The contact points generated by the physics engine.
Every contact contains a contact point, normal and the two colliders that collided (see ContactPoint).
From inside OnCollisionStay or OnCollisionEnter you can
always be sure that contacts
has at least one element.
no example available in C#
// 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]; Quaternion rot = Quaternion.FromToRotation(Vector3.up, contact.normal); Vector3 pos = contact.point; Instantiate(explosionPrefab, pos, rot); Destroy(gameObject); } }