[x3d-public] X3D working group minutes, 9 JAN 2020: recent events, X3Dv4 progress, name restrictions, hidden field, Mantis issue resolution

Don Brutzman brutzman at nps.edu
Sat Jan 11 17:13:51 PST 2020

Agenda: ongoing review of progress and issues list for X3Dv4.

Attendees: Anita Havele, Vince Marchetti, Nicholas Polys, Dick Puk, Don Brutzman.

Afterwards Dick and I continued our weekly reviews with Michalis on draft specification for X3D PBR.


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0. *Agenda check*

Welcome everyone, we are well on our way to finish X3Dv4.  8)

Previous minutes:

* [x3d-public] X3D Working Group minutes 3 JAN 2020: X3Dv4 progress; PointProperties and points/lines/mesh, OBJ

Discussion, with focus on new and recent implementation efforts:


0.a. Excellent call with _IEEE 3D Body Processing Working Group_ participants yesterday.  Summary:

- Great liaison discussion!  They are expert and very competent with demonstrated industry use cases.
- Focus: general capabilities, metadata schemes, andmodel security via inline permissions and encryption/authentication.
- Next member-only meeting 30 JAN.  Further participation encouraged - Web3D membership has value!


0.b. X3D XML Schema/DOCTYPE/Schematron and example updates

	X3D Specifications: Schema and DOCTYPE Validation

I found several validation problems that had not been isolated before.  Now detected and (where possible) fixed by X3D-Tidy and X3D Schematron.

X3D XML Schema update activity:

11 JAN 2020, brutzman
- added containerFieldChoicesX3DCoordinateNode and containerFieldChoicesX3DNormalNode
   also (v4.0) adding new HAnim v2 skinBinding fields for HAnimHumanoid
- remove mistaken inclusion of HAnimMotion under HAnimJoint
- (v3.0-3.3) HAnimHumanoid only includes 1 Coordinate, 1 Normal (skinCoord, skinNormal)
- (v4.0)     HAnimHumanoid  now includes 2 Coordinate, 2 Normal (skinCoord/SkinBindingCoords,
- TODO add hidden field to X3DGroupingNode nodes
- TODO PointProperties inconsistent camel-case spelling, should be lineType and lineWidthScaleFactor: Mantis 1252

0.c. Website

Expect to have new X3Dv4 banner and/or menus on web3D.org next week, will review on Wednesday communications-team call.

Bug report posted:
Needed: "V4.0" as menu-time choice for
	Version (X3D Specifications only) *

TODO: we will begin listing *X3Dv4 Assets* on X3D Implementations page. For example:

	full:	X3D XML Schema, Doctype, Schematron, Tooltips, X3D0-Tidy,
		X3D Examples validation, X3DUOM, X3D Java, X3D Python, X3D Ontology
	partial: X3DOM, X_ITE, view3dscene (see table)
	maybe:	FreeWrl, X3DJSONLD JavaScript
	coming:	X3D-Edit


0.d. Web3D 2020 Conference status

- Teleconferences every 1-2 weeks
- Working on website recovery, temporary site https://web3d.or.kr
- Web3D announcement site
- Working on ACM TMRF for submission next week

- Expected paper, session proposal deadline: 20 FEB 2020
- VR Hackathon, 21-23 June 2020 (tentative)
- Conference 24-26 June 2020


1. *X3Dv4 Progress Review*

Major pieces of work in progress and highly mature include:

a. glTF lighting and physically based rendering, Michalis Kamburelis

b. X3D Sound Component and HTML Audio, Athanasios Malamos and Efi Lakka

c. Projective Texture Mapping (PTM), Kwan Hee Yoo

d. Many specification improvements and additions.

Key references:

[1] X3D Version 4 Overview

[2] X3Dv4 Highlights

[3] X3Dv4 Implementations Status

[4] Draft X3Dv4 specification from SIGGRAPH, August 2019

[5] Mantis Issue Tracker (requires 2 sets of member login)

You can quickly see all X3Dv4 issues (with tag V4.0) by selecting the filter "X3Dv4" within mantis.

As specified in the reference pages, our next steps of implement/evaluate over the next quarter include
- finished specification prose in github,
- addressing all mantis issues,
- proper example X3D models available for each node/field,
- validation tools confirming examples are satisfactory,
- two or more implementations (X3DOM and X_ITE, others),
- consensus by working group, approval by Web3D Consortium, submission to ISO.

Here are refined milestones from X3Dv4 Implementations Status page:

_Milestones Timeline_

* /26-31 July 2019/.    Publish draft specification plus examples and implementation updates at Web3D2019/SIGGRAPH 2019 conferences.
* /16 December 2019/.   Working group accepts X3Dv4 new-technology submissions, with rich capability set publicized for implementation work.
* /31 January 2020/.    Specification Editors provide ISO Working Draft on github for use and confirmation by Web3D Consortium members.
* /First quarter 2020/. Implement new components in X3D players, evaluate scene examples for conformance. Publish weekly progress updates.
* /When completed/.     Completed ISO Working Draft submitted to X3D Community, Web3D Consortium members, Web3D Board of Directors.
* /BoD approval/.       Working Draft upgraded to Committee Draft and submitted with NWIP to ISO.
* /Sequential updates/. Specification updates for 19775-2 Scene Access Interface (SAI), file encodings (XML, ClassicVRML, JSON etc.) and language bindings (JavaScript, Java, Python), and X3D Semantic Web (possibly 19775-3).


2. *IPR statements* - still pending, Anita is communicating with each individual involved.

Goal completion by end of January.

Terms of membership and a requirement for contributing technology is to sign the Web3D Intellectual Property Rights (IPR) Policy asserting that no known patented technology subject to licensing is being submitted.


Web3D Executive Director Anita Havele has checked past records.  Since many of these were signed years ago, we simply plan to ask everyone contributing to X3Dv4 specification to again assert that they are following the IPR policy.


3. *Web3DUX Working Group Proposal*

Goal completion next week, hopefully.

Thanks for all review of Web3DUX Working Group Proposal and draft Charter.  Dr. Feng Liu and Dr. Amela Sadagic have submitted to Web3D Board of Directors, feedback from Board of Directors review has been provided, public website and announcement is expected soon.

[5] [x3d-public] 27 NOV 2019 - Web3DUX working group meeting minutes and Web3DUX working group proposal review


4. *December Events* include much tremendous outreach!  Here they are again:

[6] Semantic Web Pro (SemWeb.Pro)

[7] IITSEC 2019 Tutorial Distributed Interactive Simulation (DIS) 101

[8] Collaborative 3D Visualization for Ashore, Afloat and Expeditionary Readiness Workshop

Have appended Web3D presentation tweet and then all tweets finished.  Outcomes message being sent to participants.

	Anita Havele, Executive Director and Dr. Nicholas Polys, President.
	Web3D Consortium offers a tremendous Value Proposition:
	Enabling Enterprise Connectedness and Real-Time Networked Communications via ISO Standards.
	Check the interoperability timeline!

	Membership and participation has impact!
	Anita Havele, Executive Director and Dr. Nicholas Polys, President.
	Web3D Consortium offers a tremendous Value Proposition:
	Enabling Enterprise Connectedness and Real-Time Networked Communications via ISO Standards.

Planning on summary announcement for all these events on Web3D home page by next week.


5. *Mantis Issues*

We have 78 issues tagged as X3Dv4.0.  Current issues list attached last week.

Our primary work is reviewing the list and addressing issues.

* Mantis Definitions

* Mantis Workflows


Priority: issues that affect schemas, validation and examples.

5.a. Mantis 1271: add hidden field to Shape

- More sensible from a modeling perspective: put it on any X3DGroupingNode.
   10.3.2 X3DGroupingNode
- Note that 'hidden' only relates to visual display, not behavior animation.
- Add to X3Dv4 specification, review prose next week
- Update X3D schemas and X3DUOM to support implementation examples.

TODO: add hidden field to X3DGroupingNode nodes


5.b. Environment node for gamma correction - comments on mailing list, more to follow.  Nicholas tracking.



5.c. Discussion: how to we specify types in metadata sets and metadata schemas?

Related issue: should 'name' field be NMTOKEN or SFString?  The answer varies.  This is a shared issue for Metadata, CAD, HAnim, protos, field/fieldValue definitions, DEF/USE (type ID/IDREF), ROUTE (IDREF), IMPORT/EXPORT etc.

We had a long and interesting discussion on metadata schemes, looking at an example that Nicholas is construction.

Of course in all cases when considering resolution of issues, our precedence of priorities should be along the lines of
- what is correct answer for X3Dv4,
- potential impacts on tools and content,
- does specification need change from X3Dv3.3,
- best way to achieve content validation to match.

Naming conventions are especially pertinent as far as data models go.  How strict should we be with respect to names?  The X3D Abstract Specification is often silent about this, requiring interpretation or deserving better clarity.  More about naming conventions can be found in the X3D Scene Authoring Hints.

- meta Statements
- Metadata Nodes
- Naming Conventions
The primary distinction being made in the X3D XML Schema and DOCTYPE tend to be
- NMTOKEN (no whitespace) for names that are identifiers or strict enumerations, such as Prototype names
- SFString (whitespace allowed) for names that are less formal.
- ID/IDREF (unique NMTOKEN values) for DEF/USE names that have to be validated and strictly referred to (for example, by ROUTE statements).

In general, since metadata schemes by other parties can vary greatly, we agreed to *not restrict the presence of whitespace in names* that might be defined by other taxonomies and don't affect scene-graph integrity.

*For review: proposed typing of 'name' fields follows*

- No space allowed:   Prototypes, field/fieldValue, vertex nodes (used by shader programs), UNIT
- Whitespace allowed: CAD, HAnim, meta statement, Metadata nodes

Also noticed an inconsistency: sometimes the schema uses schema type xs:NMTOKEN and sometimes xs:token.  A close read of the XML Schema Recommendation shows that they are nearly identical, with xs:NMTOKEN defined to exactly match DOCTYPE NMTOKEN (for backwards compatibility) while xs:token has identical constraints on values, and allows further restrictions on types via a regular expression (regex) pattern.  I believe that xs:token is what we want to apply consistently in X3D XML Schema.

- W3C XML Schema Definition Language (XSD) 1.1 Part 2: Datatypes, 3.4.2 token

- W3C XML Schema Definition Language (XSD) 1.1 Part 2: Datatypes, 3.4.4 NMTOKEN

Of note is that the following pending Mantis issue, which notes that 7.3.4 X3DMetadataObject specifies
"The specification of a non-empty value for the name field is required."  Recommend we keep spec unchanged and clear the issue.

* 764: 7.3.4 X3DMetadataObject - Is name field required?
   related to issue 530, which was resolved.

Multiple TODO action items will immediately flow from these decisions.

- Review, resolve proposed typing of 'name' fields
- Replace XML Schema xs:NMTOKEN types with SFString or xs:token, as appropriate
- Confirm XML Schema and XML DOCTYPE match as closely as possible
- Update X3DUOM, X3DJSAIL Java, X3DPSAIL Python, X3D Tooltips
- Add warnings (or relax errors) to X3D Tidy and X3D Schematron, as appropriate
- Check X3D Examples by unit testing

Future challenge shared by most of our working groups: comprehensive/flexible mapping of metadata taxonomies and validation of model content.


5.d. Next issues to pursue... suggest participants identify one issue and be prepared to address it each week.

* TODO: update status for unassigned Mantis tasks (will filter and display on screen)

* 1092: 7 Core component - MetadataSet or Metadata* node(s) as root nodes

* Metadata default containerField: some discussion, more to follow next week.
   where is our Mantis issue for that??

* 717: 7.3.4 X3DMetadataObject - Add value field

* 753: Assigning metadata to an entire X3D world - Incorrect link

Propose resolving (closing) the following issues as already complete - comments welcome.

* Issue 764, covered above

* Future feature: - New Field Access Type

* ProtoInstance name not required
   Mantis issue 1168: 4.3.10 ProtoInstance and fieldValue syntax - ProtoInstance USE requirement for name field should be removed

5.e. Michalis has made great progress with his online converter! Let's take a look at it together next week.  8)

* [x3d-public] Convert to X3D (from glTF, OBJ, STL, Collada, ...) and change X3D encodings using online Castle Game Engine converter


6. *Teleconference Information*

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We meet regularly on Fridays 0800-0930 pacific.  To join the teleconference:

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Participants review the public minutes to confirm that no member-only information is present.

Lots of effort continues.  Thanks to everyone contributing, your work is important to all of us.

Everyone else, please consider how you are helping... there are things TODO for everyone.

We will schedule several small items and one more significant Mantis issue each week, repeating until done.

Our current emphasis is to resolve all Mantis issues affecting Schema/DOCTYPE/X3DUOM to match X3Dv4 spec nod signatures so that implementations and examples can proceed with full confidence and clarity.

Thanks for all contributions today.  Have fun with X3D!  8)

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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