[x3d-public] X3D Working Group meeting 23 SEP 2022: X3DApplication Stack Layers Alternatives diagram refinement

Sat Sep 24 11:45:55 PDT 2022

➢ Require, Design, Implement, Release/Produce/Emit, Consume/Collect.

+ Recycle, Reuse … 

From: John Carlson
Sent: Saturday, September 24, 2022 11:26 AM
To: Christoph Valentin
Cc: X3D Public Mailing List (x3d-public at web3d.org)
Subject: Re: [x3d-public] X3D Working Group meeting 23 SEP 2022: X3DApplication Stack Layers Alternatives diagram refinement

Personally, I think we’re all trying to figure out how X3D fits into the Metaverse, which was why i was trying to come up with things we might want to do in the Metaverse, and what might appear in the Metaverse.

For me, i may want to show the X3D standard in the Metaverse.

John 

On Sat, Sep 24, 2022 at 1:16 PM Christoph Valentin <christoph.valentin at gmx.at> wrote:
Hi all together,

May I ask one question?

What is the purpose of the diagram?

I understood the diagram as a help for decision, if someone likes to implement an "X3D Application" and wants to know, which kind of expertise they will need.

True?

Kr,
CP/V

P.S.: on the other hand, the diagram I suggested earlier this week, was just a "rough overview for starters", about how X3D fits into any computer system.

Gesendet: Samstag, 24. September 2022 um 20:05 Uhr
Von: "John Carlson" <yottzumm at gmail.com>
An: "Brutzman, Donald (Don) (CIV)" <brutzman at nps.edu>
Cc: "X3D Public Mailing List (x3d-public at web3d.org)" <x3d-public at web3d.org>
Betreff: Re: [x3d-public] X3D Working Group meeting 23 SEP 2022: X3D Application Stack Layers Alternatives diagram refinement
More verbs:

Require, Design, Implement, Release/Produce/Emit, Consume/Collect.

More nouns:

Source, Sink

On Sat, Sep 24, 2022 at 1:00 PM John Carlson <yottzumm at gmail.com> wrote:
Perhaps we should focus on Author/Creator, Read/View, Manipulate/Update/Edit/Transform/Convert, Debug/Test, Secure,  Compress/Decompress, Publish/Evangelize, Buy/Browse, Sell/Purvey, more verbs. … Archive

On all our main classes:

Standards, Object Models, Conversion Programs, Worlds, Scenes, Models, Examples, Renderings, Bindings, Encodings, Schemas, Files, Tools/Browsers/Apps/Libraries

So on one axis we put verbs, and on other axis we put nouns/classes.

I’m not really pushing my way.  I think it better demonstrates where work needs to be done.

In particular, our standards don’t refer to monetization at all.  GNU at least advocates selling support, there’s Patreon, Odysee and 3D model stores.

Thanks, Don, for helping get beyond simple CRUD-GR!

Woohoo!

John

On Sat, Sep 24, 2022 at 10:12 AM Brutzman, Donald (Don) (CIV) <brutzman at nps.edu> wrote:
John wrote:
• “Looked at layers and alternative attachment.  I’m wondering why there’s two boxes for converting?“

Good point.  There are two similar concepts I’m trying to distinguish:
        (a) 3D models can be converted for reuse offline,
        (b) translator libraries offer programming-library options for applications.

Attached please find this morning’s update.  Added a caption for further explanation:

• “X3D is interoperable with diverse technologies, providing multiple choices to developers.”

Complicated territory – does this help describe the many options available with X3D?  Am striving for clarity and simplicity, if possible.  Hopefully this diagram continues to improve, and might help us show the X3D value propositions more widely, including to Metaverse Standards Forum participants.

Further review and comment by all is welcome.

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 https:// faculty.nps.edu/brutzman

From: Brutzman, Donald (Don) (CIV)
Sent: Friday, September 23, 2022 11:43 AM
To: X3D Public Mailing List (x3d-public at web3d.org) <x3d-public at web3d.org>
Cc: brutzman at nps.edu
Subject: X3D Working Group meeting 23 SEP 2022: Mantis issues review, ballot deadlines, X3D Application Stack Layer Examples diagram

Attendees: Dick Puk, Don Brutzman

1. We first reviewed the two recently posted Mantis issues regarding SVG and QIF.  We also looked at a Mantis issue posted earlier this year relating to scalable composition of really large X3D worlds.  Selected details follow.

a. Mantis 1400: add Scalable Vector Graphics (SVG) to recommended image formats for ImageTexture
https://www.web3d.org/member-only/mantis/view.php?id=1400

SVG references:

* https://www.w3.org/Graphics/SVG
* "SVG is a markup language for describing two-dimensional graphics applications and images, and a set of related graphics script interfaces."

Dick estimation: thinks SVG is a 2D scene-graph definition language. It can result as an image, though so can X3D.

This issue suggests that SVG be listed as a recommended (optional) format that can be rendered as an ImageTexture, using the default presentation settings of the SVG model.

Of note is that browsers are not forbidden from implementing SVG as an ImageTexture format, and also that SVG-to-PNG converters are commonplace.

Of further note is that the DPS minutes already showed a use case for SVG as ImageTexture, namely conversion of metadata information as a carefully laid-out annotation image that is billboarded in context. Having direct SVG rendering would eliminate the offscreen conversion step, permitting direct integration of X3D models with other HTML/SVG web graphics.

Concern: don't want to overcomplicate the existing ImageTexture functionality as a 2D array of pixels. Once generation of pixels becomes a computational process, this is different functionality for the ImageTexture node. This might raise further concerns about impact of ImageTexture computational complexity in various profiles (such as Interchange Profile).

Possible alternate: define SvgTexture node? What fields would it have?
Suggested possible resolution:

a. Browsers are welcome to implement ImageTexture as an allowed url format if they see fit,
b. SvgTexture ought to be designed and considered as a possible new node,
c. ComposedImageTexture (or somesuch) might be designed and considered as an even-more general possibility for comuputational 2D imagery,
d. Following further practical experience, defer any specification-change recommendations to future X3D4.1.

b. Mantis 1401: aligning X3D4 LineProperties with Quality Information Framework (QIF) specification
https://www.web3d.org/member-only/mantis/view.php?id=1401

Suggested resolution:

a. The concepts are directly aligned and overlapping, with some additions by QIF.
b. This ISO standard does not appear to have been considered by SC24 or JTC1.
c. Close scrutiny of both terms and definitions needs to be performed before any changes might be recommended.
d. If changes are indeed warranted and acceptable, then they likely need to first considered as part of the Registry of Items, specifically entries for linestyle and hatchstyle.
e. At that point, amendment of X3D to stay aligned with Registry of Items (or possibly add further styles independently) can be considered.
f. Defer to X3D 4.1.

Meanwhile note in Web3D current ballot comments the need to fix the table erratum previously noted.

c. Mantis 1192: 07.2.2 Bindable children nodes - Undefined results if bindable node is under Switch or LOD is problematic
https://www.web3d.org/member-only/mantis/view.php?id=1192#bugnotes

Comment on 19775-1: Abstract X3D Definitions - V3.3
7.2.2 Bindable children nodes
http://www.web3d.org/documents/specifications/19775-1/V3.3/Part01/components/core.html#BindableChildrenNodes

-----------------
Subject: Undefined results if bindable node is under Switch or LOD is problematic

Spec sayeth:
"The results are undefined if a bindable node is bound and is the child of an LOD, Switch, or any node or prototype that disables its children."

This leads to all manner of inconsistent problems among scenes. It also means that Inline node (which may or may not include bindable nodes) has undefined behavior under LOD/Switch/etc.

As a result, in addition to indeterminate X3D browser behavior, it means that X3D scenes are not fully composable. That is contrary to X3D design objectives.

Different prose and deterministic guidelines is needed in this section that provides clear rules for binding/unbinding nodes when they become active within LOD/Switch/etc. Small adaptations to current binding rules can likely address this problem satisfactorily.

Related: Mantis issue 749

April 29:
Analysis during X3D Working Group call:

a. Switch would keep each binding stack aligned with whichever child was active, thereby binding and unbinding nodes whenever the Switch level is modified.

b. LOD would have all of its child bindable nodes on the binding stack throughout, so that user experience was consistent. For example, it would make no sense for Viewpoints to get arbitrarily unbound and bound, based on range to viewer, as a user independently navigated through a scene.

c. LOD attempting to maintain author intent has access to all Viewpoint nodes on binding stack, and range-to-viewer LOD transitions are either flexible suggestions (browser-optimization control) or rigidly enforced (forceTransitions field is TRUE). Thus if a node is subsequently bound by user in a different inactive LOD child branch, then that binding event is honored and that LOD child branch becomes the active child branch. This binding event (and changed LOD child branch selection) takes precedence over browser range/performance considerations, and also takes precedence over whatever value is provided in forceTransitions field. (Example: selecting a room Viewpoint while in a large building model).

d. NavigationInfo, Background and Fog binding stacks and responses to binding events should behave identically to Viewpoint. Variations would be exceedingly complex and not understandable. Consistency means that author intent and user action always take precedence, for Switch and LOD response.

Spec editors work on integrating these principles as specification prose (we are close already) and report back recommended changes to X3D working group.

Don's opinion: this will significantly help user-sensible scalability of huge (perhaps Metaverse-scale) models using many Inline and prototype nodes, enabling predictable and performant navigation and traversal throughout.

Today’s session.

Alternatives deserving working-review consensus:

a. Recommending this clarification of undefined prior specification prose might add important value, or might be construed as a technical change to X3D4.0 that possibly requires future re-balloting as another X3D 4.0 DIS (which is not an acceptable outcome).

b. If not balloted then this becomes an X3D4.1 issue.

c. Web3D might consider some alternative approach to strongly encourage adoption of this clarified approach in order to further encourage greater scalability of multi-world environments, and better alignment with shared Metaverse design imperatives. For example, are we creating a Best Practices Pending X3D 4.1 Approval document of some sort?

2. We only have 4 total issues to review as planned Web3D comments.  This will occur during a single working-group meeting, 7 OCT.

Deadline for X3D Ballot comments:
• OCT, Web3D comments to INCITS (U.S. National Standards Body
• TBD OCT, INCITS comments to SC24
• 4 NOV, SC24 comments to ISO

No meeting currently planned for 30 SEP.

3. Bonus round: we worked on the “layer” diagram from recent meetings a bit more.  Latest X3dApplicationStackLayerExamples is attached, all comments welcome.

Have fun with X3D!

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 https:// faculty.nps.edu/brutzman

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