CameraRigController.cs

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

public class CameraRigController : MonoBehaviour
{
    public float moveSpeed;
    public float moveTime;
    public float rotationAmount;
    public float zoomAmount;

    public Transform cameraPosition;
    public Quaternion newRotation;
    
    public Vector3 newPosition;
    public Vector3 newZoom;
    
    // mouse rotato
    public Vector3 rotateStartPosition;
    public Quaternion rotateCurrentPosition;

    private float z;
    private float y;
    void Start()
    {
        newPosition = transform.position;
        newRotation = transform.rotation;
        newZoom = cameraPosition.localPosition;
    }
    
    void LateUpdate()
    {
        HandleMovementInput();        
    }

    void HandleMovementInput()
    {
        // Zoom
        if (Input.mouseScrollDelta.y !=0)
        {
            newZoom.x += Input.mouseScrollDelta.y * zoomAmount;
        }
        
        // Pan
        if (Input.GetMouseButton(1))
        {
            z = Input.GetAxis("Mouse X") * moveSpeed;
            y = -Input.GetAxis("Mouse Y") * moveSpeed;
            
            newPosition.z += z;
            newPosition.y += y;
        }
        
        // Rotate
        if (Input.GetMouseButton(0))
        {
            z += Input.GetAxis("Mouse X") * rotationAmount;
            y += Input.GetAxis("Mouse Y") * rotationAmount;
            
            newRotation = Quaternion.Euler(0,z,y);
            rotateCurrentPosition = newRotation;
        }

        transform.position = newPosition;
        transform.rotation = newRotation;
        cameraPosition.localPosition = Vector3.Lerp(cameraPosition.localPosition, newZoom, Time.deltaTime * moveTime);
    }
}