Multiuser synchronization of real and virtual worlds

A computer-implemented method to provide a virtual experience for multiple users without an absolute positioning system, the method comprising:

• a. obtaining, by portable electronic devices respectively associated with a plurality of users sharing a real-world space, relative measurements of real-world alignments between users, including relative positions and relative orientations, without requiring absolute coordinates, GPS, or beacons;
• b. forming, from the relative measurements, a graph of alignments linking the users;
• c. placing user viewpoints into a shared virtual space based on the graph of alignments for each user;
• and
• d. correlating the shared virtual space into the real-world space so that user physical locations correspond to user virtual locations as mapped via that correlation,
• further comprising detecting that users' relative positions become misaligned due to accumulative flaws in the relative movement sensor and/or due to a change in the correlation of the shared virtual space into the real-world space.

A multi-user extended-reality system comprising:

• a. a plurality of portable electronic devices respectively associated with a plurality of users sharing a real-world space, each portable electronic device including a relative movement sensor configured to track relative changes in position and orientation of an associated user by directly sensing positions and orientations with respect to at least one other portable electronic device, without an absolute positioning system, GPS, or beacons;
• b. one or more processors configured to obtain relative measurements of real-world alignments between users to form a graph of alignments wherein the graph is produced from the directly sensed relative position and orientation;
• c. one or more processors configured to place respective user viewpoints or avatars in a shared virtual space based on the graph of alignments;
• and
• d. one or more processors configured to correlate the shared virtual space into the real-world space via a correlation and, after a starting alignment, maintain positions and orientations of the user viewpoints or avatars in the shared virtual space based on tracked relative movements while using the correlation.

A multi-user extended-reality system comprising:

• a. a plurality of portable electronic devices respectively associated with a plurality of users sharing a real-world space, each portable electronic device including a relative movement sensor configured to track relative changes in position and orientation of an associated user without an absolute positioning system, GPS, or beacons;
• b. one or more processors configured to obtain relative measurements of real-world alignments between users to form a graph of alignments;
• c. one or more processors configured to place respective user viewpoints or avatars in a shared virtual space based on the graph of alignments;
• and
• d. one or more processors configured to correlate the shared virtual space into the real-world space via a correlation and, after a starting alignment, maintain positions and orientations of the user viewpoints or avatars in the shared virtual space based on tracked relative movements while using the correlation,
• wherein, responsive to detecting misalignment due to accumulative flaws in the relative movement sensor and/or due to a change in the correlation of the shared virtual space into the real-world space, the one or more processors are configured to perform at least one of:
• e. resetting alignment by taking fresh relative measurements between users;
• f. temporarily accepting an error and healing differing correlations back toward alignment through a series of small, smooth movements;
• or
• g. forcing correlations back together by selecting an aligned correlation and requiring at least one user to move to a new physical location.