Develop Reference

How to make the bullets to be firing towards a target?

using System;
using System.Collections;
using System.Collections.Generic;
using UnityEngine;
public class ShootBullets : MonoBehaviour
{
public float bulletDistance;
public bool automaticFire = false;
public float fireRate;
public Rigidbody bullet;
private float gunheat;
private bool shoot = false;
private GameObject bulletsParent;
private GameObject[] startpos;
// Start is called before the first frame update
void Start()
{
bulletsParent = GameObject.Find("Bullets");
startpos = GameObject.FindGameObjectsWithTag("Fire Point");
}
private void Fire()
{
for (int i = 0; i < startpos.Length; i++)
{
Rigidbody bulletClone = (Rigidbody)Instantiate(bullet, startpos[i].transform.position, startpos[i].transform.rotation, bulletsParent.transform);
bulletClone.velocity = transform.forward * bulletDistance;
Destroy(bulletClone.gameObject, 0.5f);
}
}
// Update is called once per frame
void FixedUpdate()
{
if (automaticFire == false)
{
if (Input.GetMouseButtonDown(0))
{
Fire();
}
}
else
{
if (shoot == true)
{
Fire();
shoot = false;
}
}
if (gunheat > 0) gunheat -= Time.deltaTime;
if (gunheat <= 0)
{
shoot = true;
gunheat = fireRate;
}
}
}
now the bullets firing up the air and i want the bullets to fire to a target with physics.
the main goal later is to make some kind of side mission where the player third person view should shoot on object and if and when hitting the object the object will fall down and then the player will be able to pick it up.

C# spawn manager creating waves of enemies too quickly

I'm a beginner making my first game in Unity, following Unity's Create With Code course. I'm creating a shooter game that will use hand tracking. I haven't set up hand tracking yet so i created an OnTrigger input that explodes objects when I hit space. I created the spawn manager below to spawn waves of enemy attack, but they all the waves are spawning enemies too fast. It seems like they're spawning automatically instead of when the first wave has been destroyed.
Is there an easier way to spawn at a slower rate? Or spawn only when there are no more enemies alive?
EDIT: Added Attack script below
using System.Collections;
using System.Collections.Generic;
using UnityEngine;
public class SpawnAttack : MonoBehaviour
{
public GameObject Trumps;
private float spawnRange = 9;
public int enemyCount;
public int waveNumber = 1;
void Start()
{
SpawnEnemyWave(waveNumber);
//InvokeRepeating("GenerateSpawnPosition", startDelay, randomInterval);
}
// Update is called once per frame
void Update()
{
enemyCount = FindObjectsOfType<Attack>().Length;
if(enemyCount == 0)
{
waveNumber++;
SpawnEnemyWave(waveNumber);
}
}
void SpawnEnemyWave(int enemiesToSpawn)
{
for (int i = 0; i < enemiesToSpawn; i++)
{
Instantiate(Trumps, GenerateSpawnPosition(), Trumps.transform.rotation);
}
}
private Vector3 GenerateSpawnPosition()
{
float spawnPosX = Random.Range(-spawnRange, spawnRange);
float spawnPosZ = Random.Range(-spawnRange, spawnRange);
Vector3 randomPos = new Vector3(spawnPosX, 0, spawnPosZ);
return randomPos;
}
}
using System.Collections;
using System.Collections.Generic;
using UnityEngine;
public class Attack : MonoBehaviour
{
public float speed = 0.5f;
public GameObject Player;
private Rigidbody enemyRb;
// Start is called before the first frame update
void Start()
{
enemyRb = GetComponent<Rigidbody>();
Player = GameObject.Find("Player");
this.transform.LookAt(Player.transform);
}
// Update is called once per frame
void Update()
{
Vector3 lookDirection = (Player.transform.position - transform.position).normalized;
enemyRb.AddForce(lookDirection * speed);
transform.Translate(Vector3.forward * Time.deltaTime * speed);
}
private void OnTriggerEnter(Collider other)
{
Destroy(gameObject);
Debug.Log("Game Over");
}
}

I guess that you can use the invoke method:
Invoke("NameOfTheMethod", 1f)
What this method does is that it waits a certain amount of seconds before calling a method. You have to write the name of the method in quotation marks and then select how long you want to wait before the method is called (The "1f" represents the delay in seconds.) In your case, you can make the script wait before spawning enemies.

I don't know your Attack script but I would use something like
public class Attack : MonoBehaviour
{
public static readonly HashSet<Attack> AliveAttackInstances = new HashSet<Attack>();
private void Awake()
{
AliveAttackInstances.Add(this);
}
private void OnDestroy()
{
AliveAttackInstances.Remove(this);
}
}
So you can all the time in a cheaper way check how many and which enemies are alive like
public class SpawnAttack : MonoBehaviour
{
// I would change this type here to make sure your spawned prefab actually
// HAS an Attack attached .. otherwise your enemyCount will always be 0
public Attack Trumps;
...
void Update()
{
if(Attack.AliveAttackInstances.Count == 0)
{
waveNumber++;
SpawnEnemyWave(waveNumber);
}
}
Then in order to add a certain delay before spawning the next wave you could use a simple timer like
public class SpawnAttack : MonoBehaviour
{
public Attack Trumps;
[SerializeField] private float delay = 1f;
private float timer;
...
void Update()
{
if(Attack.AliveAttackInstances.Count == 0)
{
timer -= Time.deltaTime;
if(timer <= 0)
{
timer = delay;
waveNumber++;
SpawnEnemyWave(waveNumber);
}
}
}

Try to use Coroutine.
Here's a video about Coroutines: https://www.youtube.com/watch?v=qolMYyq0nX0
My example:
public class Spawn : MonoBehaviour {
private float TimeToWait = 3f;
public int enemyCount = 0;
public int waveNumber = 0;
public GameObject enemy;
void Start()
{
StartCoroutine(SpawnEnemyWave(waveNumber));
}
void Update()
{
if (enemyCount == 0)
{
waveNumber++;
StartCoroutine(SpawnEnemyWave(waveNumber));
}
if (Input.GetMouseButtonDown(0))
{
enemyCount--;
}
}
IEnumerator SpawnEnemyWave(int enemiesToSpawn)
{
//"Things to do before the seconds."
for (int i = 0; i < enemiesToSpawn; i++)
{
enemyCount++;
}
yield return new WaitForSeconds(TimeToWait); // at this example we wait 3 seconds (float TimeToWait = 3f;)
//"Things to do after the seconds."
for (int i = 0; i < enemiesToSpawn; i++)
{
Debug.Log("New Enemy!");
Instantiate(enemy, transform.position, Quaternion.identity);
}
}
}

Stone not spawning at correct place after player respawns

When the player reSpawns I want the stones(which can be moved by the player), to go to their original spot. This is not working for me. Instead, the stone spawn on other nearby locations and sometimes off the map. All stones are tagged stone.
I have tried reversing the Vectors and reversing the signs on the subtraction and such.
This is the player script.
using System.Collections;
using System.Collections.Generic;
using UnityEngine;
public class PlayerControll : MonoBehaviour
{
public bool isTouchingGround = false;
public GameObject locater1;
public GameObject locater2;
public GameObject currentCheckPoint;
public GameObject playerPrefab;
public Rigidbody2D myRigidBody;
public GameObject GameMaster;
// Start is called before the first frame update
void Start()
{
isTouchingGround = false;
GameObject MyGameMaster= Instantiate(GameMaster, new Vector3(0, 0, 0), Quaternion.identity);
GameMaster = MyGameMaster;
}
// Update is called once per frame
void Update()
{
if (Input.GetKey("a"))
{
transform.Translate(-0.1f, 0, 0);
}
if (Input.GetKey("d"))
{
transform.Translate(0.1f, 0, 0);
}
if ((Input.GetKey("w") || Input.GetKey("space")) && isTouchingGround == true)
{
myRigidBody.AddForce(new Vector2(0f, 130f));
}
if (locater1.transform.position.y <= locater2.transform.position.y)
{
ReSpawn();
}
}
private void OnCollisionEnter2D(Collision2D collision)
{
if (collision.gameObject.tag == "Platform" || collision.gameObject.tag == "Stone")
{
isTouchingGround = true;
}
}
private void OnCollisionExit2D(Collision2D collision)
{
if ((collision.gameObject.tag == "Platform" || collision.gameObject.tag == "Stone") && locater2.transform.position.y > collision.transform.position.y)
{
isTouchingGround = false;
}
}
private void OnTriggerEnter2D(Collider2D collision)
{
if (collision.gameObject.tag == "CheckPoint")
{
currentCheckPoint = collision.gameObject;
}
if (collision.gameObject.tag == "Radiation")
{
ReSpawn();
}
}
public void ReSpawn()
{
GameMaster.gameObject.GetComponent<ReverToOriginalPositions>().RevertToOrignalPosition();
GameObject currentPlayer=Instantiate(playerPrefab, currentCheckPoint.transform.position, currentCheckPoint.transform.rotation);
currentPlayer.GetComponent<PlayerControll>().isTouchingGround = false;
Destroy(this.gameObject);
}
}
This is the RememberPositions script. This belongs to every stone to remember the position is has during the start.
using System.Collections;
using System.Collections.Generic;
using UnityEngine;
public class RememberPositions : MonoBehaviour
{
public float StartXPosition;
public float StartYPosition;
float StartRotation;
// Start is called before the first frame update
void Start()
{
StartXPosition = transform.position.x;
StartYPosition = transform.position.y;
StartRotation = transform.rotation.z;
}
// Update is called once per frame
void Update()
{
}
}
this is the RevertToOriginalPosition Script. This reverts the stones to their original positions. This is in the GameMaster/MasterControll.
using System.Collections;
using System.Collections.Generic;
using UnityEngine;
public class ReverToOriginalPositions : MonoBehaviour
{
public GameObject[] allStones;
// Start is called before the first frame update
void Start()
{
allStones = GameObject.FindGameObjectsWithTag("Stone");
}
// Update is called once per frame
void Update()
{
}
public void RevertToOrignalPosition()
{
for (int i = 0; i < allStones.Length; i++)
{
allStones[i].gameObject.transform.Translate((new Vector3((allStones[i].gameObject.GetComponent<Transform>().position.x- allStones[i].gameObject.GetComponent<RememberPositions>().StartXPosition) , (allStones[i].gameObject.GetComponent<Transform>().position.y- allStones[i].gameObject.GetComponent<RememberPositions>().StartYPosition), 0)));
allStones[i].gameObject.transform.Rotate(0, 0, -allStones[i].gameObject.transform.rotation.z);
}
}
}
This is the Store reciever Script. This is for another game mechanic called an Activator. This is not that important but I am including it anyway.
using System.Collections;
using System.Collections.Generic;
using UnityEngine;
public class StoreReciever : MonoBehaviour
{
public GameObject reciever;
// Start is called before the first frame update
void Start()
{
}
// Update is called once per frame
void Update()
{
}
void OnTriggerEnter2D(Collider2D collision)
{
reciever.gameObject.GetComponent<PolygonCollider2D>().enabled = true;
}
void OnTriggerExit2D(Collider2D collision)
{
reciever.gameObject.GetComponent<PolygonCollider2D>().enabled = false;
}
}
No error messages at all. Just Stones reSpawning in locations they are not supposed to. Thank You for helping.

Just make some fields/properties they dont even have to be private static readonly
public static readonly Vector3 StartPos = new Vector3(1.0f, 2.0f, 3.0f);
public static readonly Vector3 StartRot_In_EulerAngles = new Vector3(1.0f, 2.0f, 3.0f);
Then you can do something like this in a method:
public static void ResetMyStones()
{
var allStones = GameObject.FindGameObjectsWithTag("Stone");
foreach(var stone in allStones)
{
stone.transform.position = StartPos;
stone.transform.eulerAngles = StartRot_In_EulerAngles;
}
}
About Euler Angle:
Why Euler Angle? - because for rotations Unity uses so called Quaternions, so Gimbal lock will not happen, but the bad thing about this is that you cannot really set x y z component individually without deep understanding of Quaternions, however if you just wanna set and get a current rotation Euler Angle is perfect, because you can use the traditional x,y,z components for setting the value.
Additional Notes:
Your code is kinda long and not well structured, like ReverToOriginalPositions should be a method and not a component, also not evrything has to be a derived from monobehaviour.
Also remove the unused Update methods, they have a small overhead if its in a script but not used(Usually its immeasurable but in bigger project it can effect performance :)), and maybe if your game is structured that way you could store all your current stones in a GameManager class list so you dont need to call GameObject.FindGameObjectsWithTag("Stone");

Unity 2D, C# - Why my OnCollisionEnter2D doesn't collide?

So, i created two scripts, one named "Stats.cs" registers the player stats and the other one named "PlayerHealth.cs" "makes" the player take damage on contact and updates the Hearts in the HUD. My problem is, whenever i collide with an object that has a tag named "Projectile" it simply doesn't work, my player doesn't take damage at all. The Stats.cs script isn't in any object, the PlayerHealth.cs is in my Player object.
Stats.cs
using System.Collections;
using System.Collections.Generic;
using UnityEngine;
[System.Serializable]
public class Stats{
private int health;
public int maxHP = 3;
public int Health
{
get
{
//Some code
return health;
}
set
{
//Some code
health = Mathf.Clamp(value, 0, maxHP);
}
}
public void SetHealth()
{
Health = maxHP;
}
}
PlayerHealth.cs
using System.Collections;
using System.Collections.Generic;
using UnityEngine;
using UnityEngine.UI;
public class PlayerHealth : MonoBehaviour
{
Stats playerStats = new Stats();
public int curHealth;
public int numOfHearts = 3;
public Image[] hearts;
public Sprite fullHeart;
public Sprite emptyHeart;
void OnCollisionEnter2D(Collision2D other)
{
if (other.gameObject.CompareTag("Projectile"))
{
Debug.Log("Hello");
DamagePlayer(1);
Destroy(other.gameObject);
}
}
public void DamagePlayer(int damage)
{
playerStats.Health -= damage;
}
// Start is called before the first frame update
void Start()
{
playerStats.SetHealth();
curHealth = numOfHearts;
}
// Update is called once per frame
void Update()
{
curHealth = playerStats.Health;
numOfHearts = playerStats.maxHP;
if (curHealth>numOfHearts){
curHealth = numOfHearts;
}
if(curHealth <= 0){
Die();
}
for (int i = 0; i < hearts.Length; i++)
{
if(i < curHealth){
hearts[i].sprite = fullHeart;
} else
{
hearts[i].sprite = emptyHeart;
}
if(i < numOfHearts){
hearts[i].enabled = true;
} else {
hearts[i].enabled = false;
}
}
}
void Die(){
//Restart
Application.LoadLevel(Application.loadedLevel);
}
}
curHealth is updating so it will stay as the actual Health in Stats and will change the images in HUD.
The Player has a RigidBody2D on him two colliders, one is a box for the body, and the other is a circle collider, so when the player crouches, the circle collider disables.
The Projectiles also have and RigidBody2D with 0 gravity (so it won't fall in mid air) and a BoxCollider2D.

I would check and make sure that the projectile is tagged as Projectile and that the BoxCollider doesn't have "Is Trigger" checked.
I should also say, iterating with that for loop in the Update is very bad practice performance wise. That is happening literally as fast as the machine can loop it and it is doing that every time. I would look into updating it on an event.
Hope this helps!

Next Scene Not Loading

My problem is that when all the enemies are killed the scene that should be loaded is not loading. I did add the scene to the Build setting (it has an index of 3) but it is still not loading. The script I created is attached to an empty object and not directly to the sprite (is that okay?). Can someone tell me why the scene isn't loading? Thank you.
This image is for to show you the EnemySpawner empty object inspector
EnemySpawner Script :
using System.Collections;
using System.Collections.Generic;
using UnityEngine;
using UnityEngine.UI;
public class EnemySpawner : MonoBehaviour {
[SerializeField] GameObject EnemyPreFab;
[SerializeField] int MaxEnemies = 30;
[SerializeField] float EnemySpawnTime = 1.00001f;
[SerializeField] GameObject FirstWaypoint;
int CurrentNumOfEnemies = 0;
public LevelManager myLevelManager;
public int maximumnumberofhits = 0;
int timesEnemyHit;
IEnumerator SpawningEnemies()
{
while(CurrentNumOfEnemies <= MaxEnemies)
{
GameObject Enemy = Instantiate(EnemyPreFab, this.transform.position, Quaternion.identity);
CurrentNumOfEnemies++;
yield return new WaitForSeconds(EnemySpawnTime);
}
}
void Start()
{
StartCoroutine(SpawningEnemies());
timesEnemyHit = 0;
if (this.gameObject.tag == "EnemyHit")
{
CurrentNumOfEnemies++;
}
}
void OnCollisionEnter2D()
{
timesEnemyHit++;
if (timesEnemyHit == maximumnumberofhits)
{
CurrentNumOfEnemies--;
Destroy(this.gameObject);
}
if (CurrentNumOfEnemies == 0)
{
myLevelManager.LoadLevel("NextLevelMenu");
Debug.Log("LevelLoaded");
}
}
}
LevelManger script:
using System.Collections;
using System.Collections.Generic;
using UnityEngine;
using UnityEngine.SceneManagement;
public class LevelManager : MonoBehaviour {
public void LoadLevel(string name)
{
print("Level loading requested for" + name);
SceneManager.LoadScene(name);
}
}
EnemyShooting Script :
using System.Collections;
using System.Collections.Generic;
using UnityEngine;
public class EnemyShooting : MonoBehaviour {
[SerializeField] float EnemyLaserSpeed = 10f;
[SerializeField] float EnemyLaserFireTime;
[SerializeField] GameObject LaserBulletEnemyPreFab;
[SerializeField] int MaxNumberOfHits = 1;
int CurrentNumberOfHits = 0;
Coroutine FireCoroutine;
void OnTriggerEnter2D(Collider2D collider)
{
if(collider.gameObject.tag == "PlayerLaser")
{
if(CurrentNumberOfHits < MaxNumberOfHits)
{
CurrentNumberOfHits++;
Destroy(collider.gameObject);
Score.ScoreValue += 2;//The user will be rewarded 1 point
}
}
}
void DestroyEnemy()
{
if(CurrentNumberOfHits >= MaxNumberOfHits)
{
Destroy(gameObject);
}
}
private void Fire()
{
FireCoroutine = StartCoroutine(ShootContinuously());
}
void BecomeVisible()
{
Fire();
}
IEnumerator ShootContinuously()
{
while (true)
{
GameObject LaserBulletEnemy = Instantiate(LaserBulletEnemyPreFab, this.transform.position, Quaternion.identity) as GameObject;
LaserBulletEnemy.GetComponent<Rigidbody2D>().velocity = new Vector2(0, EnemyLaserSpeed);
EnemyLaserFireTime = Random.Range(0.5f, 0.9f);
yield return new WaitForSeconds(EnemyLaserFireTime);
}
}
// Use this for initialization
void Start () {
BecomeVisible();
}
// Update is called once per frame
void Update () {
DestroyEnemy();
}
}
EnemyPathing script:
using System.Collections;
using System.Collections.Generic;
using UnityEngine;
public class EnemyPathing : MonoBehaviour {
[SerializeField] List<Transform> WayPoints;
[SerializeField] float EnemyMovingSpeed = 5f;
int WayPointIndex = 0;
void EnemyMoving()
{
if (WayPointIndex <= WayPoints.Count - 1)
{
var TargetedPosition = WayPoints[WayPointIndex].transform.position; //The position of where the enemy needs to go
TargetedPosition.z = 0f;
var MoveThisFrame = EnemyMovingSpeed * Time.deltaTime;
transform.position = Vector2.MoveTowards(this.transform.position, TargetedPosition, MoveThisFrame);
if(transform.position == TargetedPosition)
{
WayPointIndex++;
}
}
else
{
Destroy(gameObject);
}
}
// Use this for initialization
void Start () {
transform.position = WayPoints[WayPointIndex].transform.position;
}
// Update is called once per frame
void Update () {
EnemyMoving();
}
}

Problem
You're checking for collisions on the SPAWNER; when someone hits the Spawner it counts down enemies. But the Spawner doesn't have a collision box in the screenshot so it can never be hit. The Scene changing code can never be called.
So the game, based on the code, looks like this:
Spawn X enemies,
Hit the Spawner X times,
(Removed: Destroy the Spawner,)
Change scene.
I'm guessing this is conceptually incorrect and you actually want to check collisions on the spawned enemies, which will then count up the amount of destroyed enemies, and change the scene when they are all dead.
Solution
Conceptually, what you want is:
Spawn X enemies
Count up variable for every enemy
On Enemy death, count it down
When 0, change scene
So how do we code this?
Well, every enemy needs a reference to the object that holds the count. You can do this in several ways, when I personally do it I usually have just one spawner that is responsible for everyone so I make that one a Singleton, that can be references from anywhere:
EnemySpawner
public class EnemySpawner : MonoBehaviour
{
public static Spawner Instance = null;
int CurrentNumOfEnemies = 0;
// ... etc
void Start()
{
if (Instance == null)
Instance = this;
// Spawn enemies like you do already, CurrentNumOfEnemies++ for every spawned
}
public OnEnemyDeath() {
CurrentNumOfEnemies--;
if (CurrentNumOfEnemies < 1)
{
// You killed everyone, change scene:
LevelManager.LoadLevel("Your Level");
}
}
}
Enemy script (I don't know how your current code looks, but here's a minimal solution based on how I THINK your code looks):
void OnDestroy()
{
// This will run automatically when you run Destroy() on this gameObject
EnemySpawner.Instance.OnEnemyDeath(); // Tell the EnemySpawner that someone died
}
This will only work if you have exactly only ONE spawner. If you have multiple ones you will have to send a reference to the instance of its spawner to every spawned enemy. I can show you how to do ths too, if you wish.
Bonus content
LevelManager doesn't need to be on a GameObject, it can be static instead:
Remove the LevelManager script from any GameObject
Change your LevelManager code to this:
using System.Collections;
using System.Collections.Generic;
using UnityEngine;
using UnityEngine.SceneManagement;
public static class LevelManager
{
public static void LoadLevel(string name)
{
Debug.Log("Level loading requested for" + name);
SceneManager.LoadScene(name);
}
}
Now you can use it from ANYWHERE, without needing to initialize a reference to any script or GameObject:
LevelManager.LoadLevel("My Level");

myLevelManager.LoadLevel("NextLevelMenu"); is never executed, because you destroy the object in the if-test above.