[x3d-public] Request for X3D encoding comment output from X3DPSAIL

[John Carlson]

For example, it nearly requires program to do this in Python or Perl.

Claude.ai reports:

perl -i -0pe 's/<!--(.*?)-->/join("\n", map {"<!-- $_ -->"} grep {s|^\s*||;
s|\s*$||; $_} split("\n", $1))/gse' file.xml

Obviously I can put this in a shell script, but I like stuff I can
understand!

Something in Java would be great!  Maybe I’ll write and contribute if it
doesn’t already exist?

Seems like a simple SAX parser, frankly!

John

On Sun, Jan 4, 2026 at 3:10 PM John Carlson <yottzumm at gmail.com> wrote:

> Thanks, it wasn’t clear to me that multi-line comments were not supported
> in X3D XML encoding.  That clears up most of my questions!
>
> I will replace multi-line comments with single-line comments in my
> examples.   Does X3D-Edit support this feature?  This would be great, and
> encourage me to use it!
>
> John
>
> On Sun, Jan 4, 2026 at 2:46 PM Don Brutzman <don.brutzman at gmail.com>
> wrote:
>
>> For clarity, here is a recap of key points that can be found in prior
>> responses and ticket issues:
>>
>>    - Persistent single-line comments are an important feature for X3D
>>    model conversions and interoperability.
>>    - You are welcome to use all Python features, including multi-line
>>    comments, whenever programming with Python and x3d.py.
>>    - Individual multi-line comments are not supported in a number of
>>    file encodings and programming languages.  Nor are they defined by X3D
>>    Architecture, nor are they supported by several X3D encodings (such as XML
>>    and ClassicVRML).  Thus multi-line comments are not a required feature.
>>    - Persistent comments in x3d.py Python are already supported via a
>>    Comment class.
>>    - Persistent single-line comments are now partially supported by
>>    X3dToPython.xslt converter, if present as children of Scene head and
>>    grouping nodes.  Further future work on content-model representations in
>>    the Python class hierarchy may be able to add them elsewhere (e.g. inside
>>    Shape Appearance Material geometry etc.
>>    - Tickets are closed after careful review if they are unrepeatable or
>>    unactionable.  Suggestions and questions about a clearer ticket are usually
>>    included.
>>
>> Hope this helps.
>>
>> all the best, Don
>> --
>> X3D Graphics, Maritime Robotics, Distributed Simulation
>> Relative Motion Consulting  https://RelativeMotion.info
>>
>>
>> On Sun, Jan 4, 2026 at 5:57 AM John Carlson <yottzumm at gmail.com> wrote:
>>
>>> Blowing off some steam.  Apologies, I probably should work out instead.
>>>
>>> I am unsure if it’s easier to output straight line code instead of
>>> hierarchical code in Python; multi-line non-persistent comments might
>>> become easier in straight line code.  I don’t know about comments() in
>>> XSLT.  In straight line code, wrapping a multi or single line comment in
>>> “””…””” is a cinch.  Even if newlines need to be added for the Python
>>> interpreter.
>>> AFAIK, I’ve already mentioned that straight line code is easier to debug,
>>> in my mind.  I think the Java large file discussion is still open; I
>>> know hierarchical code is more succinct, and less likely to stack
>>> overflow.  I think the choices between code structure in Python and Java
>>> might be different.
>>>
>>> Persistent multi-line comments are desirable, even if they aren’t
>>> present in the archive.  We will probably make different choices between
>>> hierarchical and straight line code when this feature is available.
>>>
>>> Short term hacks like single line comments work until features are
>>> introduced.  That doesn’t mean tickets should be closed prematurely, or
>>> examples outside the archives are invalid.
>>>
>>> John
>>>
>>> On Tue, Dec 30, 2025 at 3:42 AM John Carlson <yottzumm at gmail.com> wrote:
>>>
>>>> Don, thanks for your comment on this ticket that naively adding Comment
>>>> to a children field might not work.  That was one of my intentions on
>>>> expressing myself so vocally.  I apologize for using your time to do this,
>>>> but I think it revealed a possible design consideration.  I think if I had
>>>> discovered it, it would have gone over like a wet balloon.
>>>>
>>>> Thank you again, I will not put comments arbitrarily in the scenegraph
>>>> for now with my PythonSerializer.js, until you indicate it’s ready!   I
>>>> will leave them out of the scenegraph, as they are now.   Since I handle
>>>> comments generically, I will have to research the nodes you’ve accomplished.
>>>>
>>>> Now, can we have other multi-line comments, not in the persistent
>>>> scenegraph, in Python translated from .x3d, in the short term, like:
>>>>
>>>> #
>>>> # This is comment line 2
>>>> # This is comment line 3
>>>> #
>>>>
>>>> ?
>>>>
>>>> John
>>>>
>>>> From the ticket:
>>>>
>>>> “
>>>>
>>>> This is not an easy fix for converting files because Comment is not
>>>> part of the content model for all nodes. Solving this will probably require
>>>> extending class _ X3DNode in x3d.py and sorting out possible subclass
>>>> collisions. It will also be difficult to retain the original order of child
>>>> nodes and child comments within a parent node.
>>>>
>>>> This might be fixable someday - after some effort I got it working for
>>>> head, Scene, field, fieldValue.. Deferred as future work.
>>>>  ”
>>>>
>>>> On Mon, Dec 29, 2025 at 12:52 PM Don Brutzman <don.brutzman at gmail.com>
>>>> wrote:
>>>>
>>>>>
>>>>> I have posted a new ticket to capture this point.  Perhaps a useful
>>>>> exemplar, as well.
>>>>>
>>>>>    - X3D SourceForge ticket #82 creating persistent comments in
>>>>>    python when converting from XML
>>>>>    - https://sourceforge.net/p/x3d/tickets/82/
>>>>>
>>>>> Hope this helps.  Again thanks for your many efforts.  Have fun
>>>>> improving X3D!  🤔 👍
>>>>>
>>>>>>
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