fpsController.cs

using UnityEngine;

[RequireComponent(typeof(CharacterController))]

public class FPScontroller : MonoBehaviour
{

    [SerializeField] private Camera playerCamera;

    [Header("Speed")]
    [SerializeField] float walkSpeed = 5f;
    [SerializeField] float runSpeed = 10f;

    [Header("Vertical components")]
    [SerializeField] float jumpPower = 6f;
    [SerializeField] float gravity = 10f;

    [Header("Mouse sensitivity & look limit")]
    [SerializeField] private float lookSpeed = 2f;
    [SerializeField] private float lookXlimit = 45f;

    private Vector3 moveDirection = Vector3.zero;
    private float rotationX = 0;

    private bool canMove = true;

    private CharacterController characterController;

    void Start()
    {
        characterController = GetComponent<CharacterController>();
        Cursor.lockState = CursorLockMode.Locked;
        Cursor.visible = false;

    }

    void Update()
    {


        Vector3 forward = transform.TransformDirection(Vector3.forward);
        Vector3 right = transform.TransformDirection(Vector3.right);

        // Shift to run
        bool isRunning = Input.GetKey(KeyCode.LeftShift);
        float curSpeedX = canMove ? (isRunning ? runSpeed : walkSpeed) * Input.GetAxis("Vertical") : 0;
        float curSpeedY = canMove ? (isRunning ? runSpeed : walkSpeed) * Input.GetAxis("Horizontal") : 0;
        float movementDirectionY = moveDirection.y;
        moveDirection = (forward * curSpeedX) + (right * curSpeedY);



        if (Input.GetButton("Jump") && canMove && characterController.isGrounded)
        {
            moveDirection.y = jumpPower;
        }
        else
        {
            moveDirection.y = movementDirectionY;
        }

        if (!characterController.isGrounded)
        {
            moveDirection.y -= gravity * Time.deltaTime;
        }

        
        characterController.Move(moveDirection * Time.deltaTime);

        if (canMove)
        {
            rotationX += -Input.GetAxis("Mouse Y") * lookSpeed;
            rotationX = Mathf.Clamp(rotationX, -lookXlimit, lookXlimit);
            playerCamera.transform.localRotation = Quaternion.Euler(rotationX, 0, 0);
            transform.rotation *= Quaternion.Euler(0, Input.GetAxis("Mouse X") * lookSpeed, 0);

        }
          
    }
}