2D collider problems

Questions & Answers
1

Hello,
I have got a problem with 2D collididers. I don’t know why but Unity doesn’t detect colliders. I am working on 2d game and i am trying to do the attack by player by throwing a spear and I want it to deal damage to enemy what it is in collision with it. Here is the code:

{
public float playerSpeed = 4f;
public float playerPosX = 0;
public float playerPosY = 0;
public float swordRotateSpeed = 0.5f;
private bool attack = false;

public GameObject player;
public GameObject kopija;

void Start()
{

}

void FixedUpdate()
{
        Vector2 targetVelocity = new Vector2(Input.GetAxisRaw("Horizontal"), Input.GetAxisRaw("Vertical"));
        GetComponent<Rigidbody2D>().velocity = targetVelocity * playerSpeed;
    }

// Update is called once per frame
void Update()
{
    StartCoroutine(PlayerSavePos());
    if(Input.GetKey(KeyCode.Mouse0))
   {
        attack = true;
    }

    if (attack==true)
    {
        //sword.transform.Rotate(Vector2.right, swordRotateSpeed * Time.deltaTime);
        kopija.transform.Translate(Vector2.up * Time.deltaTime);
    }

}
IEnumerator PlayerSavePos()
{
    yield return new WaitForSeconds(5.0f);
    playerPosX = player.transform.position.x;
    PlayerPrefs.SetFloat("PlayerX", playerPosX);
    PlayerPrefs.Save();
    playerPosY = player.transform.position.y;
    PlayerPrefs.SetFloat("PlayerY", playerPosY);
    PlayerPrefs.Save();
}
void Awake()
{
    if (PlayerPrefs.HasKey("PlayerX"))
    {
        playerPosX = PlayerPrefs.GetFloat("PlayerX");
    }
    if (PlayerPrefs.HasKey("PlayerY"))
    {
        playerPosY = PlayerPrefs.GetFloat("PlayerY");
    }

}

I tried different types of colliders and i tried to play a little bit with a Rigidbody 2d settings and nothing is working. I am using Unity 2018.2.10f1. Please if anyone could help, then help me.

2

A list of basic things to check:

If you want collision to register through script:

  • You need an OnCollisionEnter2D (if a collider isn’t set to trigger) or OnTriggerEnter2D (if the collider is set to trigger) function in a script attached to the object that has the collider

In any case:

  • You need some kind of 2D collider on both objects, not set to trigger on either of them
  • You need a dynamic rigidbody2D on (at least) one object

Another thing that I noticed that is quite possibly an issue is that you are translating kopija (is that the weapon?) rather than moving it with a rigidbody. Depending on the scale, it might be teleporting through the enemy collider, rather than actually hitting it.

It might work better for you to use a Raycast in the direction of the spear, to check if the enemy would get hit.
For example (note, I haven’t tested this):

private static void CheckIfSpearHit (Vector2 direction) { //pass in direction of the attack
     int range = 5; //or however far the weapon can reach
     RaycastHit2D hit = Physics2D.Raycast(transform.position, direction, range);

     //check if the raycast hit something
     if (hit.collider.gameObject.name == "monster") { //or whatever its name would be
          //do whatever you want here. maybe access script attached to enemy to decrease health
     }
}