title: Disable or enable collisions based on object tag Unity 2d
body: <p>I want to disable or enable collision with object in unity 2d game based on its tag. Lets say I have object with tag "foo1" and objects with tag "foo2". If user choose to collide with objects "foo1" then it should not collide with objects "foo2".</p>
  
  <p>How could I achieve this? I tried this:</p>
  
  <pre><code> void OnCollisionEnter(Object other)
   {
        if (other.tag == "foo1")
            collider.enabled = false;
   }
  </code></pre>
  
  <p>But this is not working for two reasons. First object has to have isTrigger set to true (this could not be set for objects that serves as ground) and if I disable entire collider then object will fall through ground. </p>
  
  <p>I am new to unity and I will study it in more details but I am asking for quick help and maybe idea how to do this?</p>