[x3d-public] Simplifying ProtoInstance nodes

Sat May 10 14:26:29 PDT 2025

I actually think I have never tested when a Proto has the same name as a
native node in x3dom.

Here is an example for 'Box':

https://andreasplesch.github.io/Library/Viewer/index.html?url=https://gist.githubusercontent.com/andreasplesch/5e2c6068d0495605198f9a20254c7519/raw/91ee41a9afbb8ee9dec5952108bf13bdc41f4de0/ProtoBoxCollision.x3d

It appears that the Proto redefinition takes precedence.

Here is an example for 'Group':

https://andreasplesch.github.io/Library/Viewer/index.html?url=https://gist.githubusercontent.com/andreasplesch/5e2c6068d0495605198f9a20254c7519/raw/3b7a53131c0c890b9672b38ae083c81c8524d60e/ProtoNativeCollisionTest.x3d

This is more complicated but I think the Proto definition still takes
precedence except that now only the first child of the type transform is
rendered.

I would suggest letting browser behaviour for that case remain undefined to
discourage authors to somehow cleverly apply such a feature.

Andreas Plesch
Waltham, MA 02453

On Sat, May 10, 2025, 3:39 PM <x3d-public-request at web3d.org> wrote:

> Date: Sat, 10 May 2025 21:37:47 +0200
> From: Holger Seelig <holger.seelig at yahoo.de>
> To: X3D <x3d-public at web3d.org>
> Subject: Re: [x3d-public] Simplifying ProtoInstance nodes
> Message-ID: <67EB2216-BC2C-4A50-9E57-122241628399 at yahoo.de>
> Content-Type: text/plain; charset="utf-8"
>
> There is another drawback which already exist in VRML encoding. What take
> precedence if a PROTO is named as a build-in node. Consider a PROTO named
> Box with a Sphere as root node. What is happening if a Box is now
> instantiated?
>
> PROTO Box []
> {
>   Sphere {}
> }
>
> Shape {
>   Box {}
> }
>
> This behaviour is not handled by the specification, but X_ITE does the
> following: build-in nodes will take precedence over over PROTO nodes, it
> will still display a Box node. Don?t know what Caste or X3DOM does. With
> current XML encoding this is very cleared and there is no prob at all. But
> in VRML encoding or with XML ?short syntax? this may be worth a spec
> comment.
>
> Best regards,
> Holger
>
> --
> Holger Seelig
> Leipzig, Germany
>
> holger.seelig at yahoo.de
> https://create3000.github.io/x_ite/
> https://patreon.com/X_ITE
>
>
>
> > Am 10.05.2025 um 20:44 schrieb Brutzman, Donald (Don) (CIV) via
> x3d-public <x3d-public at web3d.org>:
> >
> > +1 on all counts, thanks for thoughtful consideration Michalis.
> >
> > Further considerations are always welcome.
> >
> > Next week Dick and I will review comments, then consider a Mantis issue
> and draft prose addition to X3D XML Encoding.
> >
> > all the best, Don
> > --
> > Don Brutzman  Naval Postgraduate School, Code USW/Br
> brutzman at nps.edu <mailto: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: Michalis Kamburelis
> > Sent: Saturday, May 10, 2025 11:38 AM
> > To: Extensible 3D (X3D) Graphics public discussion
> > Cc: Brutzman, Donald (Don) (CIV)
> > Subject: Re: [x3d-public] Simplifying ProtoInstance nodes
> >
> > I think this short form (in XML encoding) makes sense, and Castle Game
> Engine / Castle Model Viewer could support it too.
> >
> > It makes XML encoding and classic encoding more consistent: you can use
> PROTO to define a new node, and then use the new node with the same syntax
> as "built-in nodes". This is already true for classic encoding, it's nice
> to bring this feature to XML encoding.
> >
> > Don has already expressed the important drawback of this "short form":
> such XML will not validate. I mean, it will validate in X3D-specific tools
> like "castle-model-converter --validate .." (once we add support for it),
> but the general XML validation using XML Schema has no way of validating
> it. You cannot tell in XML schema "this XML element name is valid, if
> defined by some XML attribute elsewhere". I'm guessing this was the whole
> reason why ProtoInstance, fieldValue etc. were invented in XML encoding.
> >
> > I'm guessing in JSON X3D encoding, the consideration will be similar: it
> can be implemented, but the resulting file will not validate with JSON
> schema ( https://json-schema.org/ ).
> >
> > Anyhow, if we're all fine with accepting this drawback, then we sure can
> go ahead and add it to spec :) As long as "long form" remains available,
> and thus tools like XML schema and JSON schema remain useful, I think it
> makes sense to have this choice.
> >
> > Regards,
> > Michalis
> >
> > sob., 10 maj 2025 o 18:38 Brutzman, Donald (Don) (CIV) via x3d-public <
> x3d-public at web3d.org <mailto:x3d-public at web3d.org>> napisa?(a):
> > Thanks for the interesting, innovative discussion.  Excerpting the
> example:
> >
> >
> https://create3000.github.io/x_ite/tutorials/creating-new-node-types/#using-prototyped-nodes
> >
> > _________________________
> > XML Encoding
> > 1
> > 2
> > 3
> > 4
> > 5
> > 6
> > 7
> > 8
> > 9
> > <!-- Official Syntax -->
> > <ProtoInstance name='BouncingBall'>
> >   <fieldValue name='cycleInterval' value='2'/>
> >   <fieldValue name='bounceHeight' value='3'/>
> > </ProtoInstance>
> > <!-- Short Syntax -->
> > <BouncingBall
> >     cycleInterval='2'
> >     bounceHeight='3'/>
> > Classic VRML Encoding
> > 1
> > 2
> > 3
> > 4
> > BouncingBall {
> >   cycleInterval 2.0
> >   bounceHeight  3.0
> > }
> > _________________________
> >
> > One drawback with the "short" XML syntax is that it will not pass XML
> DOCTYPE or XML Schema validation, although it still must conform to XML
> well-formed rules.  Additional tool-specific capabilities can check for
> such correctness during parsing, of course.  Avoiding XML validation
> relaxes quality assurance (QA)  for the entire scene, not just that
> prototype instance, and so use of the short form should be considered
> carefully.
> >
> > Of course there is much merit too, not least of which are readability
> and consistency with other XML-encoded nodes.
> >
> > As it turns out, now is a good time to consider such a change to the X3D
> Standards suite.  We have highly mature documents defining X3D encodings
> using XML and ClassicVRML syntax.  Conceivably a "short" form for
> ProtoInstance will carry over satisfactorily for JSON and other encodings
> as well, when we get to them this fall.
> >
> > If X_ITE and X3DOM already handle this form, and if Castle Model Viewer
> (Castle Game Engine) is also supportive, I'm not yet seeing any blockers to
> adoption.  Further implementation and evaluation of course will be useful
> >
> > Reference and specific clause that would need modification:
> >
> > X3D XML Encoding 4.0 <
> https://www.web3d.org/specifications/X3Dv4Draft/ISO-IEC19776-1v4.0-WD1/Part01/X3D_XML.html>
> revision 19776-1
> > 4.3.3.2  ProtoInstance node and fieldValue statement syntax
> >
> https://www.web3d.org/specifications/X3Dv4Draft/ISO-IEC19776-1v4.0-WD1/Part01/concepts.html#ProtoInstanceAndFieldValueStatement
> >
> > Probably no changes needed:
> >
> > X3D Classic VRML Encoding 4.0 <
> https://www.web3d.org/specifications/X3Dv4Draft/ISO-IEC19776-2v4.0-WD1/Part02/X3D_ClassicVRML.html>
> revision 19776-2
> > 4.3.3.2 Prototype instances and field value initialization syntax
> >
> https://www.web3d.org/specifications/X3Dv4Draft/ISO-IEC19776-2v4.0-WD1/Part02/concepts.html#ProtoInstanceAndFieldValueStatement
> >
> > X3D Architecture 4.1 <
> https://www.web3d.org/specifications/X3Dv4Draft/ISO-IEC19775-1v4.1-CD//Part01/Architecture.html>,
> revision 19775-1
> > 4.4.4 Prototype semantics
> >
> https://www.web3d.org/specifications/X3Dv4Draft/ISO-IEC19775-1v4.1-CD//Part01/concepts.html#PrototypeSemantics
> >
> > Thanks for careful consideration of this potential capability.  All
> feedback welcome.
> >
> > Have fun with X3D extensibility!  ?
> >
> > all the best, Don
> > --
> > Don Brutzman  Naval Postgraduate School, Code USW/Br
> brutzman at nps.edu <mailto: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: x3d-public on behalf of Holger Seelig via x3d-public
> > Sent: Saturday, May 10, 2025 1:13 AM
> > To: X3D
> > Cc: Holger Seelig
> > Subject: Re: [x3d-public] Simplifying ProtoInstance nodes
> >
> > This is already possible if you use the ?short syntax? of a proto
> instance:
> >
> >
> https://create3000.github.io/x_ite/tutorials/creating-new-node-types/#using-prototyped-nodes
> >
> > You can use this in X_ITE, but also in X3DOM.
> >
> > Best regards,
> > Holger
> >
> > --
> > Holger Seelig
> > Leipzig, Germany
> >
> > holger.seelig at yahoo.de <mailto:holger.seelig at yahoo.de>
> > https://create3000.github.io/x_ite/
> > https://patreon.com/X_ITE
> >
> >
> >
> > Am 10.05.2025 um 05:55 schrieb John Carlson via x3d-public <
> x3d-public at web3d.org <mailto:x3d-public at web3d.org>>:
> >
> > My thought is to replace ?ProtoInstance? tags with ?MenuItem? tags, and
> fieldValue statements with attributes, but I?ve not done that before. My
> goal is to make the model more accessible to screen readers.
> >
> > Any examples are welcome.
> >
> > See attached link and model.
> >
> > John
> >
> > ---------- Forwarded message ---------
> > From: John Carlson <yottzumm at gmail.com <mailto:yottzumm at gmail.com>>
> > Date: Thu, Mar 6, 2025 at 4:35?PM
> > Subject: Latest cleaned Jin FACS (needs metadata)
> > To: Don Brutzman <brutzman at nps.edu <mailto:brutzman at nps.edu>>, Joe D
> Williams <joedwil at earthlink.net <mailto:joedwil at earthlink.net>>
> >
> >
> > Attached.
> >
> > And:
> >
> https://create3000.github.io/x_ite/playground/?url=https://raw.githubusercontent.com/coderextreme/ci2had/refs/heads/main/resources/CleanedYouClocks.x3d
> >
> > John
> > <CleanedYouClocks.x3d>_______________________________________________
> > x3d-public mailing list
> > x3d-public at web3d.org <mailto:x3d-public at web3d.org>
> > http://web3d.org/mailman/listinfo/x3d-public_web3d.org
> >
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