How to place a prefab and then remove it via voice when looked at

Question

User can place objects (prefabs) at runtime using hands/gaze. Voice command ""Remove" should remove the current focussed (looked at) object.

I tried instantiating the objects and adding the Intractable script. But I am stuck add adding OnfocusEnter and OnfocusExit events at runtime.

Hooking up the events on the prefab wont work as the references are in the scene.

Answer 1

Based on @jShull answer I came up with a simple solution for what I needed. Since there is no global listener for focus events I basically made my own.

I also added an earlier discussion (before I posted the question here) with two Microsoft Developers of the Mixed Reality Toolkit which could help out of you are looking for more functionality: https://github.com/microsoft/MixedRealityToolkit-Unity/issues/4456

"Object" script that is a component of the object that needs to be removed or interacted with.

using Microsoft.MixedReality.Toolkit.Input;
using UnityEngine;

public class Object: MonoBehaviour, IMixedRealityFocusHandler
{
    public GameManager _gameManager;

    public void OnFocusEnter(FocusEventData eventData)
    {
        Debug.Log("Focus ON: " + gameObject);
        _gameManager.SetFocussedObject(gameObject);
    }

    public void OnFocusExit(FocusEventData eventData)
    {
        Debug.Log("Focus OFF: " + gameObject);
        _gameManager.ResetFocussedObject();
    }
}

"GameManager" script functions that sets the focussedObject

public void SetFocussedObject(GameObject object)
{
    focussedObject = object;
}

public void ResetFocussedObject()
{
    focussedObject = null;
}

Remove Object function is connect to the "Remove" global speech command in the "Speech Input Handler" component. It just removes the "focussedObject" inside the GameManager.