I did file a bug within the Unity Editor regarding this issue. Ticket is open since March 17th, 2017 but got no answer nor update so far.
I simply want to notify Unity Editor users about it until it get fixed (or at least documented if that’s the intended behaviour).
The “bug” is related to the WorldAnchor.isLocated property (https://docs.unity3d.com/ScriptReference/VR.WSA.WorldAnchor-isLocated.html).
When the WorldAnchor is not located, you might want to listen to the OnTrackingChanged event. As soon as it gets fired, the callback provides the subject WorldAnchor and the updated “isLocated” value.
Thing is, if you bypass the provided value and access directly the property (worldAnchor.isLocated), the wrong value will be returned.
Indeed, it seems isLocated internal property is updated AFTER the OnTrackingChanged callback gets fired.
If it is the intended behaviour, I guess it should be mentioned in the documentation to avoid any confusion.
How to reproduce (Nakda -myself- post): WorldAnchor.isLocated not updated properly · Issue #563 · microsoft/MixedRealityToolkit-Unity · GitHub
Tags: HoloLens, VR, WorldAnchor, OnTrackingChanged, isLocated