How can i rotate the camera with the mouse around the player ?

[Chocolade]

Now when i move the mouse around it’s rotating the camera but when the player is walking and i rotate the camera it will not follow the player i can rotate anywhere.

What i want to to now is to change it so when i move the mouse around it will rotate the camera around the player when he walk or idle so i can look the player face or back look up down but always around the player.

using UnityEngine;
using System.Collections;

public class CameraMover : MonoBehaviour
{
    public float speedH = 2.0f;
    public float speedV = 2.0f;
    private float yaw = 0.0f;
    private float pitch = 0.0f;

    public Transform playerTransform;
    public Transform mainCameraTransform = null;
    private Vector3 cameraOffset = Vector3.zero;
    public float turnSpeed = 3;

    void Start()
    {
        mainCameraTransform = Camera.main.transform;
        //Get camera-player Transform Offset that will be used to move the camera 
        cameraOffset = mainCameraTransform.position - playerTransform.position;
    }

    void LateUpdate()
    {
        //Move the camera to the position of the playerTransform with the offset that was saved in the begining
        mainCameraTransform.position = playerTransform.position + cameraOffset;

        yaw += speedH * Input.GetAxis("Mouse X");
        pitch -= speedV * Input.GetAxis("Mouse Y");
        mainCameraTransform.eulerAngles = new Vector3(pitch, yaw, 0.0f);
    }
}

I tried to add after the line with the eulerAngles a line with LookAt:

mainCameraTransform.LookAt(playerTransform.position);

But then the rotation with the mouse is not working at all.

[Chocolade]

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