<!DOCTYPE html> <html> <head> <title>XR Macros</title> <meta name="GENERATOR" content="github.com/mmarkdown/mmark Mmark Markdown Processor - mmark.miek.nl"> <meta charset="utf-8"> </head> <body> <!-- for annotated version see: https://raw.githubusercontent.com/ietf-tools/rfcxml-templates-and-schemas/main/draft-rfcxml-general-template-annotated-00.xml --> <style type="text/css"> body{ font-family: monospace; max-width: 1000px; font-size: 15px; padding: 0% 20%; line-height: 30px; color:#555; background:#F0F0F3 } h1 { margin-top:40px; } pre{ line-height:18px; } a,a:visited,a:active{ color: #70f; } code{ border: 1px solid #AAA; border-radius: 3px; padding: 0px 5px 2px 5px; } pre{ line-height: 18px; overflow: auto; padding: 12px; } pre + code { background:#DDD; } pre>code{ border:none; border-radius:0px; padding:0; } blockquote{ padding-left: 30px; margin: 0; border-left: 5px solid #CCC; } th { border-bottom: 1px solid #000; text-align: left; padding-right:45px; padding-left:7px; background: #DDD; } td { border-bottom: 1px solid #CCC; font-size:13px; } </style> <br> <h1>XR Macros</h1> <br> <pre> stream: IETF area: Internet status: informational author: Leon van Kammen date: 2023-04-12T00:00:00Z workgroup: Internet Engineering Task Force value: draft-XRMACROS-leonvankammen-00 </pre> <h1 class="special" id="abstract">Abstract</h1> <p>This draft offers a specification for embedding macros in existing 3D scenes/assets, to offer simple interactions and configure the renderer further.<br> Together with URI Fragments, it allows for rich immersive experiences without the need of a complicated sandboxed scripting languages.</p> <blockquote> <p>Almost every idea in this document is demonstrated at <a href="https://xrfragment.org">https://xrfragment.org</a>, as this spec was created during the <a href="https://xrfragment.org">XR Fragments</a> spec.</p> </blockquote> <section data-matter="main"> <h1 id="introduction">Introduction</h1> <p>How can we add more features to existing text & 3D scenes, without introducing new dataformats?<br> Historically, there’s many attempts to create the ultimate markuplanguage or 3D fileformat.<br> Their lowest common denominator is: (co)authoring using plain text.<br> Therefore, XR Macros allows us to enrich/connect existing dataformats, by offering a polyglot notation based on existing notations:<br></p> <ol> <li>getting/setting common used 3D properties using querystring- or JSON-notation</li> <li>targeting 3D properties using the lightweight query notation present in <a href="https://xrfragment.org">XR Fragments</a></li> </ol> <blockquote> <p>NOTE: The chapters in this document are ordered from highlevel to lowlevel (technical) as much as possible</p> </blockquote> <h1 id="core-principle">Core principle</h1> <ol> <li>XR Macros use querystrings, but are HTML-agnostic (though pseudo-XR Fragment browsers <strong>can</strong> be implemented on top of HTML/Javascript).</li> <li>An XR Macro is 3D metadata which starts with ‘!’ (<code>!clickme: fog=0,10</code> e.g.)</li> <li>Metadata-values can contain the <code>|</code> symbol to 🎲 roundrobin variable values (<code>!toggleme: fog=0,10|fog=0,1000</code> e.g.)</li> <li>XR Macros acts as simple eventhandlers for URI Fragments: they are automatically published on the (<a href="https://xrfragment.org">XR Fragments</a>) hashbus, to act as events (so more serious scripting languages can react to them as well).</li> <li>XR Macros can assign object metadata (<code>!setlocal: foo=1</code> writes <code>foo:1</code> metadata to the object containing the <code>!setlocal</code> metadata)</li> <li>XR Macros can assign global metadata (<code>!setfoo: #foo=1</code> writes <code>foo:1</code> metadata to the root scene-node)</li> </ol> <blockquote> <p>These very simple principles allow for rich interactions and dynamic querying</p> </blockquote> <h1 id="conventions-and-definitions">Conventions and Definitions</h1> <p>See appendix below in case certain terms are not clear.</p> <h1 id="list-of-xr-macros">List of XR Macros</h1> <p>(XR) Macros can be embedded in 3D assets/scenes.<br> Macros enrich existing spatial content with a lowcode, limited logic-layer, by recursive (economic) use of the querystring syntax (which search engines and <a href="https://xrfragment.org">XR Fragments</a> already uses.<br> This is done by allowing string/integer variables, and the <code>|</code> symbol to roundrobin variable values.<br> Macros also act as events, so more serious scripting languages can react to them as well.<br></p> <table> <thead> <tr> <th>key</th> <th>type</th> <th>example (JSON)</th> <th>function</th> <th>existing compatibility</th> </tr> </thead> <tbody> <tr> <td><code>@bg</code></td> <td>string</td> <td><code>"@bg":"#cube"</code></td> <td>bg: binds fog near/far based to cube x/y/z (anim) values</td> <td>custom property in 3D fileformats</td> </tr> <tr> <td><code>@fog</code></td> <td>string</td> <td><code>"@fog":"#cube"</code></td> <td>fog: binds fog near/far based to cube x/y (anim) values</td> <td>custom property in 3D fileformats</td> </tr> <tr> <td><code>@scroll</code></td> <td>string</td> <td><code>"@scroll":"#cube"</code></td> <td>texturescrolling: binds texture x/y/rot based to cube x/y/z (anim) values</td> <td>custom property in 3D fileformats</td> </tr> <tr> <td><code>@emissive</code></td> <td>string</td> <td><code>"@emissive":"#cube"</code></td> <td>day/night/mood: binds material’s emissive value to cube x/y/z (anim) values</td> <td>custom property in 3D fileformats</td> </tr> </tbody> </table> <h2 id="usecase-click-object">Usecase: click object</h2> <table> <thead> <tr> <th>custom property</th> <th>value</th> <th>trigger when</th> </tr> </thead> <tbody> <tr> <td>!clickme</td> <td>bg=1,1,1&foo=2</td> <td>object clicked</td> </tr> </tbody> </table> <h2 id="usecase-conditional-click-object">Usecase: conditional click object</h2> <table> <thead> <tr> <th>custom property</th> <th>value</th> <th>trigger when</th> </tr> </thead> <tbody> <tr> <td>#</td> <td>foo=1</td> <td>scene</td> </tr> <tr> <td>!clickme</td> <td>q=foo>2&bg=1,1,1</td> <td>object clicked and foo > 2</td> </tr> </tbody> </table> <blockquote> <p>when a user clicks an object with the custom properties above, it should set the backgroundcolor to <code>1,1,1</code> when <code>foo</code> is greater than <code>2</code> (see previous example)</p> </blockquote> <h2 id="usecase-click-object-roundrobin">Usecase: click object (roundrobin)</h2> <table> <thead> <tr> <th>custom property</th> <th>value</th> <th>trigger when</th> </tr> </thead> <tbody> <tr> <td>!cycleme</td> <td>day|noon|night</td> <td>object clicked</td> </tr> <tr> <td>day</td> <td>bg=1,1,1</td> <td>roundrobin</td> </tr> <tr> <td>noon</td> <td>bg=0.5,0.5,0.5</td> <td>roundrobin</td> </tr> <tr> <td>night</td> <td>bg=0,0,0&foo=2</td> <td>roundrobin</td> </tr> </tbody> </table> <blockquote> <p>when a user clicks an object with the custom properties above, it should trigger either <code>day</code> <code>noon</code> or <code>night</code> in roundrobin fashion.</p> </blockquote> <h2 id="usecase-click-object-or-uri-fragment-and-scene-load-trigger">Usecase: click object or URI fragment, and scene load trigger</h2> <table> <thead> <tr> <th>custom property</th> <th>value</th> <th>trigger when</th> </tr> </thead> <tbody> <tr> <td>#</td> <td>random</td> <td>scene loaded</td> </tr> <tr> <td>#random</td> <td>random</td> <td>URL contains #random</td> </tr> <tr> <td>!random</td> <td>day|noon|night</td> <td>#random, # or click</td> </tr> <tr> <td>day</td> <td>bg=1,1,1</td> <td>roundrobin</td> </tr> <tr> <td>noon</td> <td>bg=0.5,0.5,0.5</td> <td>roundrobin</td> </tr> <tr> <td>night</td> <td>bg=0,0,0&foo=2</td> <td>roundrobin</td> </tr> </tbody> </table> <h2 id="usecase-present-context-menu-with-options">Usecase: present context menu with options</h2> <table> <thead> <tr> <th>custom property</th> <th>value</th> <th>trigger when</th> </tr> </thead> <tbody> <tr> <td>!random</td> <td>!day</td> <td>!noon</td> </tr> <tr> <td>!day</td> <td>bg=1,1,1</td> <td>clicked in contextmenu</td> </tr> <tr> <td>!noon</td> <td>bg=0.5,0.5,0.5</td> <td>clicked in contextmenu</td> </tr> <tr> <td>!night</td> <td>bg=0,0,0&foo=2</td> <td>clicked in contextmenu</td> </tr> </tbody> </table> <blockquote> <p>When interacting with an object with more than one <code>!</code>-macro, the XR Browser should offer a contextmenu to execute a macro.</p> </blockquote> <p>In a similar way, when <strong>any</strong> <code>!</code>-macro is present on the sceneroot, the XR Browser should offer a context-menu to execute those macro’s.</p> <h2 id="event-bubble-flow">Event Bubble-flow</h2> <p>click object with (<code>!clickme</code>:<code>AR</code> or <code>!clickme</code>: <code>!reset</code> e.g.)</p> <pre><code> â—» │ └── does current object contain this property-key (`AR` or `!reset` e.g.)? └── no: is there any (root)object containing property `AR` └── yes: evaluate its (roundrobin) XR macro-value(s) (and exit) └── no: trigger URL: #AR </code></pre> <p>click object with (<code>!clickme</code>:<code>#AR|#VR</code> e.g.)</p> <pre><code> â—» │ └── apply the roundrobin (rotate the options, value `#AR` becomes `#VR` upon next click) └── is there any object with property-key (`#AR` e.g.)? └── no: just update the URL to `#AR` └── yes: apply its value to the scene, and update the URL to `#AR` click object with (`!clickme`:`!foo|!bar|!flop` e.g.) </code></pre> <p>â—» │<br> └── apply the roundrobin (rotate the options, value <code>!foo</code> becomes <code>!bar</code> upon next click) └── is there any object with property-key (<code>!foo</code> e.g.)? └── no: do nothing └── yes: apply its value to the scene “`</p> <blockquote> <p>Note that only macro’s can trigger roundrobin values or contextmenu’s, as well as roundrobin values never ending up in the toplevel URL.</p> </blockquote> <h1 id="security-considerations">Security Considerations</h1> <h1 id="iana-considerations">IANA Considerations</h1> <p>This document has no IANA actions.</p> <h1 id="acknowledgments">Acknowledgments</h1> <ul> <li><a href="https://nlnet.nl">NLNET</a></li> <li><a href="https://futureoftext.org">Future of Text</a></li> <li><a href="https://visual-meta.info">visual-meta.info</a></li> </ul> <h1 id="appendix-definitions">Appendix: Definitions</h1> <table> <thead> <tr> <th>definition</th> <th>explanation</th> </tr> </thead> <tbody> <tr> <td>scene</td> <td>a (local/remote) 3D scene or 3D file (index.gltf e.g.)</td> </tr> <tr> <td>3D object</td> <td>an object inside a scene characterized by vertex-, face- and customproperty data.</td> </tr> <tr> <td>XR fragments</td> <td>URI Fragment with spatial hints like <code>#pos=0,0,0&t=1,100</code> e.g.</td> </tr> <tr> <td>query</td> <td>an URI Fragment-operator which queries object(s) from a scene like <code>#q=cube</code></td> </tr> <tr> <td>FPS</td> <td>frames per second in spatial experiences (games,VR,AR e.g.), should be as high as possible</td> </tr> <tr> <td><code>â—»</code></td> <td>ascii representation of an 3D object/mesh</td> </tr> <tr> <td>(un)obtrusive</td> <td>obtrusive: wrapping human text/thought in XML/HTML/JSON obfuscates human text into a salad of machine-symbols and words</td> </tr> </tbody> </table> </section> </body> </html>