Unity - Disable AR HitTest after initial placement - ios

Question

I am using ARKit plugin for Unity leveraging the UnityARHitTestExample.cs.
After I place my object into the world scene I want to disable the ARKit from trying to place the object again every time I touch the screen. Can someone please help?

Answer 1

There are a number of ways you can achieve this, although perhaps the simplest is creating a boolean to determine whether or not your model has been placed.
First off all you would create a boolean as noted above e.g:
private bool modelPlaced = false;
Then you would set this to true within the HitTestResultType function once your model has been placed:
bool HitTestWithResultType (ARPoint point, ARHitTestResultType resultTypes)
{
List<ARHitTestResult> hitResults = UnityARSessionNativeInterface.GetARSessionNativeInterface ().HitTest (point, resultTypes);
if (hitResults.Count > 0) {
foreach (var hitResult in hitResults) {
//1. If Our Model Hasnt Been Placed Then Set Its Transform From The HitTest WorldTransform
if (!modelPlaced){
m_HitTransform.position = UnityARMatrixOps.GetPosition (hitResult.worldTransform);
m_HitTransform.rotation = UnityARMatrixOps.GetRotation (hitResult.worldTransform);
Debug.Log (string.Format ("x:{0:0.######} y:{1:0.######} z:{2:0.######}", m_HitTransform.position.x, m_HitTransform.position.y, m_HitTransform.position.z));
//2. Prevent Our Model From Being Positioned Again
modelPlaced = true;
}
return true;
}
}
return false;
}
And then in the Update() function:
void Update () {
//Only Run The HitTest If We Havent Placed Our Model
if (!modelPlaced){
if (Input.touchCount > 0 && m_HitTransform != null)
{
var touch = Input.GetTouch(0);
if (touch.phase == TouchPhase.Began || touch.phase == TouchPhase.Moved)
{
var screenPosition = Camera.main.ScreenToViewportPoint(touch.position);
ARPoint point = new ARPoint {
x = screenPosition.x,
y = screenPosition.y
};
ARHitTestResultType[] resultTypes = {
ARHitTestResultType.ARHitTestResultTypeExistingPlaneUsingExtent,
};
foreach (ARHitTestResultType resultType in resultTypes)
{
if (HitTestWithResultType (point, resultType))
{
return;
}
}
}
}
}
}
Hope it helps...