Bullets instantiate inside wall, doesn't trigger OnCollisionEnter2D

Question

void OnCollisionEnter2D(Collision2D col)
    {
        if (col.gameObject.tag == "Wall")
        {
            Destroy(gameObject);
        }
    }

I use this script. All is ok, but if my bullet spawns in Wall, it doesn't react with wall. It flies inside the wall. So, what should I use for instan destroy bullet if it spawns inside wall?

Bullet spawn method:

Instantiate(bullet1, firepoint1.position, firepoint1.rotation);

Answer 1

Since colliders are giving troubles when the GameObject is instantiated inside the other collider. I recommed you to first check if the bullet would be instantiated inside the Wall, and in that case, directly don´t instantiate it. I believe this will make the code more efficient.

So first you need to add the Wall in a Layer (Here you can see how to create a new layer and assign the wall to that layer). An pass it as parameter to the script you use to instantiate the bullets (the script of the tank for example).

public LayerMask wallLayer;

You save the transform of the tank in a variable

// Variable with position of the Tank
Transform _transform;

void Awake () {

    _transform = GetComponent<Transform> ();

}

Next thing you generate Physics2D.Linecast. Source. Assuming you use a script attached to the tank GameObject to fire the bullets:

// Linecase goes from the tank position to the place where you would be instantiating the bullet
boolean insideWall = Physics2D.Linecast(_transform.position, firepoint1.position, wallLayer);

Then you instantiate the bullet only in case you would not instantiate it inside the wall.

if(!insideWall)
    Instantiate(bullet1, firepoint1.position, firepoint1.rotation);