Example scripts for collider events

The following examples demonstrate ways to call events from collisionA collision occurs when the physics engine detects that the colliders of two GameObjects make contact or overlap, when at least one has a Rigidbody component and is in motion. More info
See in Glossary functions. They use OnCollisionEnter and OnTriggerEnter respectively, but the concepts apply to all OnCollision and OnTrigger functions.

Example: Different events for different GameObject properties

You can configure your scriptsA piece of code that allows you to create your own Components, trigger game events, modify Component properties over time and respond to user input in any way you like. More info
See in Glossary to trigger different events based on the properties of the other colliderAn invisible shape that is used to handle physical collisions for an object. A collider doesn’t need to be exactly the same shape as the object’s mesh - a rough approximation is often more efficient and indistinguishable in gameplay. More info
See in Glossary’s associated GameObjectThe fundamental object in Unity scenes, which can represent characters, props, scenery, cameras, waypoints, and more. A GameObject’s functionality is defined by the Components attached to it. More info
See in Glossary, such as its name or tag. This is useful if, for example, you want to allow some colliders to produce an event, but not others.

The following example prints a different message depending on whether the other collider that has touched this collider has a tag of “Player” or “Enemy”.

using UnityEngine;
using System.Collections;

public class DoorObject : Monobehaviour
{
    private void OnCollisionEnter(Collider other)
    {
        if (other.CompareTag("Player"))
        {
            Debug.Log ("The player character has touched the door.")
        }

        if (other.CompareTag("Enemy"))
        {
            Debug.Log ("An enemy character has touched the door!")
        }
    }
}

Example: Send an event message every physics update

The following example uses a trigger collider to produce a hoverpad. The trigger collider is positioned directly on top of a hoverpad GameObject, and applies a constant upward force to any GameObject within its trigger.

using UnityEngine;
using System.Collections;

public class HoverPad : MonoBehaviour
{
    // define a value for the upward force calculation
    public float hoverForce = 12f;

    // whenever another collider is in contact with this trigger collider…
    void OnTriggerStay (Collider other)
    {
        // …add an upward force to the Rigidbody of the other collider.
        other.rigidbody.AddForce(Vector3.up * hoverForce, ForceMode.Acceleration) 
    }
}