Collision between objects

Collisions are detected between CharacterControllers and colliders, or Rigidbodies and colliders. Objects that don't have one of these components don't register collisions well enough (an object with a collider may cause OnCollision events only when hitting a rigidbody that's moving - a still rigidbody enters sleep mode, and ignores simple colliders).

If you add a CharacterController to the object (it's a capsule collider, thus doesn't fit well in many objects), use OnControllerColliderHit to process collisions:

 function OnControllerColliderHit(hit: ControllerColliderHit){
     if (hit.rigidbody){
          print("Hit a rigidbody!");
     }
 }

You must move a CharacterController with Move or SimpleMove, or collisions won't be detected.

If you add a Rigidbody to the object, use OnCollisionEnter to verify collisions:

 OnCollisionEnter(col: Collision){
     if (col.rigidbody){
          print("Hit another rigidbody!");
     }
 }

Rigidbodies may have colliders of any shape, but you should move them with AddForce or by setting rigidbody.velocity directly in order to have reliable collision detection.

Ok. Thank you!