How to fix "gravity issue in unity AR project" - unity3d

Question

Project: Augmented game (vuforia)
I have a plane over which a ball resides.
The plane has rigid body and mesh collider on it.
The ball has a sphere collider and rigid body on it with gravity turned on.
As i play the game,the ball falls through the plane and keeps on falling.
I want the ball to stay on the plane so that i can control it with touch input.

Answer 1

I had this problem and I solved using the I TrackableEventHandler.
Look at this script:
using System.Collections;
using UnityEngine;
using Vuforia;
public class MarkerController: MonoBehaviour, ITrackableEventHandler
{
private TrackableBehaviour mTrackableBehavior;
// Start is called before the first frame update
void Start()
{
mTrackableBehavior = GetComponent<TrackableBehaviour>();
if (mTrackableBehavior)
{
mTrackableBehavior.RegisterTrackableEventHandler(this);
}
}
public void OnTrackableStateChanged(TrackableBehaviour.Status previousStatus, TrackableBehaviour.Status newStatus)
{
if(newStatus == TrackableBehaviour.Status.DETECTED || newStatus == TrackableBehaviour.Status.TRACKED || newStatus == TrackableBehaviour.Status.EXTENDED_TRACKED)
{
OnTrackingFound();
} else
{
OnTrackingLost();
}
}
private void OnTrackingFound()
{
Renderer[] rendererComponents = GetComponentsInChildren<Renderer>();
Collider[] colliderComponents = GetComponentsInChildren<Collider>();
for (int i = 0; i < this.transform.GetChildCount(); i++)
{
Debug.Log("Activating the children");
this.transform.GetChild(i).gameObject.SetActive(true);
}
foreach(Renderer component in rendererComponents)
{
component.enabled = true;
}
foreach(Collider component in colliderComponents)
{
component.enabled = true;
}
Debug.Log("Tracking of " + mTrackableBehavior.TrackableName + " found");
}
private void OnTrackingLost()
{
Renderer[] rendererComponents = GetComponentsInChildren<Renderer>();
Collider[] colliderComponents = GetComponentsInChildren<Collider>();
for (int i = 0; i < this.transform.GetChildCount(); i++)
{
Debug.Log("Deactivating children");
this.transform.GetChild(i).gameObject.SetActive(false);
}
foreach (Renderer component in rendererComponents)
{
component.enabled = false;
}
foreach (Collider component in colliderComponents)
{
component.enabled = false;
}
Debug.Log("Tracking of " + mTrackableBehavior.TrackableName + " lost");
}
}
In this class, I've only activated the components when the tracking of the markers is found! Otherwise it will be deactivated, and when the tracking is found again, then it will be displayed as the way it was before losing track.
I've added this script to the ARCamera component. Works fine here!