Thank you for helping us improve the quality of Unity Documentation. Although we cannot accept all submissions, we do read each suggested change from our users and will make updates where applicable.
CloseFor some reason your suggested change could not be submitted. Please <a>try again</a> in a few minutes. And thank you for taking the time to help us improve the quality of Unity Documentation.
Closeother | The other Collider2D involved in this collision. |
Sent when another object enters a trigger collider attached to this object (2D physics only).
Further information about the other collider is reported in the Collider2D parameter passed during the call.
Trigger events will be sent to disabled MonoBehaviours, to allow enabling Behaviours in response to collisions.
See Also: The Collider2D class and the OnTriggerExit2D and OnTriggerStay2D messages.
An OnTriggerEnter2D example is shown. This example has two empty GameObjects, called GameObject1
and GameObject2
. These both have script files which makes the example work. The first script, Example1
, creates a Sprite and adds a BoxCollider2D and a Rigidbody2D. This object falls under gravity and collides with Example2
. Example2
has no visibility. (The rectangle it creates is visible in the Scene window.) Both GameObjects report the collision.
The script below is Example1.
using System.Collections; using System.Collections.Generic; using UnityEngine;
// Create GameObject1 that falls under gravity. It will pass through // Example2 and cause a collision. GameObject1 is moved back to // the start position and it will again start to fall under gravity.
public class Example1 : MonoBehaviour { void Awake() { SpriteRenderer sr; sr = gameObject.AddComponent<SpriteRenderer>() as SpriteRenderer; sr.color = new Color(0.9f, 0.9f, 0.1f, 1.0f);
BoxCollider2D bc; bc = gameObject.AddComponent<BoxCollider2D>() as BoxCollider2D; bc.size = new Vector2(1.0f, 1.0f);
Rigidbody2D rb; rb = gameObject.AddComponent<Rigidbody2D>() as Rigidbody2D; rb.gravityScale = 1.0f;
// A square in the Resources folder is used. gameObject.GetComponent<SpriteRenderer>().sprite = Resources.Load<Sprite>("square");
// GameObject1 starts 3 units in the Up direction. gameObject.transform.position = new Vector3(0.0f, 3.0f, 0.0f); gameObject.transform.localScale = new Vector3(0.5f, 0.5f, 1.0f); }
private float timer = 0.0f; private bool restart = false;
void FixedUpdate() { if (restart == true) { timer = timer + Time.deltaTime; if (timer > 0.25f) { gameObject.transform.position = new Vector3(0.0f, 3.0f, 0.0f); gameObject.GetComponent<Rigidbody2D>().velocity = new Vector2(0.0f, 0.0f); restart = false; } } }
// called when this GameObject collides with GameObject2. void OnTriggerEnter2D(Collider2D col) { Debug.Log("GameObject1 collided with " + col.name); restart = true; timer = 0.0f; } }
This is Example2
which is the collide script for the second GameObject:
using System.Collections; using System.Collections.Generic; using UnityEngine;
// Create a rectangle that the other GameObject will collide with. // Note that this GameObject has no visibility. // (View in the Scene view to see this GameObject.)
public class Example2 : MonoBehaviour { void Awake() { BoxCollider2D bc; bc = gameObject.AddComponent<BoxCollider2D>() as BoxCollider2D; bc.size = new Vector2(3.0f, 1.0f); bc.isTrigger = true;
gameObject.transform.localScale = new Vector3(3.0f, 1.0f, 1.0f); gameObject.transform.position = new Vector3(0.0f, -2.0f, 0.0f); }
void OnTriggerEnter2D(Collider2D col) { Debug.Log("GameObject2 collided with " + col.name); } }
Did you find this page useful? Please give it a rating:
Thanks for rating this page!
What kind of problem would you like to report?
Thanks for letting us know! This page has been marked for review based on your feedback.
If you have time, you can provide more information to help us fix the problem faster.
Provide more information
You've told us this page needs code samples. If you'd like to help us further, you could provide a code sample, or tell us about what kind of code sample you'd like to see:
You've told us there are code samples on this page which don't work. If you know how to fix it, or have something better we could use instead, please let us know:
You've told us there is information missing from this page. Please tell us more about what's missing:
You've told us there is incorrect information on this page. If you know what we should change to make it correct, please tell us:
You've told us this page has unclear or confusing information. Please tell us more about what you found unclear or confusing, or let us know how we could make it clearer:
You've told us there is a spelling or grammar error on this page. Please tell us what's wrong:
You've told us this page has a problem. Please tell us more about what's wrong:
Thanks for helping to make the Unity documentation better!