    Transform rootTransform;
    float beforeY;

    void Start () {
    	//Initialize Camera Position Setting
    	offset = transform.position - player.transform.position;
    	offset.y += height;
    	setPosition = player.transform.position += offset;
	transform.position = setPosition;

        //Initialize Look Position
        transform.LookAt(player.transform.position);
	angle = transform.eulerAngles;

        rootTransform = player.transform.root;
        beforeY = rootTransform.eulerAngles.y;

        //Lock Cursor
        Cursor.visible = false;
        Cursor.lockState = CursorLockMode.Locked;
		
    }
	

    // Update is called once per frame
    void Update () {
       	//End Play
       	if(Input.GetKey(KeyCode.Escape))UnityEditor.EditorApplication.isPlaying = false;
		
	float horizontal ;
	float vertical ;
        float rootY  = rootTransform.eulerAngles.y-beforeY;
        
	horizontal = Input.GetAxis("Mouse X")*10f;
	vertical = Input.GetAxis("Mouse Y")*2;
        
        if(beforeY > rootY)deg-=rootY;
        if(beforeY < rootY)deg+=rootY;

	if(0 < Input.mousePosition.x)deg += horizontal;

	if(0 > Input.mousePosition.x)deg -= horizontal;

	if(0 < Input.mousePosition.y)angle.x += vertical;

	if(0 > Input.mousePosition.y)angle.x -= vertical;

        //Position Calculation X
	setPosition.x = player.transform.position.x +r*  Mathf.Cos(Mathf.Deg2Rad*deg);
	setPosition.y = player.transform.position.y + offset.y;
	setPosition.z = player.transform.position.z +r* Mathf.Sin(Mathf.Deg2Rad*deg);

        //Position Change
	transform.position = setPosition;

        beforeY = rootTransform.eulerAngles.y;
        //LookAt playerTransform + angleY
	transform.LookAt(new Vector3(player.transform.position.x,player.transform.position.y + angle.x,player.transform.position.z));
	}

}