Metaverse is a word conveying different meanings to different persons and to date some 150 definitions have been formulated. In this document the word metaverse is characterised as “a system that captures data from the real world (in the following, called Universe[1]), processes it, and combines it with internally generated data to create virtual environments that users can interact with”. So far, the developers of many systems responding to this characterisation have made technology decisions that best responded to their needs, often without considering the choices that other developers might have made for similar purposes.

Recently, however, there have been mounting concerns that such metaverse “walled gardens” do not fully exploit the opportunities offered by current and expected technologies. Calls have been made to make metaverse instances (in the following, M-Instances) “Interoperable”.

MPAI – Moving Picture, Audio, and Data Coding by Artificial Intelligence – the international, unaffiliated, non-profit organisation developing standards for AI-based data coding – has provided initial contributions to M-Instance Interoperability with two Technical Reports:

  1. Technical Report: MPAI Metaverse Model (MPAI-MMM) – Functionalities [1] has introduced the following elements:
    • A set of definitions.
    • A set of assumptions, the most important of which are that metaverse:
      • Is a broad notion that may be used by different industries for different purposes.
      • Needs technologies, some of which do not even exist with satisfactory performance.
      • The notion of profile may help improve Interoperability.
    • A collection of high-level use cases.
    • A collection of exemplary service providers.
    • An organised set of ~150 Functionalities.
    • A review of the main metaverse-enabling technologies.
    • An analysis of metaverse governance needs.
    • The MPAI metaverse standardisation roadmap.
  1. Technical Report: MPAI Metaverse Model (MPAI-MMM) – Functionality Profiles [11] has introduced the following elements:
    • A revised and extended list of definitions.
    • An operation model of the metaverse based on the notion of Processes performing or requesting other Processes to perform Actions on Items (Items are Data supported by an M-Instance).
    • A specification of a first set of Actions, Items, and Data Types enabling:
      • Detailed descriptions of Use Cases using Actions, Items, and Data Types.
      • The definition of Functionality Profiles, i.e., subsets of Actions, Items, and Data Types that satisfy a selected subset of identified Functionalities.
    • A collection of representative use cases tested against the Operation Model.
    • Four initial Functionality Profiles.

Technical Specification – MPAI Metaverse Model (MPAI-MMM) – Architecture provides means to achieve M-Instance Interoperability by specifying the Functional Requirements of Processes, Actions, Items, and Data Types that allow Interoperation of two or more M-Instances implementing the Operation Model, executing Processes, and producing Data with Formats that comply with the Functional Requirements of this Technical Specification, possibly via a Conversion Service.

Chapters, Sections, and Annexes are Normative unless they are explicitly identified as Informative.

[1] Words beginning with a capital letter are defined in Chapter 3.