Repository/Assets/arTap.cs

using System.Collections;
using System.Collections.Generic;
using UnityEngine;
using UnityEngine.XR.ARFoundation;
using UnityEngine.XR;
using UnityEngine.XR.ARSubsystems;
using System;

public class arTap : MonoBehaviour
{
    public GameObject objectToPlace;
    public GameObject placementIndicator;
    private Camera myCamera;
    private ARSessionOrigin arOrigin;
    private ARRaycastManager raycastManager;
    private Pose placementPose;
    private bool placementPoseIsValid = false;

    void Start()
    {
        arOrigin = FindObjectOfType<ARSessionOrigin>();
        raycastManager = FindObjectOfType<ARRaycastManager>();

    }

    void Update()
    {
        UpdatePlacementPose();
        UpdatePlacementIndicator();
        Debug.Log(placementPoseIsValid);

        if (placementPoseIsValid && Input.touchCount > 0 && Input.GetTouch(0).phase == TouchPhase.Began)
        {
            PlaceObject();
        }
    }

    private void PlaceObject()
    {
        Instantiate(objectToPlace, placementPose.position, placementPose.rotation);
    }

    private void UpdatePlacementIndicator()
    {
        if (placementPoseIsValid)
        {
            placementIndicator.SetActive(true);
            placementIndicator.transform.SetPositionAndRotation(placementPose.position, placementPose.rotation);
        }
        else
        {
            placementIndicator.SetActive(false);
        }
    }

    private void UpdatePlacementPose()
    {
        var screenCenter = Camera.main.ViewportToScreenPoint(new Vector3(0.5f, 0.5f));
        var hits = new List<ARRaycastHit>();
        raycastManager.Raycast(screenCenter, hits, TrackableType.Planes);
        Debug.Log(hits);

        placementPoseIsValid = hits.Count > 0;
        if (placementPoseIsValid)
        {
            placementPose = hits[0].pose;

            var cameraForward = Camera.main.transform.forward;
            var cameraBearing = new Vector3(cameraForward.x, 0, cameraForward.z).normalized;
            placementPose.rotation = Quaternion.LookRotation(cameraBearing);
        }
    }

}