[x3d-public] V4.0 Open discussion/workshop on X3D HTML integration
Don Brutzman
brutzman at nps.edu
Tue Jun 14 09:31:51 PDT 2016
Thanks for your note Andreas.
On 6/6/2016 9:58 AM, Andreas Plesch wrote:
> Hi Don,
>
> On Sun, Jun 5, 2016 at 2:32 PM, Don Brutzman <brutzman at nps.edu <mailto:brutzman at nps.edu>> wrote:
>
>> Wondering if the x3dom dual-graph page dom structures align with the draft work on Shadow DOM at W3C.
>> https://www.w3.org/TR/shadow-dom
Interestingly the abstract for this working draft seems to indicate that they are defining a suggested best practice, not a required software API.
"Abstract. This specification describes a method of combining multiple DOM trees into one hierarchy and how these trees interact with each other within a document, thus enabling better composition of the DOM."
> The shaw-dom spec is being upstreamed to the dom spec.
>
> https://dom.spec.whatwg.org/
>
> This is a good resource, since it also explains the web page DOM in detail.
Yes. Of course whatwg is not the owner of the specification, but they have great engagement and are highly influential with W3C. Personally I've always thought that "Living Standard" is an oxymoron - how can you have stable interoperability if the so-called standard is allowed to change at any point? Better term is likely something like "Draft Recommendation" in this context. Whatever - they do good work, much of which eventually converges in the actual W3C Recommendations.
As you know, the W3C HTML5 Recommendation is the primary reference we need to align with for DOM interoperability.
HTML5: A vocabulary and associated APIs for HTML and XHTML
W3C Recommendation 28 October 2014
http://www.w3.org/TR/html5/
> I am not sure if the shaw-dom aligns with the dual graph approach because the shadow-dom is still a dom structure and not a scene graph. I think it may be still necessary to define a x3d dom and interfaces similar to https://developer.mozilla.org/en-US/docs/DOM/DOM_Reference#SVG_interfaces
Yes it is interesting. I'm pretty certain that these SVG-specific interfaces are in addition to the regular DOM interfaces - do you know where to confirm that?
The authoritative versions of SVG DOM are typically found as appendices in the SVG Recommendations themselves, along with definitions in IDL, Java and Ecmascript:
Scalable Vector Graphics (SVG) 1.1 (Second Edition)
W3C Recommendation 16 August 2011
https://www.w3.org/TR/SVG11/
Appendix B: SVG Document Object Model (DOM).
https://www.w3.org/TR/SVG11/svgdom.html
Scalable Vector Graphics (SVG) Tiny 1.2 Specification
W3C Recommendation 22 December 2008
Appendix A. The SVG Micro DOM (uDOM)
https://www.w3.org/TR/SVGTiny12/svgudom.html
Mobile SVG Profiles: SVG Tiny and SVG Basic
W3C Recommendation 14 January 2003, edited in place 15 June 2009
https://www.w3.org/TR/SVGMobile/
Appendix G. Mobile SVG DOM
https://www.w3.org/TR/SVGMobile/#sec-dom
Scalable Vector Graphics (SVG) 2
W3C Editor’s Draft 14 June 2016
https://svgwg.org/svg2-draft/
Appendix A: SVG Document Object Model (DOM)
https://svgwg.org/svg2-draft/svgdom.html
>> I'm hoping that John Carlson gets a chance to look at whether his JSON prototype expander might be adaptable as part of x3dom - that would be pretty valuable. Although Fraunhofer has outstanding prototype support in their Instant Reality engine, it has never been clear why that code can't simply be applied in x3dom as well. Certainly a consistent approach would seem to make both codebases more coherent and maintainable for them. If Fraunhofer refuses to adapt or release the Instant Reality prototype code then we will just have to do it ourselves... John's work seems like a big step in that direction
>
> Well, I would not have a good idea on how to implement prototypes in x3dom. Not sure if the Instant Reality code would really help. One idea may be to see if there is an existing declarative way to register new custom elements using web components, and extend that. But I do not think there is.
>
> https://www.w3.org/TR/custom-elements/
Here is the premise:
- X3DOM is written in JavaScript and can read X3D nodes.
- Prototype Expander is is written in JavaScript and can write X3D nodes.
- Prototype Expander could be a preprocessor for X3DOM scene loader.
>> Also thanks for pointing out important questions about Fraunhofer's stewardship of the X3DOM project. It will be good to learn more about their intentions so that our community can align effectively. There has been no handoff.
>
> Well, there have been no fixes or updates to the code base on github for a long time and a recent issue response suggested that FHG considers x3dom community supported.
Certainly there may be important roles for a few Consortium members to ensure that the working group's X3D version 4 efforts are being coherently implemented and integrated in both the X3DOM and Cobweb open-source codebases. "Implement and evaluate" is how we ensure any specification functionality actually works. Plenty of room for community participation too. 8)
>> Regarding the X3D event system: a changing value of any field in any node can be sent as an input to any field in any node, as long as types strictly match (apples to apples). Rephrased: a ROUTE passes a time-stamped value from one node to another. Internal to an X3D scene graph, that has been implemented dozens of times. Seems extremely simple.
>
>> External to an X3D scene graph, meaning via a browser using the Scene Access Interface (SAI), mechanisms are similarly well defined. Since the DOM is string based, and since any X3D event value can be expressed as a string, it seems like we have a straight connect-the-dots approach awaiting us. Forgive me for using a four-letter word, but if interested individuals might actually _read_ the HTML5/DOM and X3D specifications, then the answers to most implementation & alignment questions are likely spelled out for us.
>
> https://dom.spec.whatwg.org/#events would be HTML5 side of events.
>
> Is the statement at https://dom.spec.whatwg.org/#action-versus-occurance compatible with http://www.web3d.org/documents/specifications/19775-1/V3.3/Part01/concepts.html#Events ?
Seems like a part of the mix of information to explore...
>> It will be great to get our wiki organized for clarity and go-forward action on these important X3D version 4 design issues.
>
>> Thanks for letting us know about your other explanations - very interesting! 8)
>
> Yeah, VR is not really part of this discussion (although it could be a V4 topic) .
Mostly expecting that much of VR support is part of the Mixed and Augmented Reality (MAR) spectrum we are already exploring/supporting with ISO for X3D v4.1. Probably more is needed as well. Draft MAR Reference Model is online (for Web3D members) and will be a hot topic at Web3D Conference 2016 next month.
Mixed Augmented Reality (MAR)
http://www.web3d.org/working-groups/mixed-augmented-reality-mar
and
==========================================================
http://www.web3d.org/member/mixed-augmented-reality-mar-member-resources
Mixed Augmented Reality (MAR) Member Resources
Mixed and Augmented Reality (MAR) capabilities present computer-generated information within the real world, developing compatible extensions to X3D visualization and interactivity that implement an emerging ISO reference model.
This page includes some Web3D Member-Confidential resources for the Mixed Augmented Reality (MAR) Reference Model being produced by ISO/IEC JTC1/SC24 Working Group 9.
* N 3778 ISO-IEC CD2 18039.pdf
* Perey-MAR_RefModel_March_24_2015.pdf
* nwip_form-mar-fc-feb-20.pdf
* MAR-info-model.2016February21.pdf
==========================================================
>> Looking forward to continuing, sustainable evolution and progress together.
>
> I think if there is way to open spec. drafting more along the lines of other www spec. efforts on github, there is a chance to attract a wider community for more man power which would be much needed.
>
> Andreas
Yes good ideas. Web3D Consortium has always strived to find the right balance.
Good progress: Roy has been carefully adding each of the many X3D Specifications to Github, and group editing of new versions is underway. Access is limited to Web3D members who request it.
https://github.com/Web3DConsortium
Membership is open to all organizations and even individuals. Participation has benefits, modest fees are necessary to support this good work. The membership agreement also has strict rules regarding Intellectual Property Rights (IPR) that have successfully protected this entire body of work as a royalty-free public resource of great value.
http://www.web3d.org/participate
http://www.web3d.org/join
In every case for the many X3D specifications over the past two decades, community input and community review is included in our process. This is well recognized as fundamentally important - indeed essential for success.
Thanks for your insights and the great continuing discussion Andreas.
v/r Don
> On 6/3/2016 11:40 AM, Andreas Plesch wrote:
>
> Hi Roy, group,
>
> I would like to join the 2h open discussion on Wednesday but will be in an all day meeting, actually on the West Coast.
>
> These are excellent questions and trying to answer them will help getting closer.
>
> Here are some thoughts.
>
> The discussion on introducing an id field seemed to point towards the need to have fuller integration in the sense that it is difficult to isolate features. It may be necessary to define a x3d dom similar to the svg dom, with the corresponding interfaces. svg is very successful on the web but it took a long time to arrive there.
>
> x3dom has a dual graph approach. There is the x3d graph and in parallel the page dom graph which are kept in sync but are both fully populated. Johannes would know better how to explain the concept.
>
> It looks like FHG decided that x3dom is now considered community (only?) supported. This probably means it will be out of sync as newer web browsers arrive, or webgl is updated.
>
> I explored Aframe a bit more. It will be popular for VR. It is still in flux and evolves rapidly. The developers (mozilla) focus on its basic architecture (which is non-hierarchical, a composable component system) and expects users to use javascript to develop more advanced functionality (in the form of shareable components). So it is quite different, fun for developers, and for basic scenes easy for consumers. Since most mobile VR content at this point is basic (mostly video spheres and panos), it is a good solution for many.
>
> (As a test I also implemented indexedfaceset as an Aframe component, and it was pretty easy - after learning some Three.js. So it would be possible to have x3d geometry nodes on top of aframe. Protos, events and routes are another matter but also may not be impossible).
>
> There is still space for x3d as a more permanent, and optionally sophisticated 3d content format on the web.
>
> Event system: My limited understanding is that on a web page, the browser emits events when certain things happen. Custom events can also be emitted by js code (via DOM functions) for any purpose. (All ?) events have a time stamp and can have data attached. Then, events can be listened to. There is no restriction to listening, eg. all existing events are available to any listener. A listener then invokes a handler which does something related to the event. js code can consume, cancel, or relay events as needed (via DOM functions). It is not unusual that many events are managed on a web page. events can be used to guarantee that there is a sequence of processing.
>
> So how does the x3d event system relate ? There is a cascade, and directivity. How long does an event live ? one frame ? Until it fully cascaded through the scene graph ?
>
> Since x3dom and cobweb are currently the only options, from a practical stand point a question to ask may be this: what is needed to make x3dom and cobweb easy to use and interact with on a web page ? Typically, the web page would provide an UI, the connection to databases or other sources of data, and the x3d scene is responsible for rendering, and interacting with the 3d content. For VR, the UI would need to be in the scene, but connections and data sources would still be handled by the web page.
>
> Cobweb in effect allows use of the defined SAI functions. Is it possible to define a wrapper around these functions to allow a DOM like API (createElement, element.setAttribute .. element = null) ? It may be since they are similar anyways and it would go a long way. But it still would not be sufficient to let other js libraries such as D3.js or react control and modify a scene since they would expect x3d nodes to be real DOM elements.
>
> VR: A current issue is control devices. It would be probably useful to go over the spec. and see where there is an implicit assumption that mouse or keyboard input is available. VR HMDs have different controls (head position and orientation(pose), one button) and hand held controllers (gamepads, special sticks with their own position/orientations) or the tracked hands themselves become more popular. In VR, you do want to your hands in some way.
>
> Perhaps, it makes sense to have <Right/LeftHand/> nodes paralleling <Viewpoint/> with position/orientation fields which can be routed to transforms to manipulate objects ?
> How a browser would feed the <Hand> nodes would be up to the browser. InstantReality has a generic IOSensor.
>
> Andreas
>
>
> On Wed, Jun 1, 2016 at 4:53 PM, Roy Walmsley <roy.walmsley at ntlworld.com <mailto:roy.walmsley at ntlworld.com> <mailto:roy.walmsley at ntlworld.com <mailto:roy.walmsley at ntlworld.com>>> wrote:
>
> *X3D HTML integration____*
>
> *__ __*
>
> *X3D V4.0 Open discussion/workshop____*
>
> *__ __*
>
> *June 8^st 2016 at 1500-1700 UTC (0800-1000 PDT, 1500-1700 GMT, 1700-1900 CET)____*
>
> *__ __*
>
> A discussion/workshop on version 4.0 of X3D which aims to consider the following questions, and suggest potential solutions.____
>
> __ __
>
> __· __What level of X3D integration into HTML5 do we want?____
>
> __o __Do we want to be fully integrated like SVG?____
>
> __· __Do we want/need a DOM spec? If so:____
>
> __o __Which DOM version should it be based on?____
>
> __o __Do we want to fully support all DOM/HTML features?____
>
> __· __Do we want to maximize the backwards compatibility of V4.0 with V3.3? Or break away completely?____
>
> __o __Do we want to retain SAI?____
>
> __· __What features do we want? For example,____
>
> __o __How is animation to be handled? The X3D way of TimeSensor and ROUTEs, or an HTML way, such as CSS3 animations, or else JavaScript?____
>
> __o __How is user interaction to be handled? The X3D way of Sensors, or the HTML way with event handlers?____
>
> __o __Do we need any different nodes? One example might be a mesh node?____
>
> __o __Do we want Scripts and Prototypes in HTML5?____
>
> __o __How do we want to handle styling?____
>
> __· __What profile(s) do we need for HTML?____
>
> __ __
>
> The discussion/workshop will be held on the Web3D teleconference line. It is open to anyone interested in X3D. Please e-mail roy.walmsley at ntlworld.com <mailto:roy.walmsley at ntlworld.com> <mailto:roy.walmsley at ntlworld.com <mailto:roy.walmsley at ntlworld.com>> or brutzman at nps.edu <mailto:brutzman at nps.edu> <mailto:brutzman at nps.edu <mailto:brutzman at nps.edu>> for teleconference details.____
>
> __ __
>
> If you can’t join in the discussion, but would still like to contribute to the debate, your comments would be welcomed on the X3D public mailing list at x3d-public at web3d.org <mailto:x3d-public at web3d.org> <mailto:x3d-public at web3d.org <mailto:x3d-public at web3d.org>>.____
>
> __ __
>
> Roy Walmsley____
>
> X3D WG Co-chair____
>
> __ __
>
[...]
> --
> Andreas Plesch
> 39 Barbara Rd.
> Waltham, MA 02453
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
More information about the x3d-public
mailing list