C# | Find Object by Type | Examinable | ExaminableManager | ExamineTarget | AR Selection Interactable | Interaction Events | OnSelection()

Unity AR : Programming Custom Mechanics | Examination Mode

Create a Mechanic to Allow the User to Examine Objects Upon Selection

STEPS NEEDED

1. Create & Configure ExamineTarget GameObject
2. Create & Configure ExaminableManager GameObject & Script
3. Create & Configure Examinable Script
4. Configure SelectEntered() Logic

STEP ONE — Create & Configure ExamineTarget GameObject

XR Origin > Camera Offset > Main Camera > Create Empty gameObject

ExamineTarget is used as a placeholder for the desired position of the examinable object in examine mode. It also will become the parent of the examinable object, thus attaching it to a fixed position on the screen.

ExamineTarget’s position will need to be offset on the Y axis to be a short distance away from the camera.

STEP TWO — Create & Configure ExaminableManager GameObject & Script

Scene > Create Empty GameObject → ExaminableManager
Project > Scripts > Create New Script → ExaminableManager
ExaminableManager > Add Component > ExaminableManager

ExaminableManager is a manager class to handle all logic related to the examine mechanic.

public class ExaminableManager : MonoBehaviour
{
    [SerializeField] 
    private Transform _examineTarget;

    public void PerformExamine(Examinable examinable)
    {
        examinable.transform.position = _examineTarget.position;
        examinable.transform.parent = _examineTarget;

        print("Examine has been performed");
    }
}

_examineTarget — examineTarget GameObject : gains vital data from the examineTarget such as its position, and the ability to assign child objects to it.

STEP THREE — Create & Configure Examinable Script

Project > Scripts > Create New Script → Examinable
ExaminationCube_PlacementPrefab > Add Component > Examinable

Examinable Component is used to allow the PlacementPrefab to communicate with the ExaminableManager.

public class Examinable : MonoBehaviour
{
    [SerializeField]
    private ExaminableManager _examinableManager;

    private void Start()
    {
        _examinableManager = FindAnyObjectByType<ExaminableManager>();
    }

    public void RequestExamine()
    {
        _examinableManager.PerformExamine(this);

        print("Examine has been requested");
    }
}

_examinableManager → used to reference the ExaminableManager GameObject. Since this component will be on a prefab that will not be in the scene right away, we need to use the FindAnyObjectByType<>() to auto reference the ExaminableManager once the prefab enters the scene.

STEP FOUR — Configure SelectEntered() Logic

ExaminationCube_PlacementPrefab > AR Selection Interactable

SelectEntered() Interactable Events : Examinable.RequestExamine() → performs the process to enter the placementPrefab into examination mode.

TEST