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%%% Title = "XR Fragments" area = "Internet" workgroup = "Internet Engineering Task Force"
[seriesInfo] name = "XR-Fragments" value = "draft-XRFRAGMENTS-leonvankammen-00" stream = "IETF" status = "informational"
date = 2023-04-12T00:00:00Z
author initials="L.R." surname="van Kammen" fullname="L.R. van Kammen"
%%%
.# Abstract
This draft offers a specification for 4D URLs & navigation, to link 3D scenes and text together with- or without a network-connection.
The specification promotes spatial addressibility, sharing, navigation, query-ing and tagging interactive (text)objects across for (XR) Browsers.
XR Fragments allows us to enrich existing dataformats, by recursive use of existing proven technologies like URI Fragments and BibTags notation.
Almost every idea in this document is demonstrated at https://xrfragment.org
{mainmatter}
Introduction
How can we add more features to existing text & 3D scenes, without introducing new dataformats?
Historically, there's many attempts to create the ultimate markuplanguage or 3D fileformat.
Their lowest common denominator is: (co)authoring using plain text.
Therefore, XR Macros allows us to enrich/connect existing dataformats, by offering a polyglot notation based on existing notations:
- getting/setting common used 3D properties using querystring- or JSON-notation
NOTE: The chapters in this document are ordered from highlevel to lowlevel (technical) as much as possible
Core principle
- XR Macros use querystrings, but are HTML-agnostic (though pseudo-XR Fragment browsers can be implemented on top of HTML/Javascript).
- XR Macros represents setting/getting common used properties found in all popular 3D frameworks/(game)editors/internet browsers.
Conventions and Definitions
See appendix below in case certain terms are not clear.
List of XR Macros
(XR) Macros can be embedded in 3D assets/scenes.
</br
Macros allow a limited logic-layer, by recursive (economic) use of the querystring syntax (which the XR Fragment parser already uses).
The only addition is the | symbol to roundrobin variable values.
Macros also act as events, so more serious scripting languages can react to them as well.
| custom property | value | assign (rr) variable ? | execute opcode? | show contextmenu? |
|---|---|---|---|---|
| !clickme | day|noon|night | yes | not yet | only when multiple props start with ! |
| day | bg=1,1,1 | no | yes | no |
| noon | bg=0.5,0.5,0.5 | yes | yes | no |
| night | bg=0,0,0&foo=2 | yes | yes | no |
| custom property | value | assign (rr) variable ? | execute opcode? | show contextmenu? |
|---|---|---|---|---|
| !turnofflights | night | no | yes | yes because of !clickme |
| !clickme | day|noon|night | yes | not yet | yes because of !clickme |
| day | bg=1,1,1 | no | yes | no |
| noon | bg=0.5,0.5,0.5 | yes | yes | no |
| night | bg=0,0,0&foo=2 | yes | yes | no |
lazy evaluation:
| custom property | value | copy verbatim to URL? | (rr) variable [assingment]? |
|---|---|---|---|
| href | #cyclepreset | yes | no |
| cyclepreset | day|noon|night | no | (yes) yes |
| day | bg=1,1,1 | no | yes [yes] |
| noon | bg=0.5,0.5,0.5 | no | yes [yes] |
| night | bg=0,0,0&foo=2 | no | yes [yes] |
Security Considerations
IANA Considerations
This document has no IANA actions.
Acknowledgments
Appendix: Definitions
| definition | explanation |
|---|---|
| human | a sentient being who thinks fuzzy, absorbs, and shares thought (by plain text, not markuplanguage) |
| scene | a (local/remote) 3D scene or 3D file (index.gltf e.g.) |
| 3D object | an object inside a scene characterized by vertex-, face- and customproperty data. |
| metadata | custom properties of text, 3D Scene or Object(nodes), relevant to machines and a human minority (academics/developers) |
| XR fragment | URI Fragment with spatial hints like #pos=0,0,0&t=1,100 e.g. |
| src | (HTML-piggybacked) metadata of a 3D object which instances content |
| href | (HTML-piggybacked) metadata of a 3D object which links to content |
| query | an URI Fragment-operator which queries object(s) from a scene like #q=cube |
| visual-meta | visual-meta data appended to text/books/papers which is indirectly visible/editable in XR. |
| requestless metadata | metadata which never spawns new requests (unlike RDF/HTML, which can cause framerate-dropping, hence not used a lot in games) |
| FPS | frames per second in spatial experiences (games,VR,AR e.g.), should be as high as possible |
| introspective | inward sensemaking ("I feel this belongs to that") |
| extrospective | outward sensemaking ("I'm fairly sure John is a person who lives in oklahoma") |
◻ |
ascii representation of an 3D object/mesh |
| (un)obtrusive | obtrusive: wrapping human text/thought in XML/HTML/JSON obfuscates human text into a salad of machine-symbols and words |
| BibTeX | simple tagging/citing/referencing standard for plaintext |
| BibTag | a BibTeX tag |