ITriggerCallback

Description

An interface that when implemented, can be called as a target by PhysicsWorld.SendTriggerCallbacks.

A trigger shape doesn't collide with other shapes. Other shapes pass through it instead. Unity calls OnTriggerBegin2D and OnTriggerEnd2D on the main thread after the simulation finishes. For a worked example, refer to the PhysicsShapeTriggerCallback example in the Physics Core 2D examples repository

Additional resources: PhysicsWorld.SendTriggerCallbacks, IContactCallback

 using UnityEngine;
 using Unity.U2D.Physics;

 // Add the PhysicsCallbacks.ITriggerCallback interface.
 public class DetectTriggerOverlap : MonoBehaviour, PhysicsCallbacks.ITriggerCallback
 {
     void Start()
     {
         PhysicsWorld world = PhysicsWorld.defaultWorld;

         // Create a trigger shape that reports overlaps instead of colliding.
         PhysicsBody triggerBody = world.CreateBody(new PhysicsBodyDefinition
         {
             position = new Vector2(0.5f, 8f),
             type = PhysicsBody.BodyType.Dynamic
         });
         PhysicsShape triggerShape = triggerBody.CreateShape(CircleGeometry.defaultGeometry, new PhysicsShapeDefinition
         {
             isTrigger = true,
             triggerEvents = true
         });
         triggerShape.callbackTarget = this;

         // Create a static shape for the trigger to overlap.
         PhysicsBody staticBody = world.CreateBody(new PhysicsBodyDefinition
         {
             position = new Vector2(0f, 0f),
             type = PhysicsBody.BodyType.Static
         });
         staticBody.CreateShape(new CircleGeometry { radius = 3f }, new PhysicsShapeDefinition { triggerEvents = true });
     }

     // Log when the trigger starts overlapping another shape.
     public void OnTriggerBegin2D(PhysicsEvents.TriggerBeginEvent beginEvent)
     {
         Debug.Log("Trigger overlap started.");
     }

     // Log when the trigger stops overlapping another shape.
     public void OnTriggerEnd2D(PhysicsEvents.TriggerEndEvent endEvent)
     {
         Debug.Log("Trigger overlap ended.");
     }
 }

Public Methods