TankController

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

public class TankController : MonoBehaviour
{
    private Rigidbody _tankRigidbody;
    private GameObject _barrel;
    private GameObject _turret;
    private GameObject _barrelEnd;

    [SerializeField] private float _movementForce = 10f;
    [SerializeField] private float _turnSpeed = 5f;
    [SerializeField] private float _projectileForce = 10f;

    [SerializeField] private Camera _mainCamera;

    private void Awake()
    {
        _tankRigidbody = gameObject.GetComponent<Rigidbody>();
        _turret = gameObject.transform.GetChild(1).gameObject;
        _barrel = _turret.transform.GetChild(0).gameObject;
        _barrelEnd = _barrel.transform.GetChild(0).gameObject;
        _mainCamera = FindObjectOfType<Camera>();
    }

    // Update is called once per frame
    void Update()
    {
        if (Input.GetKeyDown(KeyCode.Space))
        {
            Fire();
        }

        TurretLookAtMouse();
    }

    private void FixedUpdate()
    {
        if(Input.GetKey(KeyCode.W))
        {
            _tankRigidbody.AddForce(_movementForce * transform.forward);
        }

        if (Input.GetKey(KeyCode.S))
        {
            _tankRigidbody.AddForce(_movementForce * -transform.forward);
        }

        if (Input.GetKey(KeyCode.D))
        {
            transform.Rotate(_turnSpeed * Vector3.up);
        }

        if (Input.GetKey(KeyCode.A))
        {
            transform.Rotate(_turnSpeed * Vector3.down);
        }
    }

    private void TurretLookAtMouse()
    {
        Ray _cameraRay = _mainCamera.ScreenPointToRay(Input.mousePosition);
        Plane _groundPlane = new Plane(Vector3.up, Vector3.zero);

        if (_groundPlane.Raycast(_cameraRay, out float _rayLength))
        {
            Vector3 _pointToLook = _cameraRay.GetPoint(_rayLength);
            Debug.DrawLine(_cameraRay.origin, _pointToLook, Color.blue);

            _turret.transform.LookAt(new Vector3(_pointToLook.x, _turret.transform.position.y, _pointToLook.z));
        }
    }

    private void Fire()
    {
        GameObject bullet = ObjectPool.SharedInstance.GetPooledObject();
        if (bullet != null)
        {
            bullet.transform.position = _barrelEnd.transform.position;
            bullet.transform.rotation = _barrelEnd.transform.rotation;

            bullet.SetActive(true);
            // Change back to bullet.transform.forward, once rotations are sorted out...
            bullet.GetComponent<Rigidbody>().AddForce(bullet.transform.up * _projectileForce, ForceMode.Impulse);
        }
    }

}