Enemy Shoot Closest Object Within Shooting Range - c#

I would like the Enemy(Monster) to shoot players in Shooting Range of the Enemy and return closest players within the Range
I'm quite new to Unity and currently using Unity 2017,2D at the moment, for now.
Thanks so much for your Help Guys!
public class Monster : MonoBehaviour {
[SerializeField]
GameObject Bullet;
public float fireRate;
float nextFire;
// Use this for initialization
void Start () {
fireRate = 1f;
nextFire = Time.time;
}
// Update is called once per frame
void Update () {
CheckIfTimeToFire ();
}
void CheckIfTimeToFire()
{
if (Time.time > nextFire)
{
Instantiate (Bullet, transform.position, Quaternion.identity);
nextFire = Time.time + fireRate;
}
}
}
Here is the Bullet Script
public class Bullet : MonoBehaviour {
public float moveSpeed = 3f;
Rigidbody2D rb;
PlayerAI target;
Vector2 moveDirection;
// Use this for initialization
void Start () {
rb = GetComponent<Rigidbody2D> ();
target = GameObject.FindObjectOfType<PlayerAI>();
moveDirection = (target.transform.position - transform.position).normalized * moveSpeed;
rb.velocity = new Vector2 (moveDirection.x, moveDirection.y);
Destroy (this.gameObject, 2);
}
void OnTriggerEnter2D (Collider2D col)
{
if (col.gameObject.name.Equals ("Player"))
{
Debug.Log ("Hit!");
Destroy (gameObject);
}
}
}

Assuming you have a small number of players, a convenient method would be to hold a reference to players as a collection and iterate to get transform.position of each player. Then you can check the distance to the monster to get the minimum distance.
I also suggest doing the logical check on Monster rather than on Bullet, and pass target to Bullet. So that you can choose not to instantiate a bullet if no player is in range.
public class Monster : MonoBehaviour
{
...
public float range;
private PlayerAI[] players;
...
private void Awake()
{
players = FindObjectsOfType<PlayerAI>();
}
...
private void CheckIfTimeToFire()
{
if (Time.time < nextFire)
{
return;
}
PlayerAI closestPlayer = null;
float closestPlayerDistance = float.MaxValue;
foreach (PlayerAI player in players)
{
float playerDistance = Vector3.Distance(transform.position, player.transform.position);
if (playerDistance > range ||
playerDistance > closestPlayerDistance)
{
// Skip to next player.
continue;
}
closestPlayer = player;
closestPlayerDistance = playerDistance;
}
if (closestPlayer == null)
{
// No player in range. Do nothing.
return;
}
GameObject bullet = Instantiate (Bullet, transform.position, Quaternion.identity);
bullet.GetComponent<Bullet>().Initialize(closestPlayer.transform);
nextFire = Time.time + fireRate;
}
...
}
public class Bullet : MonoBehaviour
{
...
private Transform target;
...
public void Initialize(Transform target)
{
this.target = target;
}
...
}
In the example, I get the players on Awake() of a Monster, but if you are instantiating them in runtime you can hold the PlayerAI collection in a separate manager class. In this case a list could be more useful.
public void PlayerManager : MonoBehaviour
{
public List<PlayerAI> Players { get; private set; }
...
private void Awake()
{
while (playerCount < totalPlayerCount)
{
SpawnPlayer();
}
}
private void SpawnPlayer()
{
PlayerAI player = Instantiate(player, ...);
Players.Add(player);
}
// Remove a dead player, etc.
private void OnPlayerDied(PlayerAI player)
{
Players.Remove(player);
}
...
}
public class Monster : MonoBehaviour
{
...
private PlayerManager playerManager;
...
private void Awake()
{
playerManager = FindObjectOfType<PlayerManager>();
}
void CheckIfTimeToFire()
{
...
foreach (PlayerAI player in playerManager.Players)
{
...
}
...
}
}

Related

GameObject not being removed from List?

I've tried 2/3 different ways of removing my gameObject from my List but none are working. When I debug the method the debug log is showing up as it should yet the gameobject still isn't removed from the list.
When my teammates kill an enemy I want the enemy to be removed from the list and then destroyed so I can continue to iterate through the List to find the closest enemy to begin attacking. Because the gameObject's are not being removed I get a null reference and i can loop through my for loop to check.
1st Script: List is created and used in a for loop, removing and destroying the enemy also occurs in here.
public class FriendlyManager : MonoBehaviour
{
public NavMeshAgent navMeshAgent;
public Transform player;
public static FriendlyManager singleton;
public float health;
public float minimumDistance;
public int damage;
public List<GameObject> enemies;
private GameObject enemy;
private GameObject enemyObj;
// animations
[SerializeField] Animator animator;
bool isAttacking;
bool isPatroling;
// attacking
[SerializeField] Transform attackPoint;
[SerializeField] public GameObject projectile;
public float timeBetweenAttacks;
bool alreadyAttacked;
private void Awake()
{
navMeshAgent = GetComponent<NavMeshAgent>();
animator = GetComponent<Animator>();
enemyObj = new GameObject();
}
private void Start()
{
singleton = this;
isAttacking = false;
isPatroling = true;
animator.SetBool("isPatroling", true);
}
private void Update()
{
for(int i = 0; i < enemies.Count; i++)
{
if(Vector3.Distance(player.transform.position, enemies[i].transform.position) <= minimumDistance)
{
enemy = enemies[i];
Attacking(enemy);
}
}
}
private void Attacking(GameObject enemy)
{
// stop enemy movement.
navMeshAgent.SetDestination(transform.position);
enemyObj.transform.position = enemy.transform.position;
transform.LookAt(enemyObj.transform);
if (!alreadyAttacked)
{
isAttacking = true;
animator.SetBool("isAttacking", true);
animator.SetBool("isPatroling", false);
Rigidbody rb = Instantiate(projectile, attackPoint.position, Quaternion.identity).GetComponent<Rigidbody>();
rb.AddForce(transform.forward * 32f, ForceMode.Impulse);
alreadyAttacked = true;
Invoke(nameof(ResetAttack), timeBetweenAttacks);
}
}
private void ResetAttack()
{
alreadyAttacked = false;
animator.SetBool("isAttacking", false);
}
public void DestroyEnemy(GameObject enemy)
{
enemies.Remove(enemy);
Debug.Log("AHHHHHHH M GOING CRAZY");
Destroy(gameObject);
}
}
}
2nd Script: Deals with the damage and checks enemy's currentHealth. (I have to post it as an image because for Stack Overflow is being annoying.) ._.
Shouldn't it just be
Destroy(enemy);
and not
Destroy(gameObject);

Vector3 is being reset to 0,0,0 Unity

I'm making a game right now where the enemies become alerted to the player and chase them indefinetely until the player stand on a "safe plate" in game. When the player stands here the enemies should then return to their original position.
The issue is that whenever the player stands on the plate I get a null reference exception error and I can see the original guard position has been reset to 0,0,0 in the console. I'm assuming the reason for the null reference exception is because the world origin isn't on the nav mesh I'm using, although I could easily be wrong about that. I just can't seem to figure out why the vector3 value has changed at all since the guardPosition variable is initiated on Start and never touched again.
I've included both my enemyAi class (script attached to enemy) and my class associated with stepping on plates. If there's anything more needed to include let me know. If anyone has any ideas, help would be appreciated. Cheers.
Screenshot on console after stepping on plate
public class EnemyAI : MonoBehaviour
{
DeathHandler dh;
[SerializeField] Transform target;
[SerializeField] float chaseRange = 5f;
[SerializeField] float killRange = 2f;
[SerializeField] GameObject explosionEffect;
NavMeshAgent navMeshAgent;
float distanceToTarget = Mathf.Infinity;
bool isDead = false;
bool isAlert = false;
Vector3 guardPosition;
void Start()
{
GameObject gob;
gob = GameObject.Find("Player");
dh = gob.GetComponent<DeathHandler>();
guardPosition = transform.position;
navMeshAgent = GetComponent<NavMeshAgent>();
}
void Update()
{
distanceToTarget = Vector3.Distance(target.position, transform.position);
print(guardPosition + " guard position during update");
//alert a dude
if (distanceToTarget <= chaseRange && !isDead)
{
isAlert = true;
}
//chase a dude
if (isAlert == true)
{
ChasePlayer();
print(isAlert);
}
}
public void ChasePlayer()
{
navMeshAgent.SetDestination(target.position);
//explode a dude
if (distanceToTarget <= killRange)
{
Explode();
dh.KillPlayer();
}
}
public void SetAlertStatus(bool status)
{
isAlert = status;
}
public void ReturnToPost()
{
//isAlert = false;
print(guardPosition + " guard position after stepping on plate");
navMeshAgent.SetDestination(guardPosition);
}
void Explode()
{
Instantiate(explosionEffect, transform.position, transform.rotation);
isDead = true;
Destroy(gameObject);
}
void OnDrawGizmosSelected()
{
Gizmos.color = Color.red;
Gizmos.DrawWireSphere(transform.position, chaseRange);
}
}
public class SafeSpots : MonoBehaviour
{
EnemyAI enemyAi;
void Start()
{
GameObject gob;
gob = GameObject.FindGameObjectWithTag("Enemy");
enemyAi = gob.GetComponent<EnemyAI>();
}
public void OnTriggerStay(Collider other)
{
if (other.gameObject.tag == "Player")
{
enemyAi.SetAlertStatus(false);
enemyAi.ReturnToPost();
}
}
}
You are getting a disabled instance of EnemyAI. Instead, use FindGameObjectsWithTag then iterate through all of them and add their EnemyAI to a list which you can iterate through when necessary. By the way, it's better to use CompareTag when possible to reduce garbage:
public class SafeSpots : MonoBehaviour
{
List<EnemyAI> enemyAis;
void Start()
{
GameObject[] enemies= GameObject.FindGameObjectsWithTag("Enemy");
enemyAis = new List<EnemyAI>();
foreach (GameObject enemy in enemies)
{
enemyAis.Add(enemy.GetComponent<EnemyAI>());
}
}
public void OnTriggerStay(Collider other)
{
if (other.CompareTag("Player"))
{
foreach(EnemyAI enemyAi in enemyAis)
{
enemyAi.SetAlertStatus(false);
enemyAi.ReturnToPost();
}
}
}
}

How do I make my player speed up when collide with a game object in Unity?

I am doing a school project in Unity. My team and I decided to make an endless runner 2D game. However, because it is the first time I use C#, I don't know how to make my player's speed accelerate when collide with a game object in Unity. I only know how to destroy the player's health when a collision happens. Please help me! Thank you!
it's quite hard to give answers without seeing any code you've written, but as it's 2D and you've already got the collision damage working, you've probably used an OnCollisionEnter(), well it's very similar: you test if you've collided (which you've already done), then you add force to your player using a rigidbody2d, probably something along the lines of:
public Rigidbody2D rb;
void OnCollisionEnter2D(Collision2D collision)
{
rb.AddForce(direction * force, ForceMode2D.Impulse); // the ForceMode2D is
// optional, it's just so that
// the velocity change is sudden.
}
This should work.
If you have a GameManager that stores the game speed you can also do that too:
private float gameSpeedMultiplier = 0.5f;
void OnCollisionEnter(Collision collision)
{
if(collision.gameObject.CompareTag("Tag of the collided object")
{
GameManager.Instance.gameSpeed += gameSpeedMultiplier;
}
}
public class PlayerContoler : MonoBehaviour
{
public static PlayerContoler instance;
public float moveSpeed;
public Rigidbody2D theRB;
public float jumpForce;
private bool isGrounded;
public Transform GroundCheckPoint;
public LayerMask whatIsGround;
private bool canDoubleJump;
private Animator anim;
private SpriteRenderer theSR;
public float KnockbackLength, KnockbackForce;
private float KnockbackCounter;
public float bonceForce;
public bool stopImput;
private void Awake()
{
instance = this;
}
// Start is called before the first frame update
void Start()
{
anim = GetComponent<Animator>();
theSR = GetComponent<SpriteRenderer>();
}
// Update is called once per frame
void Update()
{
if(!PauseMenu.instance.isPause && !stopImput)
{
if (KnockbackCounter <= 0)
{
theRB.velocity = new Vector2(moveSpeed * Input.GetAxis("Horizontal"), theRB.velocity.y);
isGrounded = Physics2D.OverlapCircle(GroundCheckPoint.position, .2f, whatIsGround);
if (isGrounded)
{
canDoubleJump = true;
}
if (Input.GetButtonDown("Jump"))
{
if (isGrounded)
{
theRB.velocity = new Vector2(theRB.velocity.x, jumpForce);
AudioManager.instance.PlaySFX(10);
}
else
{
if (canDoubleJump)
{
theRB.velocity = new Vector2(theRB.velocity.x, jumpForce);
canDoubleJump = false;
AudioManager.instance.PlaySFX(10);
}
}
}
if (theRB.velocity.x < 0)
{
theSR.flipX = true;
}
else if (theRB.velocity.x > 0)
{
theSR.flipX = false;
}
} else
{
KnockbackCounter -= Time.deltaTime;
if(!theSR.flipX)
{
theRB.velocity = new Vector2(-KnockbackForce, theRB.velocity.y);
} else
{
theRB.velocity = new Vector2(KnockbackForce, theRB.velocity.y);
}
}
}
anim.SetFloat("moveSpeed", Mathf.Abs(theRB.velocity.x));
anim.SetBool("isGrounded", isGrounded);
}
public void Knockback()
{
KnockbackCounter = KnockbackLength;
theRB.velocity = new Vector2(0f, KnockbackForce);
anim.SetTrigger("hurt");
}
}

I am trying to do a score that increase on ball collision with brick

I am doing a game in Unity for a school project.
I need to increase the score when the ball collides with brick. What I am doing wrong please? Below is the code that I tried to use. Score starts at zero but never goes more than 1. Any help of how I can fix this issue please?
public class Brick : MonoBehaviour
{
public int hitPoint = 3;
public GameObject explosion;
public GameObject heart;
[Range(0f, 1f)]
public float percentage;
float randNum;
public float fallSpeed = 8.0f;
public Sprite OneHits;
public Sprite TwoHits;
public Sprite ThreeHits;
public Text ScoreText;
private int points;
GameObject ball;
void Start()
{
ball = GameObject.FindGameObjectWithTag("ball");
}
void Update()
{
ScoreText.text = "Score " + points ;
randNum = Random.Range(0f, 1f);
if (hitPoint == 1)
{
this.GetComponent<SpriteRenderer>().sprite = OneHits;
}
if (hitPoint == 2)
{
this.GetComponent<SpriteRenderer>().sprite = TwoHits;
}
if (hitPoint == 3)
{
this.GetComponent<SpriteRenderer>().sprite = ThreeHits;
}
}
private void OnCollisionEnter(Collision collision)
{
if (collision.gameObject.tag == "ball")
{
ball = collision.gameObject;
hitPoint--;
points++;
if (hitPoint <= 0)
{
Destroy(this.gameObject);
Instantiate(explosion, transform.position, transform.rotation);
if (randNum < percentage)
{
Instantiate(heart, transform.position, transform.rotation);
}
}
}
}
}
There are a couple of things wrong with your code.
If you destroy the game object the script is running on the script will stop, so I would move your destroy command to the end of your method.
I am guessing that you dont want points to be different for each brick, I would move points to another class called scoreboard or something. For the time being I made points static. This means that only one copy of this variable exists and if one brick adds a point it gets reflected across all bricks.
using System.Collections;
using System.Collections.Generic;
using UnityEngine;
using UnityEngine.UI;
public class Test : MonoBehaviour
{
public int hitPoint = 3;
public GameObject explosion;
public GameObject heart;
[Range(0f, 1f)]
public float percentage;
float randNum;
public float fallSpeed = 8.0f;
public Sprite OneHits;
public Sprite TwoHits;
public Sprite ThreeHits;
public Text ScoreText;
public static int points;
GameObject ball;
void Start()
{
ball = GameObject.FindGameObjectWithTag("ball");
}
void Update()
{
ScoreText.text = "Score " + points;
randNum = Random.Range(0f, 1f);
if (hitPoint == 1)
{
this.GetComponent<SpriteRenderer>().sprite = OneHits;
}
if (hitPoint == 2)
{
this.GetComponent<SpriteRenderer>().sprite = TwoHits;
}
if (hitPoint == 3)
{
this.GetComponent<SpriteRenderer>().sprite = ThreeHits;
}
}
private void OnCollisionEnter(Collision collision)
{
if (collision.gameObject.CompareTag("ball"))
{
ball = collision.gameObject;
hitPoint--;
points++;
if (hitPoint <= 0)
{
Instantiate(explosion, transform.position, transform.rotation);
if (randNum < percentage)
{
Instantiate(heart, transform.position, transform.rotation);
}
Destroy(gameObject);
}
}
}
}

How to change player speed with public float from another script

Hey I am trying to change a float when my player collides with a object. I tried many ways of reference but only got null when trying to debug I came up with this so far. I want to get the gameobject that contains the player script meaning the player and after I want to get the component script tankmovement to change the variable in it.
Getting the null reference error in the powerups script line 79 reset function Tank=GameObject.FindWithTag("Player")
using System.Collections.Generic;
using UnityEngine;
public class PowerUp : MonoBehaviour {
public bool boosting = false;
public GameObject effect;
public AudioSource clip;
public GameObject Tank;
private void Start()
{
Tank = GameObject.Find("Tank(Clone)");
TankMovement script = GetComponent<TankMovement>();
}
private void OnTriggerEnter(Collider other)
{
if (other.gameObject.CompareTag("Player"))
{
if (!boosting)
{
clip.Play();
GameObject explosion = Instantiate(effect, transform.position, transform.rotation);
Destroy(explosion, 2);
GetComponent<MeshRenderer>().enabled = false;
GetComponent<Collider>().enabled = false;
Tank.GetComponent<TankMovement>().m_Speed = 20f;
//TankMovement.m_Speed = 20f;
boosting = true;
Debug.Log(boosting);
StartCoroutine(coolDown());
}
}
private IEnumerator coolDown()
{
if (boosting == true)
{
yield return new WaitForSeconds(4);
{
boosting = false;
GetComponent<MeshRenderer>().enabled = true;
GetComponent<Collider>().enabled = true;
Debug.Log(boosting);
// Destroy(gameObject);
}
}
}
void reset()
{
//TankMovement.m_Speed = 12f;
TankMovement collidedMovement = Tank.gameObject.GetComponent<TankMovement>();
collidedMovement.m_Speed = 12f;
//TankMovement1.m_Speed1 = 12f;
}
}
}
Trying to call on my m_Speed float in the player script to boost the speed of my player when he collides with it. How would you get a proper reference since my player is a prefab.
Tank script
using UnityEngine;
public class TankMovement : MonoBehaviour
{
public int m_PlayerNumber = 1;
public float m_Speed = 12f;
public float m_TurnSpeed = 180f;
public AudioSource m_MovementAudio;
public AudioClip m_EngineIdling;
public AudioClip m_EngineDriving;
public float m_PitchRange = 0.2f;
private string m_MovementAxisName;
private string m_TurnAxisName;
private Rigidbody m_Rigidbody;
private float m_MovementInputValue;
private float m_TurnInputValue;
private float m_OriginalPitch;
private void Awake()
{
m_Rigidbody = GetComponent<Rigidbody>();
}
private void OnEnable ()
{
m_Rigidbody.isKinematic = false;
m_MovementInputValue = 0f;
m_TurnInputValue = 0f;
}
private void OnDisable ()
{
m_Rigidbody.isKinematic = true;
}
private void Start()
{
m_MovementAxisName = "Vertical" + m_PlayerNumber;
m_TurnAxisName = "Horizontal" + m_PlayerNumber;
m_OriginalPitch = m_MovementAudio.pitch;
}
private void Update()
{
// Store the player's input and make sure the audio for the engine is playing.
m_MovementInputValue = Input.GetAxis(m_MovementAxisName);
m_TurnInputValue = Input.GetAxis(m_TurnAxisName);
EngineAudio();
}
private void EngineAudio()
{
// Play the correct audio clip based on whether or not the tank is moving and what audio is currently playing.
if (Mathf.Abs(m_MovementInputValue) < 0.1f && Mathf.Abs(m_TurnInputValue) < 0.1f)
{
if (m_MovementAudio.clip == m_EngineDriving)
{
m_MovementAudio.clip = m_EngineIdling;
m_MovementAudio.pitch = Random.Range(m_OriginalPitch - m_PitchRange, m_OriginalPitch + m_PitchRange);
m_MovementAudio.Play();
}
}
else
{
if (m_MovementAudio.clip == m_EngineIdling)
{
m_MovementAudio.clip = m_EngineDriving;
m_MovementAudio.pitch = Random.Range(m_OriginalPitch - m_PitchRange, m_OriginalPitch + m_PitchRange);
m_MovementAudio.Play();
}
}
}
private void FixedUpdate()
{
// Move and turn the tank.
Move();
Turn();
}
private void Move()
{
// Adjust the position of the tank based on the player's input.
Vector3 movement = transform.forward * m_MovementInputValue * m_Speed * Time.deltaTime;
m_Rigidbody.MovePosition(m_Rigidbody.position + movement);
}
private void Turn()
{
// Adjust the rotation of the tank based on the player's input.
float turn = m_TurnInputValue * m_TurnSpeed * Time.deltaTime;
Quaternion turnRotation = Quaternion.Euler(0f, turn, 0);
m_Rigidbody.MoveRotation(m_Rigidbody.rotation * turnRotation);
}
}
Since the TankMovement component you need to access is attached to the GameObject that is colliding with the power, you can get the TankMovement component you need to change by using other.gameObject.GetComponent<TankMovement>():
private void OnTriggerEnter(Collider other)
{
if (other.gameObject.CompareTag("Player"))
{
if (!boosting)
{
// stuff
TankMovement collidedMovement = other.gameObject.GetComponent<TankMovement>();
collidedMovement.m_Speed = 20f;
// more stuff
}
}
}

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