I am currently working on a small project (FPS) in unity for learning purposes. I implemented an EnemyBehaviour script to handle the logic of the enemy when it is in the scene. This worked pretty well so long as it was only one enemy. But when I spawned in only 4 enemies, I could see that the fps are contstantly dropping. I start out at around 160fps and it eventually goes down to like 27fps. I am not sure why exactly this happens but here is what I did.
First I tried with every enemy clone having their own MonoBehaviour script attached and independently of each other carry out the behaviour, with the following code:
public class EnemyBehaviour : MonoBehaviour
{
[SerializeField] private float _moveSpeed;
[SerializeField] private GameObject _projectilePrefab;
private Rigidbody _rb;
private BoxCollider _collider;
private float _randomX;
private float _randomZ;
private float _xBoundUpper = -263f;
private float _zBoundUpper = 60f;
private float _xBoundUnder = -411f;
private float _zBoundUnder = -90f;
private float _middleY;
private bool _canWalk;
private bool _targetPointInBounds;
private bool _playerInRange;
private bool _hasFired;
private bool _isAttacking;
private Vector3 _targetPoint;
private Vector3 _enemyCenter;
private Vector3 _playerCenter;
private GameObject _player;
private CapsuleCollider _playerCollider;
private void Awake()
{
_rb = GetComponent<Rigidbody>();
_collider = GetComponent<BoxCollider>();
_player = GameObject.Find("Player");
_playerCollider = _player.GetComponent<CapsuleCollider>();
}
private void Update()
{
_enemyCenter = this.transform.TransformPoint(_collider.center);
_middleY = _enemyCenter.y;
_playerCenter = _player.transform.TransformPoint(_playerCollider.center);
WalkToRandomPoint();
StartCoroutine(AttackPlayer());
}
private void WalkToRandomPoint()
{
if (!_canWalk && !_playerInRange)
{
_targetPointInBounds = false;
while (!_targetPointInBounds)
{
_randomX = Random.Range(-1f, 1f);
if (_randomX < 0)
{
_randomZ = -1 - _randomX;
}
else
{
_randomZ = 1 - _randomX;
}
Vector3 rayForwardDirection = transform.TransformDirection(new Vector3(_randomX, -0.05f, _randomZ));
Ray ray = new Ray(_enemyCenter, rayForwardDirection);
RaycastHit hit;
if (Physics.Raycast(ray.origin, ray.direction, out hit, Mathf.Infinity))
{
Debug.DrawRay(ray.origin, ray.direction * hit.distance, Color.red);
_targetPoint = new Vector3(hit.point.x, _middleY, hit.point.z);
}
if(_xBoundUnder <= _targetPoint.x && _targetPoint.x <= _xBoundUpper
&& _zBoundUnder <= _targetPoint.z && _targetPoint.z <= _zBoundUpper)
{
_targetPointInBounds = true;
} else
{
_targetPointInBounds = false;
}
}
_canWalk = true;
} else if (_canWalk)
{
transform.LookAt(_targetPoint);
_rb.MovePosition(this.transform.position + transform.TransformDirection(Vector3.forward) * _moveSpeed * Time.fixedDeltaTime);
if((_targetPoint.x - 1) <= transform.position.x && transform.position.x <= (_targetPoint.x + 1)
&& (_targetPoint.z -1) <= transform.position.z && transform.position.z <= (_targetPoint.z + 1) && !_playerInRange)
{
_canWalk = false;
}
}
GoToPlayer();
}
/// <summary>
/// Checks wether the player is in sight distance and if so sets player as new target point
/// </summary>
private void GoToPlayer()
{
int layerMask = 1 << 7;
Ray rayToPlayer = new Ray(_enemyCenter, (_playerCenter - _enemyCenter));
Debug.DrawRay(rayToPlayer.origin, rayToPlayer.direction * 100, Color.yellow);
RaycastHit hit;
if(Physics.Raycast(rayToPlayer, out hit, Mathf.Infinity, layerMask))
{
if(hit.distance <= 100)
{
_playerInRange = true;
_targetPoint = _playerCenter;
if(hit.distance <= 30)
{
transform.LookAt(_targetPoint);
_canWalk = false;
if (hit.distance <= 10)
{
_rb.MovePosition(this.transform.position + transform.TransformDirection(-1 * Vector3.forward) * _moveSpeed * Time.fixedDeltaTime);
}
} else
{
_canWalk = true;
}
} else
{
_playerInRange = false;
}
}
}
private IEnumerator AttackPlayer()
{
while (_playerInRange)
{
if (!_hasFired)
{
Instantiate(_projectilePrefab, _enemyCenter, this.transform.rotation);
_hasFired = true;
yield return new WaitForSeconds(2f);
_hasFired = false;
} else
{
yield return null;
}
}
}
}
As performance there seemed to drop really fast I thought maybe it would be better to create an EnemyManager script which finds all enemies in the scene, puts them in an array and then carries out the logic at every iteration, with this code:
public class EnemyManager : MonoBehaviour
{
[SerializeField] private float _moveSpeed;
[SerializeField] private GameObject _projectilePrefab;
private Rigidbody _rb;
private BoxCollider _collider;
private float _randomX;
private float _randomZ;
private float _xBoundUpper = -263f;
private float _zBoundUpper = 60f;
private float _xBoundUnder = -411f;
private float _zBoundUnder = -90f;
private float _middleY;
private bool _canWalk;
private bool _targetPointInBounds;
private bool _playerInRange;
private bool _hasFired;
private bool _isAttacking;
private bool _startOfGame;
private Vector3 _targetPoint;
private Vector3 _enemyCenter;
private Vector3 _playerCenter;
private GameObject _player;
private GameObject _activeEnemy;
private CapsuleCollider _playerCollider;
private GameObject[] enemiesOnScene;
private void Awake()
{
enemiesOnScene = GameObject.FindGameObjectsWithTag("Enemy");
_player = GameObject.Find("Player");
_playerCollider = _player.GetComponent<CapsuleCollider>();
_startOfGame = true;
}
private void Update()
{
for(int i = 0; i <= enemiesOnScene.Length; i++)
{
_activeEnemy = enemiesOnScene[i];
_rb = _activeEnemy .GetComponent<Rigidbody>();
_collider = _activeEnemy.GetComponent<BoxCollider>();
if (_startOfGame)
{
StartCoroutine(AttackPlayer());
_startOfGame = false;
}
_enemyCenter = _activeEnemy.transform.TransformPoint(_collider.center);
_middleY = _enemyCenter.y;
_playerCenter = _player.transform.TransformPoint(_playerCollider.center);
WalkToRandomPoint();
}
}
private void WalkToRandomPoint()
{
if (!_canWalk && !_playerInRange)
{
_targetPointInBounds = false;
while (!_targetPointInBounds)
{
_randomX = Random.Range(-1f, 1f);
if (_randomX < 0)
{
_randomZ = -1 - _randomX;
}
else
{
_randomZ = 1 - _randomX;
}
Vector3 rayForwardDirection = _activeEnemy.transform.TransformDirection(new Vector3(_randomX, -0.05f, _randomZ));
Ray ray = new Ray(_enemyCenter, rayForwardDirection);
RaycastHit hit;
if (Physics.Raycast(ray.origin, ray.direction, out hit, Mathf.Infinity))
{
Debug.DrawRay(ray.origin, ray.direction * hit.distance, Color.red);
_targetPoint = new Vector3(hit.point.x, _middleY, hit.point.z);
}
if (_xBoundUnder <= _targetPoint.x && _targetPoint.x <= _xBoundUpper
&& _zBoundUnder <= _targetPoint.z && _targetPoint.z <= _zBoundUpper)
{
_targetPointInBounds = true;
}
else
{
_targetPointInBounds = false;
}
}
_canWalk = true;
}
else if (_canWalk)
{
_activeEnemy.transform.LookAt(_targetPoint);
_rb.MovePosition(_activeEnemy.transform.position + _activeEnemy.transform.TransformDirection(Vector3.forward) * _moveSpeed * Time.fixedDeltaTime);
if ((_targetPoint.x - 1) <= transform.position.x && transform.position.x <= (_targetPoint.x + 1)
&& (_targetPoint.z - 1) <= transform.position.z && transform.position.z <= (_targetPoint.z + 1) && !_playerInRange)
{
_canWalk = false;
}
}
GoToPlayer();
}
/// <summary>
/// Checks wether the player is in sight distance and if so sets player as new target point
/// </summary>
private void GoToPlayer()
{
int layerMask = 1 << 7;
Ray rayToPlayer = new Ray(_enemyCenter, (_playerCenter - _enemyCenter));
Debug.DrawRay(rayToPlayer.origin, rayToPlayer.direction * 100, Color.yellow);
RaycastHit hit;
if (Physics.Raycast(rayToPlayer, out hit, Mathf.Infinity, layerMask))
{
if (hit.distance <= 100)
{
_playerInRange = true;
_targetPoint = _playerCenter;
if (hit.distance <= 30)
{
_activeEnemy.transform.LookAt(_targetPoint);
_canWalk = false;
if (hit.distance <= 10)
{
_rb.MovePosition(_activeEnemy.transform.position + _activeEnemy.transform.TransformDirection(-1 * Vector3.forward) * _moveSpeed * Time.fixedDeltaTime);
}
}
else
{
_canWalk = true;
}
}
else
{
_playerInRange = false;
}
}
}
private IEnumerator AttackPlayer()
{
while (_playerInRange)
{
if (!_hasFired)
{
Instantiate(_projectilePrefab, _enemyCenter, _activeEnemy.transform.rotation);
_hasFired = true;
yield return new WaitForSeconds(2f);
_hasFired = false;
}
else
{
yield return null;
}
}
}
}
Here, the frame rate drops not as fast but it still drops. When looking at the profiler I saw that the coroutine takes up most of the CPU’s capacity, at least I think that is what it says.
Screenshot of the profiler
Does anyone have any suggestions on how to make this more efficient?
Thank you so much in advance!
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