The context is: ARSessionDelegate func session(_ session: ARSession, didAdd anchors: [ARAnchor]) {}
Upon Image Detection, place an overlay of a RC Entity at the ImageAnchor location.
Using IOS 14, I have been reliably using: mySceneAnchorEntity = AnchorEntity(anchor: imageAnchor) to render additive RC scene content. Additive model entities render correctly in the field of view.
When I upgraded to IOS 15 using the same code that had been working for many (~12) months on all versions of IOS 14, my code failed to render any RC scene content. I get a ghosting of all of the render content in the proper location, but visible only for a moment, then it disappears.
So, I finally found the root cause of the issue. It appears that IOS 15 only renders correctly in my application using: mySceneAnchorEntity = AnchorEntity(world: imageAnchor.transform).
This led to many frustrating days of debugging to find the root cause. As a side note, IOS 14 renders RC scene entities correctly using both variants of AnchorEntity: mySceneAnchorEntity = AnchorEntity(anchor: imageAnchor) and mySceneAnchorEntity = AnchorEntity(world: imageAnchor.transform)
So, this leads me to believe there is an issue with the behavior of IOS 15 with the following version of AnchorEntity: mySceneAnchorEntity = AnchorEntity(anchor: imageAnchor)