Resolved Where is World Space p(0,0,0) in any AR Scene?

Trying to fully understand World Space coordinates in AR.

Where does World Space p(0,0,0) or the World Space origin exist?
Is this the same as the current Camera origin-device location?
Or is it created once when the application launches (ie fixed and static)?

If the latter how is it calculated?

 

From my experience world zero is where your device is at startup. At least for standard back camera AR. Not sure for front facing (selfie) camera mode.

ARFoundation docs on AR Session Origin;
"Because AR devices provide their data in "session space", which is an unscaled space relative to the beginning of the AR session, the ARSessionOrigin performs the appropriate transformation into Unity space."

 

Yep thanks!