[x3d-public] Minutes of X3D WG Meeting Wednesday 18th October 2017 [Public Release]

Tue Oct 31 11:34:24 PDT 2017

Minutes of the X3D WG meeting held on Wednesday 18th October 2017  - Public
Release

Attendees: Roy Walmsley, Dick Puk, Leonard Daly, Don Brutzman

Apologies received: None

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A. Outstanding matters

                None.

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B. Summary and Technical reports

Opportunity for anyone to make a short report on Web site, marketing,
communication, specification or technical matters that is not already on the
Agenda.

1.	Report on Mantis SG meeting held Thursday 12th October 2017

Reference:
http://web3d.org/mailman/private/x3d_web3d.org/2017-October/006418.html

Roy reported that seven Mantis issues were reviewed. Four were agreed and
updated to Assigned. Three needed further discussion and were updated to
Acknowledged.

2.	Report on Mantis SG meeting held Monday 16th October 2017

Reference:
http://web3d.org/mailman/private/x3d_web3d.org/2017-October/006424.html

Roy reported that eight Mantis issues were reviewed. Six issues were agreed
and updated to Assigned. One needed further discussion and was updated to
Acknowledged. The other needs feedback which will be requested via the
public list.

Roy reported that the subgroup had also discussed ISO edition numbers, and
considered whether to add these to the standards table, at
http://www.web3d.org/standards. In so doing they noted that there were
inconsistencies in the 'Names' column in the table that should be corrected.
For example, two incorrectly had "IS", and only one, H-Anim, had a
descriptive name.

The structure of the table was reviewed, and proposals for improvements put
forward. One proposal was to rename the columns, changing "Name" to "ISO
Identifier", and "Common Name" to "Title". Another proposal was to modify
the links, changing the link on what is currently the "Common Name" to be
the link to the HTML document, as readers are likely to click on that in the
first instance. The current link of the "Common Name" to the properties page
would then be added separately. It was also noted that the H-Anim standard
19774 appears in both tables. Furthermore, neither table has a title. It was
agreed that the title of the first table should be "X3D standards", and the
title of the second should be "Other standards", with the H-Anim standard
being removed from the first table.

It was also proposed that a paragraph should be added noting that the links
in the tables are to the Web3D copyrighted versions, and if readers wanted
the ISO copyrighted versions to links to both the ISO store page
(https://www.iso.org/store.html) and ISO publicly available standards page
(http://standards.iso.org/ittf/PubliclyAvailableStandards/index.html).

[Co-chair note: I noted, for example, that the ISO/IEC 19775-1:2013 ISO
store page at https://www.iso.org/standard/60760.html lists this standard as
costing 158 CHF, with no mention that it is included on the ISO publicly
available standards page.]

3.	Report on H-Anim V2.0 CD2 standards progress

Member-only material

4.	Report on draft C/C++/C# language binding standards progress

Member-only material

5.	Automatic X3DOM building from Pull Requests

Member-only material

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C. Discussion Topics

1.	X3D integration into HTML5/DOM - Events and Event models

Reference: http://www.web3d.org/member/wiki/x3dhtml-integration-event-models

Reference:
http://www.web3d.org/wiki/index.php/X3D_V4_HTML_Integration_Requirements

Reference: http://www.web3d.org/member/wiki/x3d-v4-events

Leonard summarized the structure of X3D events and HTML events. X3D events
incorporate a data package, which can be small or large, and a time stamp,
this latter as an ID, rather than actual time. HTML  events are an object
structure, including the source and target, event phase, whether bubbling,
etc, as well as the data. HTML data packages tend to be limited in scope,
most often passing data by reference.. In addition, HTML events have a user
definable component.

HTML has many specific event types, for example, mouse down, key down,
scroll, etc. HTML also defines custom  events. HTML has two phases for event
handling. One is immediate handling of the event, prior to standard
handling, when an event bubbles up through the tree looking for a handler.

In summary, the two systems may not be completely incompatible, but they are
not obviously compatible.

Roy asked what we want to do? For example, do we want to maintain backwards
compatibility? Can we think in terms of DOM events affect the DOM, and X3D
events affect X3D? How is event handling related to the rendering cycle?

Considering that we consider that within an HTML browser there will be both
a DOM tree and an X3D scene graph in parallel, changes to DOM have to be
passed to the scene graph, and changes to the scene graph have to be passed
to the DOM. 

In HTML there is a call RequestAnimationFrame (see
https://www.w3.org/TR/html/webappapis.html#animation-frames, and
https://developer.mozilla.org/en-US/docs/Web/API/window/requestAnimationFram
e) that is made when the browser indicates that animations, etc. should be
updated before the next rendering cycle. Leonard noted that any code
executed from this call has very little time to run. For example, to
maintain the desired frame rate of 90 Hz for VR, any code execution during
this call probably has less than 10 milliseconds.

HTML 5.1 2nd Edition specification at https://www.w3.org/TR/html/ was
reviewed, and in particular the sub clauses at 7.1.4 Event loops noted
(https://www.w3.org/TR/html/webappapis.html#event-loops). Then sub clause
7.1.1 Introduction, within 7.1 Scripting, was noted
(https://www.w3.org/TR/html/webappapis.html#scripting-introduction), and in
particular the fourth bullet point. These bullet points list mechanisms that
can cause author-provided executable code to run. The fourth bullet point
describes "Processing of technologies like SVG that have their own scripting
features". X3D would fit into that category. Leonard noted, however, that
SVG scripts can access both DOM and SVG elements.

For the two implementations Leonard reported that X3DOM does not have the
standard HTML event handler mechanisms, as the code is too old. The
situation with X_ITE was unknown.

It was agreed that for X3D/HTML integration the use of HTML event handlers,
that content authors are familiar with should be permitted. Also, it might
be helpful to use terminology to differentiate HTML authors from 3D
modelling authors.

The discussion concluded with consideration of the next steps. These were
agreed to be review of the two implementations X3DOM  and X_ITE, and review
of examples. These examples might include the "Rosetta stone" examples
previously presented that looked at X3D/HTML/SVG integration into a single
web page (see
http://www.web3d.org/member/wiki/x3dhtml-integration-dom-elements).

2.	Review of Wikipedia pages

X3D - Reference: https://en.wikipedia.org/wiki/X3D

Web3D Consortium - Reference: https://en.wikipedia.org/wiki/Web3D_Consortium

Not discussed.

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D. Specification work, GitHub, and Mantis issues

1.	Mantis issue 1151 : 19775-1, 9.4.2 Inline - Inline is silent about
head, component, unit, and meta statements

Reference: http://www.web3d.org/member-only/mantis/view.php?id=1151

Not discussed.

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E. Schedule review

Other topics for discussion not yet assigned are:

Investigate CSS with respect to 3D display capabilities.

October 25th -

Note: Daylight saving time ends for the UK and Europe on Sunday 29th
October, therefore the meeting on November 1st will be one hour earlier for
Europeans.

November 1st -  C/C++/C# Language Bindings Review

Note: Daylight saving time ends for US on Sunday 5th November, so the
meeting times will revert back to normal for Europeans.

November 8th -

November 16th - 

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Roy Walmsley

X3D WG co-chair

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