[x3d-public] Simplifying ProtoInstance nodes
John Carlson
yottzumm at gmail.com
Sun May 11 11:18:52 PDT 2025
Ok, it looks like I misread this last night. I read “allow authors to
somehow cleverly apply such a feature.”
Sorry for the confusion. With “discourage,” I’m not sure of the grammar.
I think we’re pretty much in agreement that Protos *shouldn’t* override
builtins, and Protos shouldn’t override Protos.
But yeah, leaving things undefined may speed up logic, or leave something
difficult to debug.
John
On Sat, May 10, 2025 at 4:27 PM Andreas Plesch via x3d-public <
x3d-public at web3d.org> wrote:
>
> 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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