How to ignore collision by tag?

Unity Engine
1

How can i get something to ignore a collision if its tag is player?
I couldn’t find anything with google, this is what i have. I know the first part is wrong because it gives me errors.

Here is what i have so far.

function OnCollisionEnter(collision : Collision) {
   if (collision.gameObject.tag == "Player") {
      
      Destroy (collision.gameObject.GetComponent (Rigidbody));
      Destroy (collision.gameObject.GetComponent (RotateKnife));
      SendMessageUpwards("ApplyDamage", damage, SendMessageOptions.DontRequireReceiver);
   }
}
2

add a layermask tag, and go to physics, there ignore collision between two layermask

3

You can’t ignore collisions based on tags, only with layers. You can use tags to do things after a collision has occurred, but at that point it is, by definition, too late to ignore the collision.

–Eric

4

You could attach a script to a trigger Collider (hotspot) and create an event to only occur on Enter or Exit, or OnCollide and limit it by the tag of the item. However you would want to have a corresponding script on another object to enact the collide event.

I have seen this done in a game called “Ratspell” where the collision event occurs 100% by script to stop the character. This is basically what you’d want to do for path-finding and so on.