MonoBehaviour.OnCollisionEnter Manual     Reference     Scripting  
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function OnCollisionEnter (collisionInfo : Collision) : void


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. Note that collision events are only sent if one of the colliders also has a non-kinematic rigid body attached.

function OnCollisionEnter(collision : Collision) {
// Debug-draw all contact points and normals
for (var contact : ContactPoint in collision.contacts) {
Debug.DrawRay(contact.point, contact.normal, Color.white);

// Play a sound if the coliding objects had a big impact.
if (collision.relativeVelocity.magnitude > 2)

OnCollisionEnter can be a co-routine, simply use the yield statement in the function.