Internet Internet Engineering Task Force 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 interactive text across for (XR) Browsers. XR Fragments allows us to enrich existing dataformats, by recursive use of existing technologies like URI Fragments & visual-meta.

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. However, thru the lens of authorina,g their lowest common denominator is still: plain text. XR Fragments allows us to enrich existing dataformats, by recursive use of existing technologies:

• addressibility & navigation of 3D objects: URI Fragments + (src/href) metadata
• addressibility & navigation of text objects: visual-meta

Conventions and Definitions

• 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 defined in 3D Scene or Object(nodes)
• XR fragment: URI Fragment with spatial hints (#pos=0,0,0&t=1,100 e.g.)
• src: a (HTML-piggybacked) metadata-attribute of a 3D object which instances content
• href: a (HTML-piggybacked) metadata-attribute of a 3D object which links to content
• query: an URI Fragment-operator which queries object(s) from a scene (#q=cube)

{::boilerplate bcp14-tagged}

Navigating 3D Here's an ascii representation of a 3D scene-graph which contains 3D objects (◻) and their metadata: index.gltf │ ├── ◻ buttonA │ └ href: #pos=1,0,1&t=100,200 │ └── ◻ buttonB └ href: other.fbx An XR Fragment-compatible browser viewing this scene, allows the end-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).

Navigating text TODO

Embedding 3D content Here's an ascii representation of a 3D scene-graph with 3D objects (◻) which embeds remote & local 3D objects (◻) (without) using queries: +------------------------------------------------------------+ +---------------------------+ | | | | | index.gltf | | rescue.com/aquarium.gltf | | │ | | │ | | ├── ◻ canvas | | └── ◻ fishbowl | | │ └ src: painting.png | | ├─ ◻ bassfish | | │ | | └─ ◻ tuna | | ├── ◻ aquariumcube | | | | │ └ src: ://rescue.com/fish.gltf#q=bassfish%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 rescue.com/aquarium.gltf, only the queried objects bassfish and tuna will be instanced inside aquariumcube. Resizing will be happen accordingly to its placeholder object (aquariumcube), see chapter Scaling.

Embedding text

List of XR URI Fragments

Security Considerations TODO Security

IANA Considerations This document has no IANA actions.

Acknowledgments TODO acknowledge.