Some objects disappear after relocalizing from backgrounded state

mozilla-mobile / webxr-ios

An iOS app for testing WebXR

Mozilla Public License 2.0

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Some objects disappear after relocalizing from backgrounded state #161

Closed robomex closed 5 years ago

robomex commented 5 years ago

To reproduce:

Go to 'World Sensing' example
Scan some planes
Background the app
Foreground the app
Relocalize
Planes rendered by the site disappear (whereas the ARKit planes, as visible using the debug option, remain)

Planes/anchors don't disappear in the similar sessionInterruptionEnded, nor do user-placed anchors (e.g. boxes in the Hit Testing example) disappear after relocalizing from a backgrounded state.

The device-side, ARKit plane anchors aren't disappearing – it's planeAnchors disappearing from the objects array that's passed to the WebXR page for it to render (e.g. in the 'World Sensing' example).

blairmacintyre commented 5 years ago

just so I understand: are the planeAnchors still being sent into the web page? is the bug on the javascript side, or the app side?

robomex commented 5 years ago

I believe I've narrowed the bug down to some older app-side code dealing with resuming sessions – let me look at it/test it some more and I'll plan on either committing a fix or continuing the discussion here tomorrow.

robomex commented 5 years ago

The commit that addresses this issue lets ARKit handle automatic relocalization of the world map when the app is returning from being backgrounded as opposed to the previous method of explicitly resuming/running a session with the previously saved worldMap loaded as the initialWorldMap.

My testing didn't turn up any issues – but I'd really like to get others testing this code and the upcoming TestFlight that uses this code to see if any problems arise.