OnCollisionEnter is called when this collider/rigidbody has begun touching another rigidbody/collider.
In contrast to OnTriggerEnter, OnCollisionEnter is passed the Collision class and not a Collider. The Collision class contains information about contact points, impact velocity etc. If you don't use collisionInfo in the function, leave out the collisionInfo parameter as this avoids unneccessary calculations. Notes: Collision events are only sent if one of the colliders also has a non-kinematic rigidbody attached. Collision events will be sent to disabled MonoBehaviours, to allow enabling Behaviours in response to collisions.
using UnityEngine; using System.Collections;
public class ExampleClass : MonoBehaviour { AudioSource audioSource;
void Start() { audioSource = GetComponent<AudioSource>(); }
void OnCollisionEnter(Collision collision) { // Debug-draw all contact points and normals foreach (ContactPoint contact in collision.contacts) { Debug.DrawRay(contact.point, contact.normal, Color.white); }
// Play a sound if the colliding objects had a big impact. if (collision.relativeVelocity.magnitude > 2) audioSource.Play(); } }
Another example:
// A grenade // instantiates a explosion prefab when hitting a surface // then destroys itself using UnityEngine; using System.Collections;
public class ExampleClass : MonoBehaviour { public Transform explosionPrefab; void OnCollisionEnter(Collision collision) { ContactPoint contact = collision.contacts[0];
// Rotate the object so that the y-axis faces along the normal of the surface Quaternion rot = Quaternion.FromToRotation(Vector3.up, contact.normal); Vector3 pos = contact.point; Instantiate(explosionPrefab, pos, rot); Destroy(gameObject); } }