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Unity 2d game Player and enemy not moving

I have been following a tutorial on a unity 2d game. The player and the enemy inherit from a base class known as MovingObject. Everything in the game works fine except that the player and the enemy can't move. Here are the scripts. The movement happens in a gridlike tile system.
This is the original tutorial series. Try going over the moving object, player, and enemy tutorials.
https://www.youtube.com/playlist?list=PLX2vGYjWbI0SKsNH5Rkpxvxr1dPE0Lw8F
Base MovingObject class:
using System.Collections;
using System.Collections.Generic;
using UnityEngine;
public abstract class MovingObject : MonoBehaviour {
public float moveTime = 0.1f;
public LayerMask blockinglayer;
private BoxCollider2D boxCollider;
private Rigidbody2D rb2D;
private float inverseMoveTime;
// Use this for initialization
protected virtual void Start () {
boxCollider = GetComponent<BoxCollider2D>();
rb2D = GetComponent<Rigidbody2D>();
inverseMoveTime = 1f / moveTime;
}
protected bool Move(int xDir, int yDir, out RaycastHit2D hit)
{
Vector2 start = transform.position;
Vector2 end = start + new Vector2(xDir, yDir);
boxCollider.enabled = false;
hit = Physics2D.Linecast(start, end, blockinglayer);
boxCollider.enabled = true;
if (hit.transform == null)
{
StartCoroutine(SmoothMovement(end));
return true;
}
return false;
}
protected IEnumerator SmoothMovement(Vector3 end)
{
float sqrRemainingDistance = (transform.position - end).sqrMagnitude;
while (sqrRemainingDistance > float.Epsilon)
{
Vector3 newPosition = Vector3.MoveTowards(rb2D.position, end, inverseMoveTime * Time.deltaTime);
rb2D.MovePosition(newPosition);
sqrRemainingDistance = (transform.position - end).sqrMagnitude;
yield return null;
}
}
protected virtual void AttemptMove<T>(int xDir, int yDir)
where T : Component
{
RaycastHit2D hit;
bool canMove= Move(xDir, yDir, out hit);
if (hit.transform == null)
{
return;
}
T hitComponent = hit.transform.GetComponent<T>();
if(!canMove && hitComponent != null)
{
OnCantMove(hitComponent);
}
}
protected abstract void OnCantMove<T>(T component)
where T : Component;
// Update is called once per frame
}
Player Script:
using System.Collections;
using System.Collections.Generic;
using UnityEngine;
using UnityEngine.SceneManagement;
public class Player : MovingObject {
public int wallDamage = 1;
public int pointsPerFood = 10;
public int pointsPerSoda = 20;
public float restartLevelDelay = 1f;
private Animator animator;
private int food;
// Use this for initialization
protected override void Start () {
animator = GetComponent<Animator>();
food = GameManager.instance.playerFoodPoints;
base.Start();
}
private void OnDisable()
{
GameManager.instance.playerFoodPoints = food;
}
// Update is called once per frame
void Update () {
if (GameManager.instance.playersTurn)
{
return;
}
int horizontal = 0;
int vertical = 0;
horizontal = (int)Input.GetAxisRaw("Horizontal");
vertical = (int)Input.GetAxisRaw("Vertical");
if (horizontal != 0)
{
vertical = 0;
}
if(horizontal!=0 || vertical != 0)
{
AttemptMove<Wall>(horizontal, vertical);
}
}
protected override void OnCantMove<T>(T component)
{
Wall hitwall = component as Wall;
hitwall.damageWall(wallDamage);
animator.SetTrigger("playerChop");
}
protected override void AttemptMove<T>(int xDir, int yDir)
{
food--;
base.AttemptMove<T>(xDir, yDir);
RaycastHit2D hit;
CheckIfGameOver();
GameManager.instance.playersTurn = false;
}
public void LoseFood(int loss)
{
animator.SetTrigger("playerHit");
food -= loss;
CheckIfGameOver();
}
private void OnTriggerEnter2D(Collider2D other)
{
if (other.tag == "Exit")
{
Invoke("Restart", restartLevelDelay);
enabled = false;
}
else if (other.tag == "Food")
{
food += pointsPerFood;
other.gameObject.SetActive(false);
}
else if (other.tag == "Soda")
{
food += pointsPerSoda;
other.gameObject.SetActive(false);
}
}
private void Restart()
{
SceneManager.LoadScene(SceneManager.GetActiveScene().buildIndex);
}
private void CheckIfGameOver()
{
if (food <= 0)
{
GameManager.instance.GameOver();
}
}
}
Enemy Script:
using System.Collections;
using System.Collections.Generic;
using UnityEngine;
public class Enemy : MovingObject {
public int playerDamage;
private Animator animator;
private Transform target;
private bool skipmove;
// Use this for initialization
protected override void Start () {
GameManager.instance.AddEnemyToList(this);
animator = GetComponent<Animator>();
target = GameObject.FindGameObjectWithTag("Player").transform;
base.Start();
}
protected override void AttemptMove<T>(int xDir, int yDir)
{
if (skipmove)
{
skipmove = false;
return;
}
base.AttemptMove<T>(xDir, yDir);
}
public void MoveEnemy()
{
int xDir = 0;
int yDir = 0;
if (Mathf.Abs(target.position.x - transform.position.x) < float.Epsilon)
{
yDir = target.position.y > transform.position.y ? 1 : -1;
}
else
{
xDir = target.position.x > transform.position.x ? 1 : -1;
AttemptMove<Player>(xDir,yDir);
}
}
protected override void OnCantMove<T>(T component)
{
Player hitplayer = component as Player;
animator.SetTrigger("enemyAttack");
hitplayer.LoseFood(playerDamage);
}
}
I'm not sure which whether the player or enemy have an issue of the base script. Can anyone help.

A few Observations (Hopefully it helps):
MovingObject.cs - Inside of Update(), should it not be this?
if (!GameManager.instance.playersTurn)
Note I added a "!" before GameManager
Player.cs - in AttemptMove(), you need to call Move()... like this
Move (xDir, yDir, out hit);
Enemy.cs
1) At the end of AttemptMove(), there should be:
skipMove = true;
2) In MoveEnemy(), at the end, this code should NOT be in the else, but after the else:
AttemptMove<Player>(xDir,yDir);

How can I instantiate game objects in Unity (C#) along with an instantiated integer?

I'm trying to have health points to the instantiated enemies of my game.
At first the enemies were just destroyed as soon as a single shot hit them.
I thought adding a new class just holding the HP of the instantiated prefab would work, but I don't know how to write that correctly. Either it's "static" and then I know how to call it from the bullet controller class, but it's not instantiated and the same int value is kept for all instantiated enemies, or it is not "static" and then I don't know how to call it from the other classes.
Here is the code currently, for the bullet controller:
using System.Collections;
using System.Collections.Generic;
using UnityEngine;
public class BulletController : MonoBehaviour
{
private Transform bullet;
public float speed;
// Start is called before the first frame update
void Start()
{
bullet = GetComponent<Transform>();
}
void FixedUpdate()
{
bullet.position += transform.up * speed;
if (bullet.position.y >= 10)
Destroy(gameObject);
}
void OnTriggerEnter2D(Collider2D other)
{
if (other.tag == "Enemy")
{
Enemy4HP.health--;
Destroy(gameObject);
if (Enemy4HP.health < 1)
{
Destroy(other.gameObject);
PlayerScore.playerScore++;
}
}
if (other.tag == "Enemy2")
{
Enemy10HP.health--;
Destroy(gameObject);
if (Enemy10HP.health <1)
{
Destroy(other.gameObject);
PlayerScore.playerScore++;
}
}
}
}
and for the two health classes:
using System.Collections;
using System.Collections.Generic;
using UnityEngine;
public class Enemy4HP : MonoBehaviour
{
public int health = 4;
// Start is called before the first frame update
void Start()
{
}
// Update is called once per frame
void Update()
{
}
}
using System.Collections;
using System.Collections.Generic;
using UnityEngine;
public class Enemy10HP : MonoBehaviour
{
public int health = 10;
// Start is called before the first frame update
void Start()
{
}
// Update is called once per frame
void Update()
{
}
}
And this is how the enemies get instantiated:
using System.Collections;
using System.Collections.Generic;
using UnityEngine;
using UnityEngine.UI;
public class EnemyController : MonoBehaviour
{
private Transform enemyHolder;
public float speed;
public GameObject shot;
public GameObject enemy;
public GameObject enemy2;
public Text winText;
int secCount;
float timer = 0;
public float fireRate = 0.997f;
public int enemyCount;
// Start is called before the first frame update
void Start()
{
enemyCount = 0;
secCount = 0;
enemyHolder = GetComponent<Transform>();
winText.enabled = false;
InvokeRepeating("MoveEnemy", 0f, 0.016f);
}
private List<GameObject> allSpawns = new List<GameObject>();
void MoveEnemy()
{
float xPosition = Random.Range(-11f, 11f);
int enemyType = Random.Range(0, 8);
secCount = Random.Range(2, 4);
timer += Time.deltaTime;
if (timer >= secCount && enemyCount < 25)
{
if (enemyType > 0)
{
GameObject spawned = Instantiate(enemy, new Vector3(xPosition, 6, 0), Quaternion.identity);
allSpawns.Add(spawned);
}
else
{
GameObject spawned = Instantiate(enemy2, new Vector3(xPosition, 6, 0), Quaternion.identity);
allSpawns.Add(spawned);
}
enemyCount++;
timer = timer - secCount;
}
foreach (GameObject thisEnemy in allSpawns)
{
if (thisEnemy !=null)
{
thisEnemy.transform.position += new Vector3(0, -1 * speed * Time.deltaTime, 0);
}
}
if (PlayerScore.playerScore == 25)
{
timer = 0;
CancelInvoke();
InvokeRepeating("MoveEnemy2", 0f, 0.016f);
}
}
...
That returns "An object reference is required for the non_static field...". What can I do?
Thanks.

Simplest quickest. Instead of 2 classes with 2 different number make 1 called EnemyHP. Add the component to the enemy prefabs and on the prefab in the inspector set the component's health to 4 for enemy 1 and 10 for enemy 2. Then :
void OnTriggerEnter2D(Collider2D other)
{
//you can probably just make both enemy the same tag.
if (other.tag == "Enemy" || other.tag == "Enemy2")
{
//get the Hp component of the specific enemy.
EnemyHP hpComponent = other.gameObject.GetComponent<EnemyHP>();
hpComponent.health--;
Destroy(gameObject);
if (hpComponent.health < 1)
{
Destroy(other.gameObject);
PlayerScore.playerScore++;
}
}
}

Particle System not working on multiple enemies

I have a particle system for when the enemy is destroyed. I have multiple enemies coming from the same path (using the same prefab) and the particle system is only working on the first enemy. Can someone tell me why it is not working on the others as well? Thank you.
EnemyShooting scrip (this is where the piece of code is for the explosion):
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;
public Transform explosion;
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
}
if (explosion)//EXPLOSION CODE
{
GameObject exploder = ((Transform)Instantiate(explosion, this.transform.position, this.transform.rotation)).gameObject;
Destroy(exploder, 2.0f);
}
}
}
void DestroyEnemy()
{
if(CurrentNumberOfHits >= MaxNumberOfHits)
{
Destroy(gameObject);
EnemySpawner.Instance.OnEnemyDeath(); // Tell the EnemySpawner that someone died
}
}
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();
}
}
EnemySpawner : (I thought this script might help in a way so I attached it)
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 int EnemiesToNextLevel = 7;
public int KilledEnemies = 0;
public LevelManager myLevelManager;
public static EnemySpawner Instance = null;
int timesEnemyHit;
IEnumerator SpawningEnemies()
{
while (CurrentNumOfEnemies <= MaxEnemies)
{
GameObject Enemy = Instantiate(EnemyPreFab, this.transform.position, Quaternion.identity);
CurrentNumOfEnemies++;
yield return new WaitForSeconds(EnemySpawnTime);
}
}
void Start()
{
if (Instance == null)
Instance = this;
StartCoroutine(SpawningEnemies());
timesEnemyHit = 0;
if (this.gameObject.tag == "EnemyHit")
{
CurrentNumOfEnemies++;
}
}
public void OnEnemyDeath()
{
CurrentNumOfEnemies--;
/*
if (CurrentNumOfEnemies < 5)
{
// You killed everyone, change scene:
LaserLevelManager.LoadLevel("NextLevelMenu");
}
*/
KilledEnemies++;
if (KilledEnemies >= EnemiesToNextLevel)
{
LaserLevelManager.LoadLevel("NextLevelMenu");
}
}
}

null reference exception when accessing the variable from a prefab

I get the null reference exception error when trying to change the boolean to right (or left in that regard). My prefab should spawn at FirepointL.
My script does recognise the prefeb as it does not return a Null for finding the prefab (tested this).
I made sure my boolean was set to Public and i had dropped all the GameObjects to their designated places in the Inspector.
using System.Collections;
using System.Collections.Generic;
using UnityEngine;
public class PlayerMovement : MonoBehaviour
{
public GameObject bullet;
private Rigidbody2D myRigidbody;
private float speed = 15;
private bool facingRight;
private bool ground = false;
private float jump = 23;
// Start is called before the first frame update
void Start()
{
facingRight = true;
myRigidbody = GetComponent<Rigidbody2D>();
}
// Update is called once per frame
void FixedUpdate()
{
float horizontal = Input.GetAxis("Horizontal");
bullet = GameObject.FindGameObjectWithTag("Button");
Movement(horizontal);
Flip(horizontal);
if (Input.GetKey("w"))
{
if (ground)
{
GetComponent<Rigidbody2D>().velocity = new Vector2(GetComponent<Rigidbody2D>().velocity.x, jump);
}
}
// this is the part that returns the error
if (facingRight == true)
{
bullet.GetComponent<weapon>().right = true;
}
if (facingRight == false)
{
bullet.GetComponent<weapon>().right = false;
}
}
void OnTriggerEnter2D()
{
ground = true;
}
void OnTriggerExit2D()
{
ground = false;
}
private void Movement(float horizontal)
{
myRigidbody.velocity = new Vector2(horizontal * speed,myRigidbody.velocity.y);
}
private void Flip(float horizontal)
{
if (horizontal > 0 && !facingRight || horizontal < 0 && facingRight)
{
facingRight = !facingRight;
Vector3 theScale = transform.localScale;
theScale.x *= -1;
transform.localScale = theScale;
}
}
}
using System.Collections;
using System.Collections.Generic;
using UnityEngine;
public class weapon : MonoBehaviour
{
// Start is called before the first frame update
public bool right;
public Transform firepointR;
public Transform firepointL;
public GameObject bulletPrefab;
// Update is called once per frame
void Update()
{
if (Input.GetKeyDown("space"))
{
Debug.Log("It's the space key");
Shoot();
}
}
void Shoot()
{
if (right == true)
{
Instantiate(bulletPrefab, firepointR.position, firepointR.rotation);
}
if(right == false)
{
Instantiate(bulletPrefab, firepointL.position, firepointL.rotation);
}
}
}
using System.Collections;
using System.Collections.Generic;
using UnityEngine;
public class bullet : MonoBehaviour
{
public float speed = 20;
public Rigidbody2D rb;
// Start is called before the first frame update
void Start()
{
rb.velocity = transform.right * speed;
}
// Update is called once per frame
void Update()
{
}
}

Not sure if it's the exact issue, but there's a problem in PlayerMovement class. When you retrieve bullet you assume that an object with Button tag is present.
In my opinion, you should check for it with
// this is the part that returns the error
if (bullet && facingRight == true)
{
bullet.GetComponent<weapon>().right = true;
}
if (bullet && facingRight == false)
{
bullet.GetComponent<weapon>().right = false;
}

I think there is a problem with naming conventions. You are trying to find out a bullet whose name is "Button" but when you are instantiating the gameobject, it names it to something like Button(clone).
One solution that comes in my mind:
1st step:
Make a public static variable inside PlayerMovement script.
public static PlayerMovement Instance;
private void Awake()
{
Instance = this;
}
Set its value inside the awake function so that you can call it from anywhere.
2nd step:
I modified the shoot function.
void Shoot()
{
GameObject _firePosition = right == true ? firepointR : firepointL;
PlayerMovement.Instance.bullet = Instantiate(bulletPrefab, _firePosition.position, _firePosition.rotation); // we are setting the reference on runtime whenever we spawn a new bullet.
}
3rd Step:
Remove this line from PlayerMovement script as it is not needed now.
bullet = GameObject.FindGameObjectWithTag("Button");
PS: Code will not work if you don't follow step 3. Let me know if it helps. :)

Cause player to take damage in Unity 2D

I made two scripts. One that'll keep track of the player's health, health bar and cause the screen to flash when the player is damaged. The other script is meant to be placed on any object I wish to do damage to the player, on contact. My problem is, Nothing seems to be doing any damage to the player.
PlayerHealth.cs:
using UnityEngine;
using UnityEngine.UI;
public class PlayerHealth : MonoBehaviour
{
public int currentHealth;
public float flashSpeed = 5;
public Slider healthSlider;
public Color flashColour = new Color(1, 0, 0, 0.1f);
bool isDead;
bool damaged;
private void Awake()
{
currentHealth = 100;
}
private void Update()
{
damaged = false;
}
public void TakeDamage(int amount)
{
damaged = true;
currentHealth -= amount;
healthSlider.value = currentHealth;
}
}
AttackPlayer.cs:
using UnityEngine;
public class AttackPlayer : MonoBehaviour
{
public float timeBetweenAttacks = 0.5f;
public int attackDamage = 10;
GameObject player;
PlayerHealth playerHealth;
float timer;
private void Awake()
{
player = GameObject.FindGameObjectWithTag("Player");
playerHealth = player.GetComponent<PlayerHealth>();
}
private void OnTriggerEnter2D(Collider2D col)
{
if (col.gameObject == player)
{
Attack();
}
}
private void Update()
{
timer += Time.deltaTime;
if(playerHealth.currentHealth <=0)
{
// TODO: add death script here.
}
}
void Attack()
{
timer = 0f;
if(playerHealth.currentHealth > 0)
{
playerHealth.TakeDamage(attackDamage);
}
}
}
The player has a rigidbody2D. The player and damaging objects have Box Collider 2D's on them.

Make sure that the players Collider has isTrigger enabled.
attackDamage is public -> set in the inspector. Make sure it is not 0.
You could use
[Range(1,100)] public int attackDamage = 10;
to automatically clamp the value in the inspector.
A guess but I'ld say your Collider might not be on the GameObject player but probably on one of its children => the condition col.gameObject == player is not true.
Instead of GameObject references rather compare the PlayerHealth (since there is only one) reference like
private void OnTriggerEnter2D(Collider2D col)
{
// gets PlayerHealth component on this or any parent object
var health = col.GetComponentInParent<PlayerHealth>();
if (health == playerHealth)
{
Attack();
}
}
You have
private void Update()
{
damaged = false;
}
public void TakeDamage(int amount)
{
damaged = true;
currentHealth -= amount;
healthSlider.value = currentHealth;
}
I don't know what else should happen on TakeDamage but the value of damaged is resetted in Update so right after it was set by the Trigger because Physics events like OnTriggerEnter are executed before Update (see execution Order).
Hint: Instead of
player = GameObject.FindGameObjectWithTag("Player");
playerHealth = player.GetComponent<PlayerHealth>();
you could also use
playerHealth = FindObjectOfType<PlayerHealth>();
if that component exists only once in your scene.
Or to be more flexible (having multiple Players) all you have to do is change your OnTriggerEnter2D and Attack method to
private void OnTriggerEnter2D(Collider2D col)
{
// gets PlayerHealth component on this or any parent object
var health = col.GetComponentInParent<PlayerHealth>();
if (health != null)
{
Attack(health);
}
}
void Attack(PlayerHealth health)
{
timer = 0f;
if(health.currentHealth > 0)
{
health.TakeDamage(attackDamage);
}
}
So you wouldn't need to get the reference before.