[x3d-public] draft X3D 4.1 prose for font files and libraries

Holger Seelig holger.seelig at yahoo.de
Sat Mar 8 01:43:25 PST 2025


If I open a X3D scene with FontLibrary nodes in an editor like Castle or Sunrize, there is normally no knowledge about any parent scenes, thus FontLibrary should be scene scoped.

Best regards,
Holger

--
Holger Seelig
Leipzig, Germany

holger.seelig at yahoo.de
https://create3000.github.io/x_ite/

> Am 01.03.2025 um 15:45 schrieb Andreas Plesch via x3d-public <x3d-public at web3d.org>:
> 
> I basically had the same questions as Michalis.
> 
> Comments below.
>  
>> Date: Sat, 1 Mar 2025 05:52:24 +0100
>> From: Michalis Kamburelis <michalis.kambi at gmail.com <mailto:michalis.kambi at gmail.com>>
>> 
>> As for FontLibrary,
>> https://www.web3d.org/specifications/X3Dv4Draft/ISO-IEC19775-1v4.1-CD/Part01/components/text.html#FontLibrary
>> : I admit I don't understand this proposal (yet).
>> 
>> 1. Where is the FontLibrary actually used? It doesn't seem you can refer to
>> a FontLibrary node in any way. It's also not X3DChildNode, so you cannot
>> just place it in groups.
> 
> This is a big missing piece.
> After some thought, I think the idea is to give the X3D browser information on how to render fonts which are referenced in a FontStyle.family field. 
> One option is to think of it not as a Node but as a Statement describing a resource available to the X3D browser in general.
> Another option is to make it part of WorldInfo as a value for a new WorldInfo.fonts field ?
> The idea came up as an alternative to a FontStyle.url field, so see below.
>  
>> 2. The sentence """If present, only the first active font library retrieved
>> from the url list shall be used."""" --- What is the meaning of word "used"
>> in this sentence? Used for what?
> 
> What is 'active' ? Probably accessible
> 
> "Used": ?
>  
>> 3. """Individual font library files can be used by multiple FontStyle nodes
>> in a scene.""" -- How? FontStyle does not refer to FontLibrary. And I
>> understand in this version, FontStyle would not have its own FontStyle.url
>> field.
>> 
>>      Did you maybe want to add a field like "SFNode FontLibrary
>> fontLibrary" to FontStyle or Text? Or make FontLibrary a X3DChildNode?
> 
> That was my first thought as well but see above.
> A simple way to make a FontLibrary url available to multiple FontStyle nodes is by DEF/USE.
> A FontStyle.fontLibrary field is preferred over a global scope since it clearly associates a font to a FontStyle/Text.
> It is better not to have to rely on the family name to identify a font. Having to rely on the family name is more error prone for both the author and the browser.
> 
>> 4. A testcase, preferably many testcase(s), explaining the FontLibrary
>> usage (X3D files + intended rendering) would very helpful. (Same goes for
>> the previous proposal actually.) Please provide testcases along with spec
>> prose -- they make the intention more obvious.
> 
> Including edge cases if possible.
> 
>> Overall, so far, I admit FontLibrary is confusing to me, I don't know what
>> it means. The previous proposal (extending FontStyle) seems more
>> straightforward -- a few people (including me) had feedback, but it seems
>> that we all "got the intention" of FontStyle.url correctly, we just pointed
>> some things to improve in wording.
> 
> One advantage of a FontLibrary (or perhaps just 'Font') node would be DEF/USE.
> 
> As mentioned multiple times, the spec. should include language that the FontStyle.style field may be ignored if a FontLibrary url is accessible as in most cases that url will only provide data for one specific style..
> 
> Regards, -Andreas
> 
>> 
>> pt., 28 lut 2025 o 19:56 Brutzman, Donald (Don) (CIV) via x3d-public <
>> x3d-public at web3d.org <mailto:x3d-public at web3d.org>> napisa?(a):
>> 
>> > Thanks everyone for responses, implementation improvements, technical
>> > details, and many insights.
>> >
>> > First positive takeaway:  WOFF File Format 2.0 is the clear preference to
>> > WOFF 1.0.
>> >
>> > WOFF File Format 2.0, W3C Recommendation, 08 August 2024
>> >
>> >    - "Abstract.  Based on experience with WOFF 1.0, which is widely
>> >    deployed, this specification was developed to provide improved compression
>> >    and thus lower use of network bandwidth, while still allowing fast
>> >    decompression even on mobile devices. This is achieved by combining a
>> >    content-aware preprocessing step and improved entropy coding, compared to
>> >    the Flate compression used in WOFF 1.0."
>> >    - https://www.w3.org/TR/WOFF2
>> >
>> > Clearly, from recent excellent emails, there are many implementer-specific
>> > issues and interactions when adding font files that are good to know about,
>> > but don't necessarily need to be expressed in an X3D model (or the X3D
>> > Architecture specification).
>> >
>> > Dick and I worked further today to assess whether separation of font files
>> > from FontStyle node into a FontLibrary node was the preferred to represent
>> > this information in an X3D model.  We also repeated WOFF Recommendation's
>> > use of term "collection" as part of a *FontLibrary *definition.
>> >
>> >    - The FontLibrary node specifies a collection of one or more font
>> >    family definitions. A font family may include one or more related font
>> >    style definitions. FontLibrary provides the ability to selectively load
>> >    font files for use by FontStyle
>> >    <https://outlook.office.com/mail/id/AAkALgAAAAAAHYQDEapmEc2byACqAC%2FEWg0AN5ikByHYYkeveIfklhUi1gAG%2Blh21AAA?nativeVersion=1.2025.219.400#FontStyle> and
>> >    ScreenFontStyle
>> >    <https://outlook.office.com/mail/id/layout.html#ScreenFontStyle> nodes.
>> >
>> > FontLibrary node pros (meaning separation of font files from FontStyle
>> > node):
>> >
>> >    - Keeps existing (and fairly complex) FontStyle implementations
>> >    unchanged
>> >    - Separation of loading and presentation functionality between two
>> >    nodes
>> >    - FontLibrary simply adds to the selection of fonts available, and
>> >    retains emphasis of *family *and *style *fields within a given
>> >    FontStyle node.
>> >    - If separate font files redefine a given family (with the same name),
>> >    then addition of *enabled *field might allow authors to determine
>> >    which of them is relevant.  However *enabled *field can be considered
>> >    redundant (since changing url has same effect).
>> >    - Alternative approach to use of an *enabled *field, we might also
>> >    need to add a sentence such as
>> >    - "If a font family is redefined by multiple FontLibrary nodes, then
>> >       the first defined family is used."
>> >       - (or we can remain silent and let browser implementations sort
>> >       that out)
>> >
>> > FontLibrary node cons (meaning bundle all url functionality in FontStyle):
>> >
>> >    - Closer coupling of *family *field and font files themselves, recent
>> >    email dialog indicates that sometimes the font file simply overrides the
>> >    family field...
>> >    - We do not want to change any defined functionality for *family* and *style
>> >    *fields, they still seem correct in X3D Architecture and no suitable
>> >    changes yet seen.
>> >    - No need for *enabled *field.
>> >
>> > Our current opinion is that FontLibrary provides a superior approach to
>> > continued growth of FontStyle node.  To facilitate comparison and review,
>> > current draft has proposed FontLibrary prose in yellow, and alternate
>> > (not accepted) FontStyle alternative in cyan.
>> >
>> >    - X3D 4.1 (draft) Architecture, clause 15 Text component, 15.4.1
>> >    FontLibrary
>> >    -
>> >    https://www.web3d.org/specifications/X3Dv4Draft/ISO-IEC19775-1v4.1-CD/Part01/components/text.html#FontLibrary
>> >    X3D Architecture 4.1 draft ? ISO/IEC 19775-1:202x ? 15 Text component
>> >    <https://www.web3d.org/specifications/X3Dv4Draft/ISO-IEC19775-1v4.1-CD/Part01/components/text.html#FontLibrary>
>> >    15.2.2.4 Language. The language field specifies the context of the
>> >    language for the text string in the form of a language and a country in
>> >    which that language is used. Both the language and the country are
>> >    specified using the language tags defined in which may specify only a
>> >    country (using the three-character codes defined in ISO 3166) or both a
>> >    language (using the two-character codes ...
>> >    www.web3d.org <http://www.web3d.org/>
>> >
>> >
>> > Additional questions to ponder, further insights welcome:
>> >
>> >    - Our impression of the term 'webfont' is that it is simply a generic
>> >    term, not a standard or specification per se, and often employed to
>> >    reference WOFF.  Is that correct?
>> >
>> >    - Font files tend to be large.  Might there ever be a use case where
>> >    an author chooses to define a font as source text in the url field?  We
>> >    have some precedent for this in Script url and (sorta) PixelTexture.
>> >    Nevertheless font definitions are also convoluted and (perhaps notoriously)
>> >    difficult to parse.  Of note is that WOFF2 specifically is designed for
>> >    effective binary compression.  Our inclination so far is to not describe
>> >    (or encourage) definition of the font within an X3D model.  YMMV (though we
>> >    doubt it).  Much better authoring approach is to use any of many conversion
>> >    tools that might credibly update a legacy font into WOFF2.
>> >
>> > Thanks everyone for leaning forward on this, looking ahead to continuing
>> > discussion.
>> >
>> > Have fun with font library collections for X3D models!  ?
>> >
>> >
>> > 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 <x3d-public-bounces at web3d.org <mailto:x3d-public-bounces at web3d.org>> on behalf of Brutzman,
>> > Donald (Don) (CIV) via x3d-public <x3d-public at web3d.org <mailto:x3d-public at web3d.org>>
>> > *Sent:* Wednesday, February 26, 2025 5:39 PM
>> > *To:* X3D <x3d-public at web3d.org <mailto:x3d-public at web3d.org>>
>> > *Cc:* Brutzman, Donald (Don) (CIV) <brutzman at nps.edu <mailto:brutzman at nps.edu>>
>> > *Subject:* Re: [x3d-public] draft X3D 4.1 prose for font files and
>> > libraries
>> >
>> > Dick and I worked on suggested prose for X3D 4.1 with details continuing
>> > in Mantis 1490 below.
>> >
>> > Review request:
>> >
>> >    - X3D 4.1 Architecture (draft), 15 Text component, 15.4.1 FontStyle
>> >    -
>> >    https://www.web3d.org/specifications/X3Dv4Draft/ISO-IEC19775-1v4.1-CD//Part01/components/text.html#FontStyle
>> >
>> > Improvements:
>> >
>> >    - Include all X3DURLObject fields,
>> >
>> >   SFTime   [in,out] autoRefresh          0.0    [0,?)
>> >   SFTime   [in,out] autoRefreshTimeLimit 3600.0 [0,?)
>> >   SFString [in,out] description          ""
>> >   SFBool   [in,out] load                 TRUE
>> >   MFString [in,out] url                  []     [URI]
>> >
>> >    - Decided to NOT overload functionality of *family * field by adding
>> >    file names (sorry Holger!  adjusting your implementation will likely be
>> >    simple in comparison)
>> >
>> >    - New prose:
>> >
>> > The *url* field is optional and can refer to a relative or online address
>> > for a font library that contains one or more font definitions. An empty
>> > *url* list indicates that the default set of fonts provided by the
>> > browser are used. If present, only the first active font library retrieved
>> > from the *url* list shall be used. Individual font library files can be
>> > used by multiple FontStyle nodes in a scene. Each font file only needs to
>> > be loaded once per session.
>> > X3D browsers shall support WOFF (MIME type application/x-font-woff) (see W3C
>> > WOFF File Format
>> > <https://www.web3d.org/specifications/X3Dv4Draft/ISO-IEC19775-1v4.1-CD//Part01/references.html#W3C_WOFF>).
>> > Support for the OpenType file format (MIME type
>> > application/x-font-opentype) (see OpenType Specification
>> > <https://www.web3d.org/specifications/X3Dv4Draft/ISO-IEC19775-1v4.1-CD//Part01/bibliography.html#OPENTYPE>)
>> > and TrueType file format (MIME type application/x-font-truetype) (see ISO/IEC
>> > 14496-22 Open Font Format
>> > <https://www.web3d.org/specifications/X3Dv4Draft/ISO-IEC19775-1v4.1-CD//Part01/references.html#I14496_22>)
>> > is also recommended.
>> > Security, licensing, and copyright/usage permissions are handled via the
>> > exposure of a font file itself.
>> > Support for the *autoRefresh*, *autoRefreshTimeLimit*, and *load* fields is
>> > optional.
>> > More details on the *autoRefresh*, *autoRefreshTimeLimit*, *description*,
>> > *load*, and *url* fields are contained in 9.2.1 URLs, URNs and URIs
>> > <https://www.web3d.org/specifications/X3Dv4Draft/ISO-IEC19775-1v4.1-CD//Part01/components/networking.html#URLs>
>> > .
>> > Looking it over, adding more functionality to FontStyle node seems to be
>> > unwise.  Dick has an excellent proposal:
>> > TODO alternative approach: move all new functionality into a separate
>> > *FontLibrary* node to avoid complicating FontStyle further. This also
>> > offers the ability to succinctly load multiple font libraries in a given
>> > scene. The expense of defining a new node for X3D is offset by clearer
>> > distinction between X3D 4.0 and 4.1, also simplifying model content
>> > significantly.
>> > Feedback is welcome.
>> > Leaving existing FontStyle implementations alone probably avoids many
>> > unintended side effects.  First law of engineering:  "If it ain't broke,
>> > don't fix it."
>> >
>> > Thanks for all review.  It feels like we are finally converging on a
>> > straightforward approach to valuable future capabilities.
>> >
>> > Have fun with X3D fonts!  ?
>> >
>> >
>> > 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:* Brutzman, Donald (Don) (CIV) <brutzman at nps.edu <mailto:brutzman at nps.edu>>
>> > *Sent:* Monday, February 24, 2025 9:32 AM
>> > *To:* X3D <x3d-public at web3d.org <mailto:x3d-public at web3d.org>>
>> > *Cc:* Holger Seelig <holger.seelig at yahoo.de <mailto:holger.seelig at yahoo.de>>
>> > *Subject:* Re: [x3d-public] Open dyslexic and/or (unfortunately)
>> > comicsans fonts; draft X3D 4.1 prose for font files and libraries
>> >
>> > Wow, really super Holger!  ?
>> >
>> > There was a conversation about this on x3d-public a few years back... We
>> > committed to adding it in X3D 4.1 and (if I recall correctly) also noted
>> > that adding a url field might enable usage of larger font files.
>> >
>> > I've attempted to capture this candidate specification change in a Mantis
>> > issue.  All review, feedback, and improvements are always welcome.
>> >
>> >    - Mantis 1490 FontStyle handling of font files and font libraries
>> >    - https://mantis.web3d.org/view.php?id=1490
>> >
>> > Description.
>> > A goal for X3D 4.1 is use of font files in FontStyle (see Mantis 0001464
>> > <https://mantis.web3d.org/view.php?id=1464>).
>> >
>> > Addition of individual-font files might be accomplished by listing the
>> > font file name in the FontStyle 'family' field.
>> >
>> > Referencing different fonts in a single combined font library file may
>> > require an additional field, for example 'url'. In general the use of a
>> > font library may be preferred, but repeatedly run-time retrieval of a font
>> > library is not desirable, since the file might be quite large and rarely
>> > changing. This might be noted in the specification prose, e.g.
>> >
>> > - "MFString [in,out] url [] [URI]"
>> > - "The family field may list a specific font file. A font listed in the
>> > family field may be provided by a corresponding font library."
>> > - "The url field may refer to a font library. Font libraries can be used
>> > by multiple FontStyle nodes in a scene and need only be loaded once per
>> > session."
>> >
>> > Support levels: add "Level 2, FontStyle, support for font files in family
>> > field and support for font libraries via url field ."
>> >
>> > Security, licensing, and copyright/usage issues are handled via the
>> > exposure of the font file itself. If retrievable (locally or online) then
>> > proper access is presumably handled separately.
>> >
>> > Additional information.
>> > - X3D 4.1 (draft) Architecture, 15 Text component, 15.4.1 FontStyle
>> > -
>> > https://www.web3d.org/specifications/X3Dv4/ISO-IEC19775-1v4-IS/Part01/components/text.html#FontStyle
>> >
>> > - X3D 4.1 (draft) Architecture, 15 Text component, 15.4.2 Text
>> > -
>> > https://www.web3d.org/specifications/X3Dv4/ISO-IEC19775-1v4-IS/Part01/components/text.html#Text
>> >
>> > - X3D 4.1 (draft) Architecture, 15 Text component, 15.5 Support levels
>> > -
>> > https://www.web3d.org/specifications/X3Dv4/ISO-IEC19775-1v4-IS/Part01/components/text.html#SupportlLevels
>> >
>> > Have fun with X3D Text!   :)
>> >
>> >
>> > 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 <x3d-public-bounces at web3d.org <mailto:x3d-public-bounces at web3d.org>> on behalf of Holger
>> > Seelig via x3d-public <x3d-public at web3d.org <mailto:x3d-public at web3d.org>>
>> > *Sent:* Monday, February 24, 2025 2:48 AM
>> > *To:* X3D <x3d-public at web3d.org <mailto:x3d-public at web3d.org>>
>> > *Cc:* Holger Seelig <holger.seelig at yahoo.de <mailto:holger.seelig at yahoo.de>>
>> > *Subject:* Re: [x3d-public] Open dyslexic and/or (unfortunately)
>> > comicsans fonts
>> >
>> > With X_ITE you can use a URL in the family field of a FontStyle node to
>> > specify a path to a custom font file. Provided you have one of these fonts,
>> > it should be very easy:
>> >
>> > <?xml version="1.0" encoding="UTF-8"?>
>> > <!DOCTYPE X3D PUBLIC "ISO//Web3D//DTD X3D 4.0//EN" "
>> > https://www.web3d.org/specifications/x3d-4.0.dtd">
>> > <X3D profile='Interchange' version='4.0' xmlns:xsd='
>> > http://www.w3.org/2001/XMLSchema-instance' xsd:noNamespaceSchemaLocation='
>> > https://www.web3d.org/specifications/x3d-4.0.xsd'>
>> >   <head>
>> >     <component name='Text' level='1'/>
>> >   </head>
>> >   <Scene>
>> >     <Transform DEF='Text'>
>> >       <Shape>
>> >         <Appearance>
>> >           <Material/>
>> >         </Appearance>
>> >         <Text
>> >             string='"3D Text"'>
>> >           <FontStyle
>> >               family='"path/to/your/font.otf", "SERIF"'/>
>> >         </Text>
>> >       </Shape>
>> >     </Transform>
>> >   </Scene>
>> > </X3D>
>> >
>> > Supported File Formats:
>> >
>> > https://create3000.github.io/x_ite/components/text/fontstyle/#supported-file-formats
>> >
>> > Best regards,
>> > Holger
>> >
>> > --
>> > Holger Seelig
>> > Leipzig, Germany
>> >
>> > holger.seelig at yahoo.de <mailto:holger.seelig at yahoo.de>
>> > https://create3000.github.io/x_ite/
>> >
>> > Am 24.02.2025 um 11:09 schrieb John Carlson via x3d-public <
>> > x3d-public at web3d.org <mailto:x3d-public at web3d.org>>:
>> >
>> > If someone knows how change the fonts of the standards to OpenDyslexic or
>> > ComicSans, that might be a great accessibility experiment.
>> > _______________________________________________
>> > 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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> 
> 
> 
> --
> Andreas Plesch
> Waltham, MA 02453
> _______________________________________________
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