Question Reset MARS

Hi there! There are two things you might want to pause or reset. One is AR features like plane scanning and point cloud update, and the other is the state of the proxies and the MARS query system.

As you guessed, the way to reset the state of your queries is to deactivate your MARS proxy objects. As for the AR features, you can call the Start/Stop methods on interfaces like `IUsesPlaneFinding` as well as Reset on the `IUsesSessionControl` interface to reset the session origin and all AR data. Reset may not be exactly what you want, though, because the individual AR systems will still be running and, for example, detecting planes.

Another surefire way to reset everything is to just switch scenes. MARS is set up to reload all of its modules and systems when you switch scenes, either at runtime or in the Editor. Of course, this comes with a visible transition which is best hidden by a full screen menu or some other visible transition that hides the camera feed.

Hope this helps!

 

The intent is that you use them as extension methods. Our system will hook up scene objects to their functionality provider, and you can call `this.Foo()`

In your case, you would just add a MonoBehaviour to your scene that looks something like this:

Code (CSharp):

1. using System;
2. using TMPro;
3. using Unity.MARS.Providers;
4. using Unity.MARS.Settings;
5. using Unity.XRTools.ModuleLoader;
6. using UnityEngine;
7. using UnityEngine.Events;
8.  
9. namespace Unity.MARS
10. {
11.     public class SessionUI : MonoBehaviour, IUsesFunctionalityInjection
12.     {
13.         class Subscriber : IUsesSessionControl, IUsesPointCloud, IUsesPlaneFinding, IUsesMarkerTracking
14.         {
15.             IProvidesSessionControl IFunctionalitySubscriber<IProvidesSessionControl>.provider { get; set; }
16.             IProvidesPointCloud IFunctionalitySubscriber<IProvidesPointCloud>.provider { get; set; }
17.             IProvidesPlaneFinding IFunctionalitySubscriber<IProvidesPlaneFinding>.provider { get; set; }
18.             IProvidesMarkerTracking IFunctionalitySubscriber<IProvidesMarkerTracking>.provider { get; set; }
19.         }
20.  
21.         [Serializable]
22.         class PauseEvent : UnityEvent<bool> { }
23.  
24.         const string k_PauseText = "Pause";
25.         const string k_ResumeText = "Resume";
26.  
27. #pragma warning disable 649
28.         [SerializeField]
29.         TextMeshProUGUI m_Text;
30. #pragma warning restore 649
31.  
32.         readonly Subscriber m_Subscriber = new Subscriber();
33.  
34.         IProvidesFunctionalityInjection IFunctionalitySubscriber<IProvidesFunctionalityInjection>.provider { get; set; }
35.  
36.         void Start()
37.         {
38.             m_Text.text = MARSCore.instance.paused ? k_ResumeText : k_PauseText;
39.             this.InjectFunctionalitySingle(m_Subscriber);
40.         }
41.  
42.         public void TogglePaused()
43.         {
44.             var paused = MARSCore.instance.paused;
45.             if (paused)
46.             {
47.                 m_Text.text = k_PauseText;
48.                 paused = false;
49.             }
50.             else
51.             {
52.                 m_Text.text = k_ResumeText;
53.                 paused = true;
54.             }
55.  
56.             MARSCore.instance.paused = paused;
57.             if (paused)
58.             {
59.                 if (m_Subscriber.HasProvider<IProvidesPointCloud>())
60.                     m_Subscriber.StopDetectingPoints();
61.  
62.                 if (m_Subscriber.HasProvider<IProvidesPlaneFinding>())
63.                     m_Subscriber.StopDetectingPlanes();
64.  
65.                 if (m_Subscriber.HasProvider<IProvidesMarkerTracking>())
66.                     m_Subscriber.StopTrackingMarkers();
67.             }
68.             else
69.             {
70.                 if (m_Subscriber.HasProvider<IProvidesPointCloud>())
71.                     m_Subscriber.StartDetectingPoints();
72.  
73.                 if (m_Subscriber.HasProvider<IProvidesPlaneFinding>())
74.                     m_Subscriber.StartDetectingPlanes();
75.  
76.                 if (m_Subscriber.HasProvider<IProvidesMarkerTracking>())
77.                     m_Subscriber.StartTrackingMarkers();
78.             }
79.         }
80.  
81.         public void TriggerSessionReset()
82.         {
83.             if (m_Subscriber.HasProvider<IProvidesSessionControl>())
84.                 m_Subscriber.ResetSession();
85.         }
86.     }
87. }
88.  

This is from an app that we use to test MARS, and is hooked up to a UI canvas with buttons and a text object to indicate status. You may notice that the `Subscriber` sub-class is actually what implements `IUsesSessionControl`, etc. This allows us to include this script in our scene without adding a requirement for planes, point clouds, and image markers, but still to control those systems if they are active.

Feel free to keep the questions coming. If this example doesn't make sense, I can provide a simpler one that just covers the basics.

Cheers!

 

Hi there, @secret_portal_mike!

The `TriggerSessionReset` method in the script I pasted should do what you are describing, which resets the whole AR session including scanned surfaces. @EarMaster was this not working for you?

Edit: sorry--I pressed enter trying to fill in the @mention and it hit reply instead!

 

Hi there! `TriggerSessionReset` should be working, but if `HasProvider` is returning false, then there must be an issue where the face tracking configuration doesn't have a session control provider. We will investigate this issue and get back to you with more information.

Something you could try is to "promote" session control in this class which would tell the system you require a session control provider. To do this, simply move the `IUsesSessionControl` interface from the `Subscriber` nested class up to the `SessionUI` class definition and move the provider property out of the subscriber class. Then you should be able to just call `this.ResetSession()` in `TriggerSessionReset`. You would end up with something more similar. to the snippet I posted here https://forum.unity.com/threads/turn-off-mars-camera.1044880/#post-6773267