PlayerController

using UnityEngine;

public class PlayerController : MonoBehaviour {

    private static PlayerController _me;
    public static PlayerController Me {
        get {
            if (_me == null)
                _me = GameObject.FindObjectOfType<PlayerController>();
            return _me;
        }
    }

    public float speed;
    public float jumpHeight;
    public float gravity = 20f;

    public float crouchHeight = 0.9f;
    public float crouchCameraHeight = 0.6f;
    public float crouchTransitionSmooth = 5f;

    [Space]

    public Transform cameraTransform;
    public float horizontalSensitivity = 1f;
    public float verticalSensitivity = 1f;
    public float pitchMin = -70f;
    public float pitchMax = 80f;

    [Space]

    public LayerMask playerLayer;
    public Transform aimPoint;

    private CharacterController _controller;
    private Health _health;
    private Vector3 _input;
    private Vector3 _verticalVelocity;
    private Vector3 _yawVector;
    private Vector3 _currentPitch;

    private PlayerHUD _playerHud;
    private float _standingHeight;
    private float _standingCameraHeight;

    private void Start() {
        _me = this;

        _controller = GetComponent<CharacterController>();
        _currentPitch = cameraTransform.localEulerAngles;
        _standingHeight = _controller.height;

        _standingCameraHeight = cameraTransform.position.y;

        _health = GetComponent<Health>();
        _health.OnDeathEvent.AddListener(Endgame);

        _playerHud = FindObjectOfType<PlayerHUD>();
        _playerHud.SetMouseLocked(true);
        _health.healthBar = _playerHud.HealthBar;
    }

    private void Update() {
        CrouchUpdate();
        MoveUpdate();
        LookUpdate();
    }

    private void MoveUpdate() {
        bool isGrounded = _controller.isGrounded;

        _input.x = Input.GetAxisRaw("Horizontal");
        _input.z = Input.GetAxisRaw("Vertical");
        _input.Normalize();

        if (_verticalVelocity.y < -2f && isGrounded)
            _verticalVelocity.y = -1f;

        Vector3 moveVector = transform.forward * _input.z + transform.right * _input.x;
        _controller.Move(speed * Time.deltaTime * moveVector);

        if (Input.GetKeyDown(KeyCode.Space) && isGrounded) {
            _verticalVelocity.y = Mathf.Sqrt(jumpHeight * 2f * gravity);
        }

        _verticalVelocity.y -= gravity * Time.deltaTime;
        _controller.Move(_verticalVelocity * Time.deltaTime);
    }

    private void LookUpdate() {
        _yawVector.y = Input.GetAxis("Mouse X") * horizontalSensitivity;
        float pitch = Input.GetAxis("Mouse Y") * verticalSensitivity;

        transform.Rotate(_yawVector);

        _currentPitch.x = Mathf.Clamp(_currentPitch.x - pitch, pitchMin, pitchMax);
        cameraTransform.localEulerAngles = _currentPitch;
    }

    private void CrouchUpdate() {
        bool crouching = _controller.isGrounded && Input.GetKey(KeyCode.LeftControl);
        float targetHeight = crouching ? crouchHeight : _standingHeight;
        Vector3 cameraTarget = new Vector3(0f,crouching ? crouchCameraHeight : _standingCameraHeight, 0f);

        _controller.height = Mathf.Lerp(_controller.height, targetHeight, crouchTransitionSmooth * Time.deltaTime);
        _controller.center = new Vector3(0f,_controller.height / 2, 0f);

        cameraTransform.localPosition = Vector3.Lerp(cameraTransform.localPosition, cameraTarget, crouchTransitionSmooth * Time.deltaTime);

        // call animator
    }

    private void Endgame() {
        Time.timeScale = 0f;
        _playerHud.GameOver();
    }
}