public void OnCollisionExit(Collision collision)

Collision

receives an instance of the Collision class as the paramter. This parameter contains information about the collision such as contact points and impact velocity. If you don't use this collision data in your callback, leave out the parameter from the method declaration to avoid unneccessary calculations. Note: Collision events are only sent if one of the colliders also has a non-kinematic rigidbody attached. Collision events are sent to disabled MonoBehaviours, to allow enabling Behaviours in response to collisions. If one of the objects involved in the collision is destroyed before they separate, is not called. If your logic depends on being called whenever contact ends, including when an object is destroyed, you need to implement additional logic, such as handling cleanup in MonoBehaviour.OnDestroy() or tracking destroyed objects manually. can be a coroutine.

using UnityEngine;using System.Collections;public class Example : MonoBehaviour{    void OnCollisionExit(Collision other)    {        print("No longer in contact with " + other.transform.name);    }}