X3D JSON Encoding
Preliminary notes on the creation of an X3D JSON encoding.
- This page is to understand the conversion process so that a high-quality encoding definition can be created
- Don Brutzman started a thread on the X3D-Public list.
Primary design criterion: round-trippable lossless representation of X3D scene.
Conversion approach of greatest practical interest: XML to/from JSON. Issues:
- How to convert attribute names to distinguish them from child elements
- JSON handling of container elements to preserve parent/child relationships, distinguishing child elements from attributes
- Creation of JSON elements with datatypes appropriate to content (e.g., integer, float, strings, etc.)
- Both X3D and JSON can include comments, and so need an option for inclusion (by default) or removal (optional) of comments in order to ensure 100% round-trip conversion capabilities.
- Support for singleton (self-closing) XML tags also needs to be considered
- Inclusion and preservation of embedded XML namespace information in an XML (.x3d) document
- Are there any use cases that might modify how X3D is represented in JSON?
- If so, it would be good to spell them out and understand them well.
- We want conversion rules to permit implementations that can achieve user goals.
Here are suggested discussion points for the X3D teleconference and future followups.
- Can a file reader distinguish the incoming encodings (.x3d .x3dv .x3db .x3de .json) independent of file extension or MIME media type?
- Is there a good/consistent way for X3DOM to utilize such capabilities?
- Is there a single authoritative reference for JSON itself? and for JSON-XML conversions?
- Yes. See  for the JSON Data Interchange Format
- Compare compression size and decompression speed of a TestMesh.x3d.json.gz to TestMesh.x3db and TestMesh.x3d.exi (EXI will likely win because it includes data typing)
- Once a canonical form for X3D as JSON is established, add conversion capabilities to X3D-Edit and also autoconvert, test and publish JSON for all of the 3800+ scenes in the X3D Examples Archives
- Decide if this capability needs to be defined in one of the X3D standards, or perhaps as an X3D best practice.
- Probably lots more... What else?
- LD - Leonard Daly
- DPB - Don Brutzman
- XML to JSON Converter (provides option to assign a prefix to JSON attributes, default is @ character) 
- Apache Camel, XML JSON Data Format (camel-xmljson) 
- JSON Definition 
- JSON Data Interchange Format 
- JSON Markup Language (JsonML) 
- XSLTJSON: Transforming XML to JSON using XSLT 
- Converting Between XML and JSON 
- XML/JSON Perl Converter 
- IBM's PHP converter 
- Java Converter 
- Google Code Library