Here is Jane’s explanation in another thread:
imagine this: you use the magic mat or some other surface with the markers. they have such a placement , where optimal tracking of markers is always possible (like 3-5 markers always in FOV of the scanner), because they aren’t obstructed by some object on/over them. As such, you have a greater precision and less stitching (volumetric) errors when scanning some object on such marker surface.
now, scanning an object on such surface starting on part with good marker visibility the scanner will of course always know its position. even going to areas with lesser visible markers ,because some are obstructed by the object itself, it will keep good tracking because of overlayed prescanned marker position.
I am sure , there will be a demonstration video by revopoint and/or pop 3 plus tester anytime got better visualisation. It would be great see a direct comparison of scanning the same object with “normal” and global marker tracking mode. @Revopoint-Jane
cheers