Rasagar/Library/PackageCache/com.unity.visualeffectgraph/Documentation~/OutputEventHandlers.md

Output Event Handlers

A VFXOutputEventAbstractHandler is an API helper that hooks into an Output Event to allow you to execute scripts based on the event.

The Visual Effect Graph includes a set of example scripts as a sample. For information on how to install the sample, see Installing sample scripts.

Output Event Handler API

To create your own output event handler, write a script that extends the UnityEngine.VFX.Utility.VFXOutputEventAbstractHandler class.

When you write a MonoBehaviour that extends this class, it reduces the amount of code required to perform a hook. This is because the base class does the job of filtering the event and calls the following method :

override void OnVFXOutputEvent(VFXEventAttribute eventAttribute)

When you implement this method, Unity calls it every time the event triggers and passes in the event's attributes.

Example

The following example teleports a Game Object to the Given position when it receives an event.

[RequireComponent(typeof(VisualEffect))]
public class VFXOutputEventTeleportObject : VFXOutputEventAbstractHandler
{
    public Transform target;

    static readonly int kPosition = Shader.PropertyToID("position");

    public override void OnVFXOutputEvent(VFXEventAttribute eventAttribute)
    {
        if(target != null)
            target.position = eventAttribute.GetVector3(kPosition);
    }
}

Using Output Event Helpers

To help you create your own VFXOutputEventAbstractHandler, the Visual Effect Graph package includes a set of example scripts that you can install via the Package Manager. For information on how to use these example scripts, see Sample content.