MRTK V2 - Visualization of Spatial Awareness Mesh is not working properly

Question

In my project I'm using a button that enables and disables spatial mapping/awareness. It works quite good, in 7 times out of 10. The following behaviour can be observed in the other 3 times. By disabling the spatial-map-mesh (polygones), they disappear to 90%. But 10% stays where it is. Repeated pressing of my button (dis/enable spatial mapping) does not help, the 10% just stays. Any suggestions what the reason for that behaivour could be?

Code Observer:

public void ToggleObservers()
{
    if (SpatialAwarenessSystem == null) return;

    // If running → stop "running"
    if (_isObserverRunning)
    {
        SetVisualizationOfSpatialMapping(SpatialAwarenessMeshDisplayOptions.None);
        SpatialAwarenessSystem.SuspendObservers();
        _isObserverRunning = false;

        // Disabling the whole system boosts performance ~+5fps
        if (ShouldSpatialSystemBeDisabled)
            SpatialAwarenessSystem.Disable();

    }// Else start spatial mapping
    else
    {
        SpatialAwarenessSystem.Enable();
        SetVisualizationOfSpatialMapping(SpatialAwarenessMeshDisplayOptions.Visible);
        SpatialAwarenessSystem.ResumeObservers();
        _isObserverRunning = true;
    }
}

Code Set Visualtization of Spatial Mapping:

public void SetVisualizationOfSpatialMapping(SpatialAwarenessMeshDisplayOptions option)
{
    if (CoreServices.SpatialAwarenessSystem is IMixedRealityDataProviderAccess provider)
    {
        foreach (var observer in provider.GetDataProviders())
        {
            if (observer is IMixedRealitySpatialAwarenessMeshObserver meshObs)
            {
                meshObs.DisplayOption = option;
            }
        }
    }
}

Edit: Bug Report on Github.

Answer 1

I also hit this issue. Until this is fixed in MRTK, you can patch this.

Edit this file:

MixedRealityToolkit.Providers\WindowsMixedReality\WindowsMixedRealitySpatialMeshObserver.cs

Find the suspend function, and add the code between // Begin Patch and // End Patch:

public override void Suspend()
{
    #if UNITY_WSA
    if (!IsRunning)
    {
        Debug.LogWarning("The Windows Mixed Reality spatial observer is currently stopped.");
        return;
    }

    // UpdateObserver keys off of this value to stop observing.
    IsRunning = false;

    // Clear any pending work.
    meshWorkQueue.Clear();

    // Begin Patch
    if (outstandingMeshObject != null)
    {
        ReclaimMeshObject(outstandingMeshObject);
        outstandingMeshObject = null;
    }
    // End Patch
    #endif // UNITY_WSA
}