How do I ignore collision between two instantiated objects.

Okay, I know there are a lot of variations of this question already out there, but none of them helps me and searching through every single one for the one right answer would take forever.

I have certain questions regarding Physics.IgnoreCollision

  1. How do I use Physics.IgnoreCollision?

From my understanding I have to use the names of two gameobjects, but this is clearly wrong since I wouldn’t be asking otherwise.

  1. How do I get transform values from instantiated objects?

I often find that I have several clones of an object which is not in the scene, but I have no idea how to get their transform values. If I try to get the transform of the original it often returns nothing.

  1. In the Physics.IgnoreCollision reference it says

Transform bullet = Instantiate(bulletPrefab) as Transform;

What exactly is happening here?

  1. You need to pass two colliders to IgnoreCollision - you would get those colliders from the GameObjects/Transforms or whatever you have to reference them.

  2. When you instantiate an object from a prefab you get a return value which is the new object, as whatever type your prefab holder was. So if you hold prefabs in GameObject variables you would do this:

    var newGo = Instantiate(someGameObjectPrefab) as GameObject;  //c#
    var newGo : GameObject = Instantiate(someGameObjectPrefab); //JS
    

And if you want the transform you get it like this:

   newGo.transform

You would get the collider for newGo by using newGo.collider

  1. It is creating a new bullet, the prefab for it is held in bulletPrefab which is a Transform variable.