xrfragment/doc/RFC_XR_Fragments.txt

841 lines
36 KiB
Plaintext
Raw Normal View History

2023-09-01 14:20:02 +02:00
Internet Engineering Task Force L.R. van Kammen
2023-09-04 21:20:59 +02:00
Internet-Draft 4 September 2023
2023-09-01 14:20:02 +02:00
Intended status: Informational
2023-09-04 21:20:59 +02:00
2023-09-01 14:20:02 +02:00
XR Fragments
draft-XRFRAGMENTS-leonvankammen-00
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,
2023-09-04 21:20:59 +02:00
navigation, query-ing and tagging interactive (text)objects across
for (XR) Browsers.
2023-09-01 14:20:02 +02:00
XR Fragments allows us to enrich existing dataformats, by recursive
2023-09-04 21:20:59 +02:00
use of existing proven technologies like URI Fragments
(https://en.wikipedia.org/wiki/URI_fragment) and visual-meta
2023-09-01 14:20:02 +02:00
(https://visual-meta.info).
Status of This Memo
This Internet-Draft is submitted in full conformance with the
provisions of BCP 78 and BCP 79.
Internet-Drafts are working documents of the Internet Engineering
Task Force (IETF). Note that other groups may also distribute
working documents as Internet-Drafts. The list of current Internet-
Drafts is at https://datatracker.ietf.org/drafts/current/.
Internet-Drafts are draft documents valid for a maximum of six months
and may be updated, replaced, or obsoleted by other documents at any
time. It is inappropriate to use Internet-Drafts as reference
material or to cite them other than as "work in progress."
2023-09-04 21:20:59 +02:00
This Internet-Draft will expire on 7 March 2024.
2023-09-01 14:20:02 +02:00
Copyright Notice
Copyright (c) 2023 IETF Trust and the persons identified as the
document authors. All rights reserved.
2023-09-04 21:20:59 +02:00
This document is subject to BCP 78 and the IETF Trust's Legal
Provisions Relating to IETF Documents (https://trustee.ietf.org/
license-info) in effect on the date of publication of this document.
Please review these documents carefully, as they describe your rights
and restrictions with respect to this document. Code Components
2023-09-01 14:20:02 +02:00
2023-09-04 21:20:59 +02:00
van Kammen Expires 7 March 2024 [Page 1]
2023-09-01 14:20:02 +02:00
2023-09-02 21:44:57 +02:00
Internet-Draft XR Fragments September 2023
2023-09-01 14:20:02 +02:00
extracted from this document must include Revised BSD License text as
described in Section 4.e of the Trust Legal Provisions and are
provided without warranty as described in the Revised BSD License.
Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 2
2023-09-04 21:20:59 +02:00
2. Conventions and Definitions . . . . . . . . . . . . . . . . . 3
3. Core principle . . . . . . . . . . . . . . . . . . . . . . . 4
4. List of URI Fragments . . . . . . . . . . . . . . . . . . . . 4
5. List of metadata for 3D nodes . . . . . . . . . . . . . . . . 4
6. Navigating 3D . . . . . . . . . . . . . . . . . . . . . . . . 5
7. Embedding 3D content . . . . . . . . . . . . . . . . . . . . 5
8. Text in XR (tagging,linking to spatial objects) . . . . . . . 6
8.1. Default Data URI mimetype . . . . . . . . . . . . . . . . 8
8.2. URL and Data URI . . . . . . . . . . . . . . . . . . . . 9
8.3. BibTeX as lowest common denominator for tagging/triple . 10
8.4. XR text (BibTeX) example parser . . . . . . . . . . . . . 11
9. HYPER copy/paste . . . . . . . . . . . . . . . . . . . . . . 13
10. XR Fragment queries . . . . . . . . . . . . . . . . . . . . . 13
10.1. including/excluding . . . . . . . . . . . . . . . . . . 14
10.2. Query Parser . . . . . . . . . . . . . . . . . . . . . . 14
10.3. XR Fragment URI Grammar . . . . . . . . . . . . . . . . 15
11. Security Considerations . . . . . . . . . . . . . . . . . . . 15
12. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 15
13. Acknowledgments . . . . . . . . . . . . . . . . . . . . . . . 15
2023-09-01 14:20:02 +02:00
1. Introduction
How can we add more features to existing text & 3D scenes, without
2023-09-04 21:20:59 +02:00
introducing new dataformats?
Historically, there's many attempts to create the ultimate
markuplanguage or 3D fileformat.
However, thru the lens of authoring their lowest common denominator
is still: plain text.
XR Fragments allows us to enrich existing dataformats, by recursive
use of existing technologies:
1. addressibility and navigation of 3D scenes/objects: URI Fragments
(https://en.wikipedia.org/wiki/URI_fragment) + src/href spatial
metadata
2. hasslefree tagging across text and spatial objects using BiBTeX
(visual-meta (https://visual-meta.info) e.g.)
| NOTE: The chapters in this document are ordered from highlevel to
| lowlevel (technical) as much as possible
van Kammen Expires 7 March 2024 [Page 2]
Internet-Draft XR Fragments September 2023
2023-09-01 14:20:02 +02:00
2. Conventions and Definitions
2023-09-04 21:20:59 +02:00
+===============+===========================================+
| 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 |
| | (#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 (#q=cube) |
+---------------+-------------------------------------------+
| visual-meta | visual-meta (https://visual.meta.info) |
| | data appended to text which is indirectly |
| | visible/editable in XR. |
+---------------+-------------------------------------------+
| requestless | opposite of networked metadata (RDF/HTML |
| metadata | request-fanouts easily 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") |
van Kammen Expires 7 March 2024 [Page 3]
Internet-Draft XR Fragments September 2023
+---------------+-------------------------------------------+
| ◻ | ascii representation of an 3D object/mesh |
+---------------+-------------------------------------------+
Table 1
3. Core principle
XR Fragments strives to serve humans first, machine(implementations)
later, by ensuring hasslefree text-to-thought feedback loops.
This also means that the repair-ability of machine-matters should be
human friendly too (not too complex).
| "When a car breaks down, the ones without turbosupercharger are
| easier to fix"
4. List of URI Fragments
+==========+=========+==============+============================+
| fragment | type | example | info |
+==========+=========+==============+============================+
| #pos | vector3 | #pos=0.5,0,0 | positions camera to xyz- |
| | | | coord 0.5,0,0 |
+----------+---------+--------------+----------------------------+
| #rot | vector3 | #rot=0,90,0 | rotates camera to xyz- |
| | | | coord 0.5,0,0 |
+----------+---------+--------------+----------------------------+
| #t | vector2 | #t=500,1000 | sets animation-loop range |
| | | | between frame 500 and 1000 |
+----------+---------+--------------+----------------------------+
| #...... | string | #.cubes | object(s) of interest |
| | | #cube | (fragment to object name |
| | | | or class mapping) |
+----------+---------+--------------+----------------------------+
Table 2
| xyz coordinates are similar to ones found in SVG Media Fragments
5. List of metadata for 3D nodes
+=======+========+================+============================+
| key | type | example (JSON) | info |
+=======+========+================+============================+
| name | string | "name": "cube" | available in all 3D |
| | | | fileformats & scenes |
+-------+--------+----------------+----------------------------+
| class | string | "class": | available through custom |
2023-09-01 14:20:02 +02:00
2023-09-04 21:20:59 +02:00
van Kammen Expires 7 March 2024 [Page 4]
2023-09-01 14:20:02 +02:00
2023-09-02 21:44:57 +02:00
Internet-Draft XR Fragments September 2023
2023-09-01 14:20:02 +02:00
2023-09-04 21:20:59 +02:00
| | | "cubes" | property in 3D fileformats |
+-------+--------+----------------+----------------------------+
| href | string | "href": | available through custom |
| | | "b.gltf" | property in 3D fileformats |
+-------+--------+----------------+----------------------------+
| src | string | "src": | available through custom |
| | | "#q=cube" | property in 3D fileformats |
+-------+--------+----------------+----------------------------+
2023-09-01 14:20:02 +02:00
2023-09-04 21:20:59 +02:00
Table 3
2023-09-01 14:20:02 +02:00
2023-09-04 21:20:59 +02:00
Popular compatible 3D fileformats: .gltf, .obj, .fbx, .usdz, .json
(THREEjs), COLLADA and so on.
| NOTE: XR Fragments are file-agnostic, which means that the
| metadata exist in programmatic 3D scene(nodes) too.
6. Navigating 3D
2023-09-01 14:20:02 +02:00
Here's an ascii representation of a 3D scene-graph which contains 3D
2023-09-04 21:20:59 +02:00
objects ◻ and their metadata:
+--------------------------------------------------------+
| |
| index.gltf |
| │ |
| ├── ◻ buttonA |
| │ └ href: #pos=1,0,1&t=100,200 |
| │ |
| └── ◻ buttonB |
| └ href: other.fbx | <-- file-agnostic (can be .gltf .obj etc)
| |
+--------------------------------------------------------+
2023-09-01 14:20:02 +02:00
An XR Fragment-compatible browser viewing this scene, allows the end-
2023-09-04 21:20:59 +02:00
user to interact with the buttonA and buttonB.
In case of buttonA the end-user will be teleported to another
location and time in the *current loaded scene*, but buttonB will
*replace the current scene* with a new one (other.fbx).
2023-09-01 14:20:02 +02:00
2023-09-04 21:20:59 +02:00
7. Embedding 3D content
2023-09-01 14:20:02 +02:00
2023-09-04 21:20:59 +02:00
Here's an ascii representation of a 3D scene-graph with 3D objects
(&#9723;) which embeds remote & local 3D objects (&#9723;) (without)
using queries:
2023-09-01 14:20:02 +02:00
2023-09-04 21:20:59 +02:00
van Kammen Expires 7 March 2024 [Page 5]
2023-09-02 21:44:57 +02:00
Internet-Draft XR Fragments September 2023
2023-09-04 21:20:59 +02:00
+--------------------------------------------------------+ +-------------------------+
| | | |
| index.gltf | | ocean.com/aquarium.fbx |
| │ | | │ |
| ├── ◻ canvas | | └── ◻ fishbowl |
| │ └ src: painting.png | | ├─ ◻ bass |
| │ | | └─ ◻ tuna |
| ├── ◻ aquariumcube | | |
| │ └ src: ://rescue.com/fish.gltf#q=bass%20tuna | +-------------------------+
| │ |
| ├── ◻ bedroom |
| │ └ src: #q=canvas |
| │ |
| └── ◻ livingroom |
| └ src: #q=canvas |
| |
+--------------------------------------------------------+
An XR Fragment-compatible browser viewing this scene, lazy-loads and
projects painting.png onto the (plane) object called canvas (which is
copy-instanced in the bed and livingroom).
Also, after lazy-loading ocean.com/aquarium.gltf, only the queried
objects bass and tuna will be instanced inside aquariumcube.
Resizing will be happen accordingly to its placeholder object
(aquariumcube), see chapter Scaling.
8. Text in XR (tagging,linking to spatial objects)
We still think and speak in simple text, not in HTML or RDF.
It would be funny when people would shout <h1>FIRE!</h1> in case of
emergency.
Given the myriad of new (non-keyboard) XR interfaces, keeping text as
is (not obscuring with markup) is preferred.
Ideally metadata must come *later with* text, but not *obfuscate* the
text, or *in another* file.
| Humans first, machines (AI) later.
This way:
2023-09-02 21:44:57 +02:00
2023-09-04 21:20:59 +02:00
1. XR Fragments allows <b id="tagging-text">hasslefree XR text
tagging</b>, using BibTeX metadata *at the end of content* (like
visual-meta (https://visual.meta.info)).
2. XR Fragments allows hasslefree <a href="#textual-tag">textual
tagging</a>, <a href="#spatial-tag">spatial tagging</a>, and <a
href="#supra-tagging">supra tagging</a>, by mapping 3D/text
object (class)names to BibTeX
2023-09-02 21:44:57 +02:00
2023-09-04 21:20:59 +02:00
van Kammen Expires 7 March 2024 [Page 6]
Internet-Draft XR Fragments September 2023
3. inline BibTeX is the minimum required *requestless metadata*-
layer for XR text, RDF/JSON is great but optional (and too
verbose for the spec-usecases).
4. Default font (unless specified otherwise) is a modern monospace
font, for maximized tabular expressiveness (see the core
principle (#core-principle)).
5. anti-pattern: hardcoupling a mandatory *obtrusive markuplanguage*
or framework with an XR browsers (HTML/VRML/Javascript) (see the
core principle (#core-principle))
6. anti-pattern: limiting human introspection, by immediately
funneling human thought into typesafe, precise, pre-categorized
metadata like RDF (see the core principle (#core-principle))
This allows recursive connections between text itself, as well as 3D
objects and vice versa, using *BiBTeX-tags* :
+--------------------------------------------------+
| My Notes |
| |
| The houses seen here are built in baroque style. |
| |
| @house{houses, <----- XR Fragment triple/tag: tiny & phrase-matching BiBTeX
| url = {#.house} <------------------- XR Fragment URI
| } |
+--------------------------------------------------+
This sets up the following associations in the scene:
1. <b id="textual-tagging">textual tag</b>: text or spatial-
occurences named 'houses' is now automatically tagged with
'house'
2. <b id="spatial-tagging">spatial tag</b>: spatial object(s) with
class:house (#.house) is now automatically tagged with 'house'
3. <b id="supra-tagging">supra-tag</b>: text- or spatial-object
named 'house' (spatially) elsewhere, is now automatically tagged
with 'house'
Spatial wires can be rendered, words can be highlighted, spatial
objects can be highlighted, links can be manipulated by the user.
| The simplicity of appending BibTeX (humans first, machines later)
| is demonstrated by visual-meta (https://visual-meta.info) in
| greater detail, and makes it perfect for GUI's to generate
| (bib)text later. Humans can still view/edit the metadata
| manually, by clicking 'toggle metadata' on the 'back' (contextmenu
| e.g.) of any XR text, anywhere anytime.
van Kammen Expires 7 March 2024 [Page 7]
Internet-Draft XR Fragments September 2023
8.1. Default Data URI mimetype
The src-values work as expected (respecting mime-types), however:
2023-09-02 21:44:57 +02:00
The XR Fragment specification bumps the traditional default browser-
mimetype
text/plain;charset=US-ASCII
2023-09-04 21:20:59 +02:00
to a green eco-friendly:
text/plain;charset=utf-8;bibtex=^@
This indicates that any bibtex metadata starting with @ will
automatically get filtered out and:
* automatically detects textual links between textual and spatial
objects
2023-09-02 21:44:57 +02:00
2023-09-04 21:20:59 +02:00
It's concept is similar to literate programming. Its implications
are that local/remote responses can now:
2023-09-02 21:44:57 +02:00
2023-09-04 21:20:59 +02:00
* (de)multiplex/repair human text and requestless metadata (see the
core principle (#core-principle))
* no separated implementation/network-overhead for metadata (see the
core principle (#core-principle))
* ensuring high FPS: HTML/RDF historically is too 'requesty' for
game studios
* rich send/receive/copy-paste everywhere by default, metadata being
retained (see the core principle (#core-principle))
* less network requests, therefore less webservices, therefore less
servers, and overall better FPS in XR
2023-09-02 21:44:57 +02:00
2023-09-04 21:20:59 +02:00
| This significantly expands expressiveness and portability of human
| text, by *postponing machine-concerns to the end of the human
| text* in contrast to literal interweaving of content and
| markupsymbols (or extra network requests, webservices e.g.).
For all other purposes, regular mimetypes can be used (but are not
required by the spec).
To keep XR Fragments a lightweight spec, BiBTeX is used for text-
spatial object mappings (not a scripting language or RDF e.g.).
| Applications are also free to attach any JSON(LD / RDF) to spatial
| objects using custom properties (but is not interpreted by this
| spec).
van Kammen Expires 7 March 2024 [Page 8]
Internet-Draft XR Fragments September 2023
8.2. URL and Data URI
2023-09-02 21:44:57 +02:00
+--------------------------------------------------------------+ +------------------------+
| | | author.com/article.txt |
| index.gltf | +------------------------+
| │ | | |
| ├── ◻ article_canvas | | Hello friends. |
| │ └ src: ://author.com/article.txt | | |
2023-09-04 21:20:59 +02:00
| │ | | @friend{friends |
| └── ◻ note_canvas | | ... |
| └ src:`data:welcome human @...` | | } |
| | +------------------------+
2023-09-02 21:44:57 +02:00
| |
+--------------------------------------------------------------+
2023-09-04 21:20:59 +02:00
The enduser will only see welcome human and Hello friends rendered
spatially. The beauty is that text (AND visual-meta) in Data URI
promotes rich copy-paste. In both cases, the text gets rendered
immediately (onto a plane geometry, hence the name '_canvas'). The
XR Fragment-compatible browser can let the enduser access visual-
meta(data)-fields after interacting with the object (contextmenu
e.g.).
2023-09-02 21:44:57 +02:00
2023-09-04 21:20:59 +02:00
The mapping between 3D objects and text (src-data) is simple:
2023-09-02 21:44:57 +02:00
2023-09-04 21:20:59 +02:00
Example:
2023-09-01 14:20:02 +02:00
2023-09-04 21:20:59 +02:00
+------------------------------------------------------------------------------------+
| |
| index.gltf |
| │ |
| └── ◻ rentalhouse |
| └ class: house |
| └ ◻ note |
| └ src:`data: todo: call owner |
| @house{owner, |
| url = {#.house} |
| }` |
+------------------------------------------------------------------------------------+
2023-09-01 14:20:02 +02:00
2023-09-04 21:20:59 +02:00
Attaching visualmeta as src metadata to the (root) scene-node hints
the XR Fragment browser. 3D object names and classes map to name of
visual-meta glossary-entries. This allows rich interaction and
interlinking between text and 3D objects:
2023-09-01 14:20:02 +02:00
2023-09-04 21:20:59 +02:00
1. When the user surfs to https://.../index.gltf#AI the XR
Fragments-parser points the enduser to the AI object, and can
show contextual info about it.
2023-09-01 14:20:02 +02:00
2023-09-04 21:20:59 +02:00
van Kammen Expires 7 March 2024 [Page 9]
2023-09-02 21:44:57 +02:00
Internet-Draft XR Fragments September 2023
2023-09-04 21:20:59 +02:00
2. When (partial) remote content is embedded thru XR Fragment
queries (see XR Fragment queries), its related visual-meta can be
embedded along.
8.3. BibTeX as lowest common denominator for tagging/triple
The everything-is-text focus of BiBTex is a great advantage for
introspection, and perhaps a necessary bridge towards RDF
(extrospective). BibTeX-appendices (visual-meta e.g.) are already
adopted in the physical world (academic books), perhaps due to its
terseness & simplicity:
1. <b id="frictionless-copy-paste">frictionless copy/pasting</b> (by
humans) of (unobtrusive) content AND metadata
2. an introspective 'sketchpad' for metadata, which can (optionally)
mature into RDF later
+====================+==========================+=================+
| characteristic | Plain Text (with BibTeX) | RDF |
+====================+==========================+=================+
| perspective | introspective | extrospective |
+--------------------+--------------------------+-----------------+
| space/scope | local | world |
+--------------------+--------------------------+-----------------+
| everything is text | yes | no |
| (string) | | |
+--------------------+--------------------------+-----------------+
| leaves (dictated) | yes | no |
| text intact | | |
+--------------------+--------------------------+-----------------+
| markup language(s) | no (appendix) | ~4 different |
+--------------------+--------------------------+-----------------+
| polyglot format | no | yes |
+--------------------+--------------------------+-----------------+
| easy to copy/paste | yes | depends |
| content+metadata | | |
+--------------------+--------------------------+-----------------+
| easy to write/ | yes | depends |
| repair | | |
+--------------------+--------------------------+-----------------+
| easy to parse | yes (fits on A4 paper) | depends |
+--------------------+--------------------------+-----------------+
| infrastructure | selfcontained (plain | (semi)networked |
| storage | text) | |
+--------------------+--------------------------+-----------------+
| tagging | yes | yes |
+--------------------+--------------------------+-----------------+
| freeform tagging/ | yes | depends |
van Kammen Expires 7 March 2024 [Page 10]
Internet-Draft XR Fragments September 2023
2023-09-02 21:44:57 +02:00
2023-09-04 21:20:59 +02:00
| notes | | |
+--------------------+--------------------------+-----------------+
| specialized file- | no | yes |
| type | | |
+--------------------+--------------------------+-----------------+
| copy-paste | yes | depends |
| preserves metadata | | |
+--------------------+--------------------------+-----------------+
| emoji | yes | depends |
+--------------------+--------------------------+-----------------+
| predicates | free | pre-determined |
+--------------------+--------------------------+-----------------+
| implementation/ | no | depends |
| network overhead | | |
+--------------------+--------------------------+-----------------+
| used in (physical) | yes (visual-meta) | no |
| books/PDF | | |
+--------------------+--------------------------+-----------------+
| terse categoryless | yes | no |
| predicates | | |
+--------------------+--------------------------+-----------------+
| nested structures | no | yes |
+--------------------+--------------------------+-----------------+
Table 4
| To serve humans first, human 'fuzzy symbolical mind' comes first,
| and 'categorized typesafe RDF hive mind'
| (https://en.wikipedia.org/wiki/Borg)) later.
8.4. XR text (BibTeX) example parser
Here's a naive XR Text (de)multiplexer in javascript (which also
supports visual-meta start/end-blocks):
xrtext = {
decode: {
text: (str) => {
let meta={}, text='', last='', data = '';
str.split(/\r?\n/).map( (line) => {
if( !data ) data = last === '' && line.match(/^@/) ? line[0] : ''
if( data ){
if( line === '' ){
xrtext.decode.bibtex(data.substr(1),meta)
data=''
}else data += `${line}\n`
}
van Kammen Expires 7 March 2024 [Page 11]
Internet-Draft XR Fragments September 2023
2023-09-02 21:44:57 +02:00
2023-09-04 21:20:59 +02:00
text += data ? '' : `${line}\n`
last=line
})
return {text, meta}
},
bibtex: (str,meta) => {
let st = [meta]
str
.split(/\r?\n/ )
.map( s => s.trim() ).join("\n") // be nice
.replace( /}@/, "}\n@" ) // to authors
.replace( /},}/, "},\n}" ) // which struggle
.replace( /^}/, "\n}" ) // with writing single-line BiBTeX
.split( /\n/ ) //
.filter( c => c.trim() ) // actual processing:
.map( (s) => {
if( s.match(/(^}|-end})/) && st.length > 1 ) st.shift()
else if( s.match(/^@/) ) st.unshift( st[0][ s.replace(/(-start|,)/g,'') ] = {} )
else s.replace( /(\w+)\s*=\s*{(.*)}(,)?/g, (m,k,v) => st[0][k] = v )
})
return meta
}
},
encode: (text,meta) => {
if( text === false ){
if (typeof meta === "object") {
return Object.keys(meta).map(k =>
typeof meta[k] == "string"
? ` ${k} = {${meta[k]}},`
: `${ k.match(/[}{]$/) ? k.replace('}','-start}') : `${k},` }\n` +
`${ xrtext.encode( false, meta[k])}\n` +
`${ k.match(/}$/) ? k.replace('}','-end}') : '}' }\n`
.split("\n").filter( s => s.trim() ).join("\n")
)
.join("\n")
}
return meta.toString();
}else return `${text}\n${xrtext.encode(false,meta)}`
}
}
var {meta,text} = xrtext.decode.text(str) // demultiplex text & bibtex
meta['@foo{'] = { "note":"note from the user"} // edit metadata
xrtext.encode(text,meta) // multiplex text & bibtex back together
van Kammen Expires 7 March 2024 [Page 12]
Internet-Draft XR Fragments September 2023
2023-09-02 21:44:57 +02:00
2023-09-04 21:20:59 +02:00
| above can be used as a startingpoint for LLVM's to translate/
| steelman to any language.
2023-09-02 21:44:57 +02:00
2023-09-04 21:20:59 +02:00
9. HYPER copy/paste
2023-09-01 14:20:02 +02:00
2023-09-04 21:20:59 +02:00
The previous example, offers something exciting compared to simple
copy/paste of 3D objects or text. XR Fragment allows HYPER-copy/
paste: time, space and text interlinked. Therefore, the enduser in
an XR Fragment-compatible browser can copy/paste/share data in these
ways:
2023-09-01 14:20:02 +02:00
2023-09-04 21:20:59 +02:00
* time/space: 3D object (current animation-loop)
* text: TeXt object (including BiBTeX/visual-meta if any)
* interlinked: Collected objects by visual-meta tag
2023-09-01 14:20:02 +02:00
2023-09-04 21:20:59 +02:00
10. XR Fragment queries
2023-09-01 14:20:02 +02:00
2023-09-04 21:20:59 +02:00
Include, exclude, hide/shows objects using space-separated strings:
2023-09-01 14:20:02 +02:00
2023-09-04 21:20:59 +02:00
* #q=cube
* #q=cube -ball_inside_cube
* #q=* -sky
* #q=-.language .english
* #q=cube&rot=0,90,0
* #q=price:>2 price:<5
2023-09-01 14:20:02 +02:00
2023-09-04 21:20:59 +02:00
It's simple but powerful syntax which allows <b>css</b>-like class/
id-selectors with a searchengine prompt-style feeling:
2023-09-01 14:20:02 +02:00
2023-09-04 21:20:59 +02:00
1. queries are only executed when <b>embedded</b> in the asset/scene
(thru src). This is to prevent sharing of scene-tampered URL's.
2. search words are matched against 3D object names or metadata-
key(values)
3. # equals #q=*
4. words starting with . (.language) indicate class-properties
2023-09-01 14:20:02 +02:00
2023-09-04 21:20:59 +02:00
| *(*For example**: #q=.foo is a shorthand for #q=class:foo, which
| will select objects with custom property class:foo. Just a simple
| #q=cube will simply select an object named cube.
2023-09-02 21:44:57 +02:00
2023-09-04 21:20:59 +02:00
* see an example video here
(https://coderofsalvation.github.io/xrfragment.media/queries.mp4)
2023-09-01 14:20:02 +02:00
2023-09-04 21:20:59 +02:00
van Kammen Expires 7 March 2024 [Page 13]
Internet-Draft XR Fragments September 2023
2023-09-01 14:20:02 +02:00
2023-09-04 21:20:59 +02:00
10.1. including/excluding
|''operator'' | ''info'' | |* | select all objects (only allowed in
src custom property) in the <b>current</b> scene (<b>after</b> the
default [[predefined_view|predefined_view]] # was executed)| |- |
removes/hides object(s) | |: | indicates an object-embedded custom
property key/value | |. | alias for class: (.foo equals
class:foo | |> <| compare float or int number| |/ | reference to
root-scene.
Useful in case of (preventing) showing/hiding objects in nested
scenes (instanced by [[src]])
#q=-/cube hides object cube only in the root-scene (not nested cube
objects)
#q=-cube hides both object cube in the root-scene <b>AND</b> nested
skybox objects |
&#187; example implementation
(https://github.com/coderofsalvation/xrfragment/blob/main/src/3rd/js/
three/xrf/q.js) &#187; example 3D asset
(https://github.com/coderofsalvation/xrfragment/blob/main/example/
assets/query.gltf#L192) &#187; discussion
(https://github.com/coderofsalvation/xrfragment/issues/3)
10.2. Query Parser
Here's how to write a query parser:
1. create an associative array/object to store query-arguments as
objects
2. detect object id's & properties foo:1 and foo (reference regex:
/^.*:[><=!]?/ )
3. detect excluders like -foo,-foo:1,-.foo,-/foo (reference regex:
/^-/ )
4. detect root selectors like /foo (reference regex: /^[-]?\// )
5. detect class selectors like .foo (reference regex: /^[-]?class$/
)
6. detect number values like foo:1 (reference regex: /^[0-9\.]+$/ )
7. expand aliases like .foo into class:foo
8. for every query token split string on :
9. create an empty array rules
10. then strip key-operator: convert "-foo" into "foo"
11. add operator and value to rule-array
12. therefore we we set id to true or false (false=excluder -)
13. and we set root to true or false (true=/ root selector is
present)
14. we convert key '/foo' into 'foo'
15. finally we add the key/value to the store (store.foo =
{id:false,root:true} e.g.)
van Kammen Expires 7 March 2024 [Page 14]
Internet-Draft XR Fragments September 2023
2023-09-01 14:20:02 +02:00
2023-09-04 21:20:59 +02:00
| An example query-parser (which compiles to many languages) can be
| found here
| (https://github.com/coderofsalvation/xrfragment/blob/main/src/
| xrfragment/Query.hx)
2023-09-01 14:20:02 +02:00
2023-09-04 21:20:59 +02:00
10.3. XR Fragment URI Grammar
2023-09-01 14:20:02 +02:00
2023-09-04 21:20:59 +02:00
reserved = gen-delims / sub-delims
gen-delims = "#" / "&"
sub-delims = "," / "="
2023-09-01 14:20:02 +02:00
2023-09-04 21:20:59 +02:00
| Example: ://foo.com/my3d.gltf#pos=1,0,0&prio=-5&t=0,100
2023-09-01 14:20:02 +02:00
2023-09-04 21:20:59 +02:00
+=============================+=================================+
| Demo | Explanation |
+=============================+=================================+
| pos=1,2,3 | vector/coordinate argument e.g. |
+-----------------------------+---------------------------------+
| pos=1,2,3&rot=0,90,0&q=.foo | combinators |
+-----------------------------+---------------------------------+
2023-09-01 14:20:02 +02:00
2023-09-04 21:20:59 +02:00
Table 5
2023-09-02 21:44:57 +02:00
2023-09-04 21:20:59 +02:00
11. Security Considerations
2023-09-02 21:44:57 +02:00
2023-09-04 21:20:59 +02:00
Since XR Text contains metadata too, the user should be able to set
up tagging-rules, so the copy-paste feature can :
2023-09-02 21:44:57 +02:00
2023-09-04 21:20:59 +02:00
* filter out sensitive data when copy/pasting (XR text with
class:secret e.g.)
2023-09-02 21:44:57 +02:00
2023-09-04 21:20:59 +02:00
12. IANA Considerations
2023-09-02 21:44:57 +02:00
2023-09-04 21:20:59 +02:00
This document has no IANA actions.
2023-09-02 21:44:57 +02:00
2023-09-04 21:20:59 +02:00
13. Acknowledgments
2023-09-02 21:44:57 +02:00
2023-09-04 21:20:59 +02:00
TODO acknowledge.
2023-09-02 21:44:57 +02:00
2023-09-04 21:20:59 +02:00
van Kammen Expires 7 March 2024 [Page 15]