# contacts

> The contact points generated by the physics engine. You should avoid using this as it produces memory garbage. Use Collision.GetContact or Collision.GetContacts instead.

## Definition

* **Type:** Property
* **Namespace:** [UnityEngine](/engine/6000.7/script-reference/unityengine.md)
* **Assembly:** UnityEngine.PhysicsModule

```csharp
public ContactPoint[] contacts { get; }
```

### Remarks

Every contact contains a contact point, normal and the two colliders that collided (see [ContactPoint](/engine/6000.7/script-reference/unityengine/contactpoint.md)). From inside MonoBehaviour.OnCollisionStay(Collision) or MonoBehaviour.OnCollisionEnter(Collision) you can always be sure that `contacts` has at least one element.

### Examples

```csharp
using UnityEngine;

public class ExampleScript : MonoBehaviour
{
    void OnCollisionStay(Collision collision)
    {
        foreach (ContactPoint contact in collision.contacts)
        {
            print(contact.thisCollider.name + " hit " + contact.otherCollider.name);
            // Visualize the contact point
            Debug.DrawRay(contact.point, contact.normal, Color.white);
        }
    }
}
```

```csharp
 // A grenade
 // - instantiates an 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);
    }
}
```