Move Controller

    public CharacterController controller;
    public Transform cam;

    public float speed;

    public float turnSmoothTime = 0.1f;

//------------EDIT---------------

//set Gravitasi nya
    private float gravity = 9.8f;
    private float verticalVelocity;

    private Vector3 moveDir = Vector3.zero;

//---------------------------

    float turnSmoothVelocity;



    void Update()
    {
        float horiz = Input.GetAxisRaw("Horizontal");
        float vertic = Input.GetAxisRaw("Vertical");
        Vector3 direction = new Vector3(horiz, 0f, vertic).normalized;

        //------------EDIT---------------

        // cek grounded gak?
        if (characterController.isGrounded )
        {
            //kalo iya jangan di tarik
            verticalVelocity = 0f;
        }
        else
        {
            //klo nga, ditarik gravitasi
            verticalVelocity -= gravity * Time.deltaTime;
        }

        //---------------------------

        if(direction.magnitude >= 0.1f)
        {
            float targetAngle = Mathf.Atan2(direction.x, direction.z) * Mathf.Rad2Deg + cam.eulerAngles.y;
            float angle = Mathf.SmoothDampAngle(transform.eulerAngles.y, targetAngle, ref turnSmoothVelocity, turnSmoothTime);
            transform.rotation = Quaternion.Euler(0f, angle, 0f);

            moveDir = Quaternion.Euler(0f, targetAngle, 0f) * Vector3.forward;

        }

        //---------EDIT------------------
        else
        {
            moveDir = Vector3.zero;
        }

        //masukin gravitasinya
        moveDir.y = verticalVelocity;
        controller.Move(moveDir.normalized * speed * Time.deltaTime);
        //---------------------------

    }