[X3D-Public] [x3dom-developers] x3d to json experiments & links of interest

Don Brutzman brutzman at nps.edu
Sun Jul 13 08:46:16 PDT 2014

Thanks for all the discussion.  Lots of interesting design possibilities - cool!

Everyone's points make it clear that we should carefully define a recommended encoding so that X3D JSON can be widely supported and reusable using various libraries and tools.  Formalizing the encoding patterns will let us find the best balance among the design factors.  Of course round-trip convertibility to other encodings (usually via .x3d) is paramount.

Our team at NPS plans to look at comparisons of scene.json.gz to scene.json-to-x3d.exi examples to see which compresses best.

Regarding implicit XML containerField values for field names, or going explicit in field names (aka "wrapper tag"), past comparisons for the XML encoding .x3d can be found in the following essay.  I don't think these points mean that we will land on the same approach, but they are offered as a list of points that can be considered and improved as appropriate.

	Wrapper Tags Considered Harmful

Closely related topic:  how to represent node prototype declarations and instances.

X3D JSON Encoding is now included on the list of X3D v3.4 improvements that the working group is considering.  As with all v3.4 extensions to X3D, we expect that any additions will be able to match X3D v3.x forward compatibility with X3D v4/X3DOM/HTML5 approaches.


Not totally clear yet where the completed specification efforts will land - the working group will examine the document tradeoffs.  From what I've heard, most likely is that it will either be included as part of

	ISO/IEC 19777-1, X3D language bindings: ECMAScript

or possibly we will be creating new ISO standards documents, e.g.  something like

	ISO/IEC 19776-4 X3D Efficient Binary Encoding (.x3de perhaps)

	ISO/IEC 19776-5 X3D JSON Encoding

This area of work will be an agenda topic at our upcoming open workshop preceding the Web3D Conference:

	Friday August 8, Vancouver Canada

For reference, this email thread can be found at


Looking forward to continued insights, discussion and progress together.

all the best, Don
Don Brutzman  Naval Postgraduate School, Code USW/Br       brutzman at nps.edu
Watkins 270,  MOVES Institute, Monterey CA 93943-5000 USA   +1.831.656.2149
X3D graphics, virtual worlds, navy robotics http://faculty.nps.edu/brutzman

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