Persistent Cloud Anchors allows you to create a 3D feature map of a scene, place anchors onto that 3D feature map, and then resolve those anchors across multiple devices. Persistent anchors, in particular, have the ability to last over an extended period of time.

Examples of use cases:

• Working together on a redesign of your home throughout the year
• Leaving AR notes for your friends around an amusement park
• Hiding AR objects at specific places around the world to be discovered by others

https://developers.google.com/ar/develop/call-for-collaborators#persistent_cloud_anchors

Introducing ARKit 3

http://www.codinglabs.net/article_world_view_projection_matrix.aspx

https://www.bfh.ch/ti/de/aktuell/news/diplomfeier-08-03-2019/

https://www.research-collection.ethz.ch/bitstream/handle/20.500.11850/43288/eth-7684-01.pdf?sequence=1