How can I detect if a gameObject has collided with two other specific objects at the same time?

Question

How can I detect if a gameObject has collided with two other specific objects at the same time?

This is what I intend to do but it does not work:

void OnCollisionEnter (Collision col)
{

if(col.gameObject.name == "object1" && "object2")
    {
        Destroy(gameObject);
    }
}

How can I correct this piece of code?

Answer 1

If you are colliding with 2 objects the method OnCollisionEnter will be called twice, so you must keep track of their gameobject or names.

List<string> contacts = new List<string>();
void OnCollisionEnter (Collision col)
{
    contacts.Add(col.gameObject.name);
    if(contacts.Contains("object1") && contacts.Contains("object2"))
    {
        Destroy(gameObject);
    }
}
void OnCollisionExit(Collision col)
{
    contacts.Remove(col.gameObject.name);
}

but remember to add the reference to get the lists to work

using System.Collections.Generics;

Answer 2

IF you are checking collisions on any of the events fired regarding collison, like Collider.OnCollisionEnter Collider.OnCollisionStay Collider.OnCollisionExit , you could get ALL the Contact points from the Collision parameter passed by the event by

Collision.contacts and you could get the gameObject by Enumerating the ContactPoint s in Collision.contacts and this : ContactPoint.otherCollider.gameObject and check its name :)

Hope it helped :)

More info : Collision Contacts - Unity Docs