[x3d-public] X3D minutes 12 May 2021: X3D4 draft-specification ballot approved by ISO, SFString analysis, Blender meeting plans

Don Brutzman brutzman at nps.edu
Sat May 22 19:41:15 PDT 2021

Attendees: Vince Marchetti, Dick Puk, Don Brutzman.  Regrets: Anita Havele.  Missing in cyberspace: Nicholas Polys.

1. X3D4 draft-specification ballot approved by ISO!

Great news...  8 nations voted yes, 0 nations voted no, 4 nations abstained from recent ballot of the offered X3D4 Committee Draft.

Interesting progress in many respects.  For ISO procedural reasons, this is now considered a new work item proposal (NP) and thus the formal CD will be resubmitted in the future.

The only comments received were by Web3D Consortium - our long list of approximately 250 editorial corrections found in Web3D Mantis Issue Tracker.

We agreed to proceed as follows:

a. Save balloted version as a .zip and source tree
b. It is available in Web3D github as "CD"
c. We will begin editing that with same CSS markup style, reviewing/integrating 200+ editorial comments.
d. This means that there will be 2 progressive diff versions of the X3D4 specification, together showing all changes from X3D3.3 to X3D4.

Next priority for Dick and myself is pursuing those editorial issues.  Unfortunately it delays work on other specifications but it is important to finish.


2. SFString analysis

We continued slogging, reviewing in complete detail the useful analysis of SFString examples that Vince posted.

[2.0] X3D WG May 14 minutes : SFString in XML encoding examples

Key to resolving long-lingering mismatch in edge-case understandings:

a. XML encoding applies XML parsing rules to produce a string parsable using ClassicVRML Grammar rules,
b. ClassicVRML parsing rules should be applied identically for each encoding,
c. Result is "in-memory" string value that gets rendered.

Key reference:

[2.1] ClassicVRML Annex A Grammar

Excellent surprise, going example-by-example we discovered another mismatched interpretation.  There is and ambiguity in A.1.2 regarding whether a construct like "\i" is allowed or not.  The specification does not say, and our understanding of Backus-Naur Form (BNF) governing the grammar was not identical.

Adding a statement like one of the following is a useful candidate addition.

a.  "Other uses of backslash character are not valid."
b.  "Other uses of backslash treat the following character as a literal and are not rendered, a solitary backslash as last character of a string is not valid."

Vince had a post-meeting email as well.

[2.2] Discussion of SFString during May 21 X3D WG meeting

Of note is that BNF is fully formal (indeed a language for Grammar) so the Annex A interpretations complementing them (with preceding addition) seem excellent to me.  No doubt we'll continue with examination of examples.


3. X3D Wish List and Blender meeting plans

[3.0] Projects Wish List

Several prior links for Blender work are provided there, but they are pretty dated and deserve updating.

We've agreed to dedicate a meeting to Blender efforts

Goal: define technical objectives and coordinate efforts to document gaps and improved Blender export/import capabilities.

We will find a time that Nicholas can attend... not next week.

This is important!  Fridays look tricky...  We will dedicate Tuesday 0800-0900 starting June 1 to getting organized on Blender and X3D4.


4. Paraview supports VRML but not X3D?  Surprising, we are reaching out.

[4.0] Paraview: Read X3D data

but does support exporting X3D.

[4.1] Paraview Desktop

> Exporting Scenes
> ParaView supports exporting rendered scenes in formats use by 3D rendering tools, e.g. VRML, X3D, and GEO (Houdini geometry files). These can then be imported into tools that support photorealistic rendering, for example. You can also save out the scene as a self-contained HTML page that uses WebGL to do all the rendering in a Web browser.

Wondering if this shortfall is fixable in the ParaView open source?

In any case, some effort is likely needed to support X3D4 advancements (especially advanced visualization improvements using glTF/PBR) and so it is good to help.

Would anyone like to be lead on this outreach activity?


5. X3D-Edit 4.0 beta testing and Xj3D improvements are progressing

Lots of activity.  Have confirmed it is runnable on Windows, Mac and Linux.  Just upgraded to OpenJDK 16.0.1 and Ant 1.10.10.  Next adding X3dToTurtle export for X3D Ontology.

Xj3D (now version 2.3) improvement includes removal of aviatrix double buffering which is no longer needed with advanced jogamp libraries.

All progress and issue reports welcome.

[5.0] X3D-Edit 4.0 Authoring Tool for Extensible 3D (X3D) Graphics

[5.1] Xj3D viewer: NPS source


Have fund with X3D4!   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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