[x3d-public] Recall--Re: X3D 4.0 specification problem: OrthoViewpoint.fieldOfView
John Carlson
yottzumm at gmail.com
Sun Jul 27 00:12:47 PDT 2025
Don, can you double check that you checked in the X3dToJava.xslt?
I have the most up-to-date version from sourceforge:
PS C:\Users\jcarl\www.web3d.org\x3d\stylesheets> svn-diff .\X3dToJava.xslt
PS C:\Users\jcarl\www.web3d.org\x3d\stylesheets>
Then there's this weird thing, which I don't get????
$ diff /c/Users/jcarl/www.web3d.org/x3d/stylesheets/X3dToJava.xslt
./X3dToJava.xslt
4629d4628
< ($parentElementName='OrthoViewpoint' and
$attributeName='fieldOfView') or
4814a4814
> ($parentElementName='OrthoViewpoint' and
$attributeName='fieldOfView') or
Git diff shows there was a blank added at the end of a line:
$ git diff X3dToJava.xslt
warning: in the working copy of 'src/main/lib/stylesheets/X3dToJava.xslt',
LF will be replaced by CRLF the next time Git touches it
diff --git a/src/main/lib/stylesheets/X3dToJava.xslt
b/src/main/lib/stylesheets/X3dToJava.xslt
old mode 100755
new mode 100644
index 1237d9eb9..957564ccd
--- a/src/main/lib/stylesheets/X3dToJava.xslt
+++ b/src/main/lib/stylesheets/X3dToJava.xslt
@@ -4626,6 +4626,7 @@ POSSIBILITY OF SUCH DAMAGE.
($parentElementName='MetadataFloat' and
$attributeName='value') or
($parentElementName='NavigationInfo' and
$attributeName='avatarSize') or
($parentElementName='NurbsTextureCoordinate' and
$attributeName='weight') or
+ ($parentElementName='OrthoViewpoint' and
$attributeName='fieldOfView') or
($parentElementName='ParticleSystem' and
($attributeName='colorKey' or $attributeName='texCoordKey')) or
($parentElementName='ScalarInterpolator' and
$attributeName='keyValue') or
($parentElementName='SplineScalarInterpolator' and
($attributeName='keyValue' or $attributeName='keyVelocity')) or
@@ -4811,7 +4812,6 @@ POSSIBILITY OF SUCH DAMAGE.
<xsl:when test="
($localFieldType='SFVec4f') or
($parentElementName='ClipPlane' and
$attributeName='plane') or
- ($parentElementName='OrthoViewpoint' and
$attributeName='fieldOfView') or
($parentElementName='TextureProjectorParallel' and
$attributeName='fieldOfView')">
<xsl:text>SFVec4f</xsl:text>
</xsl:when>
Also, please convert this Connectors.x3d to Java or see file produced from
X3dToJava.xslt. I will attach the Java and the X3D. I will try converting
to Java using X3DJSAIL.
It looks like something didn't get checked in?
On Fri, Jul 25, 2025 at 1:16 PM Don Brutzman <don.brutzman at gmail.com> wrote:
> Part of X3D Architecture 4.0 final decisions was to keep OrthoViewpoint
> fieldOfView with type MFFloat for backwards compatibility, rather than the
> more-strict (and more-correct) type SFVec4f.
>
> Apologies but this type change was not applied to X3dToJava.xslt and so
> the conversion you observed was erroneous. I have applied and checked in
> this change, it now works for your example.
>
> When diagnosing a problem like this, the Javadoc is always helpful. It
> shows three different methods for OrthoViewpoint setFieldOfView:
>
> -
> https://www.web3d.org/specifications/java/javadoc/org/web3d/x3d/jsail/Navigation/OrthoViewpoint.html#setFieldOfView(float%5B%5D)
> -
> https://www.web3d.org/specifications/java/javadoc/org/web3d/x3d/jsail/Navigation/OrthoViewpoint.html#setFieldOfView(org.web3d.x3d.jsail.fields.MFFloat)
> -
> https://www.web3d.org/specifications/java/javadoc/org/web3d/x3d/jsail/Navigation/OrthoViewpoint.html#setFieldOfView(java.util.ArrayList)
>
> Looking ahead, have added a goal TODO for X3DJSAIL that might flexibly
> handle reasonable variations like this.
>
> - *Under consideration.* Add utility methods for variable-length
> arguments (varargs
> <https://docs.oracle.com/javase/8/docs/technotes/guides/language/varargs.html>)
> to basic types.
> -
> https://docs.oracle.com/javase/8/docs/technotes/guides/language/varargs.html
>
> Thanks John for reporting this problem.
>
> all the best, Don
>
>
> On Fri, Jul 25, 2025 at 2:40 AM John Carlson via x3d-public <
> x3d-public at web3d.org> wrote:
>
>> Apparently, this got thrown in the forgotten pile? I'm not sure if I
>> have the latest message here. I guess the messages happened over the Xmas
>> holidays.
>>
>> X3DJSAIL is not compiling the setFieldOfView with 4 parameters,and my
>> MFFloat separate class is not emitting anything either!
>>
>> Details on SourceForge.
>>
>> Thanks for looking at this!
>>
>> So while this views in Sunrize, the Java generated from it fails to
>> produce XML or JSON that can immediately be seen (remove
>> OrthoViewpoint.fieldOfView to see).
>>
>>
>> https://github.com/create3000/Library/blob/main/Tests/Components/Shape/Connectors.x3d
>>
>> John
>>
>> On Fri, Dec 20, 2024 at 10:03 AM Brutzman, Donald (Don) (CIV) via
>> x3d-public <x3d-public at web3d.org> wrote:
>>
>>> [changed subject line to match topic]
>>>
>>> To be clear, no changes have been applied anywhere for changing the type
>>> from (MFFloat of length 4) to SFVec4f. Further we are not near consensus.
>>> Here are the fields:
>>>
>>> - ClipPlane plane is *SFVec4f*
>>> - TextureProjectorParallel fieldOfView is *SFVec4f*
>>> - OrthoViewpoint fieldOfView is *MFFloat of length 4* (which is not
>>> easily validatable, and inconsistent)
>>>
>>> Until our email discussion this past week, I had mistakenly thought that
>>> such a potential v4.1 change did not break backwards compatibility with any
>>> of our existing file encodings... Thanks for patiently helping to achieve
>>> that realization. The cause of this misunderstanding was due to omissions
>>> in the v3.3 ClassicVRML specification regarding use of brackets - they are
>>> not applied to SF types. We are now working on corrections with rationale
>>> and preliminary changes in the draft v4.0 ClassicVRML specification.
>>>
>>> - Mantis 1484: ClassicVRML field reference does not include proper
>>> SFVec examples
>>> - https://mantis.web3d.org/view.php?id=1484
>>>
>>> - X3D Classic VRML encoding version 4.0 draft, clause 5 Encoding of
>>> fields
>>> -
>>> https://www.web3d.org/specifications/X3Dv4Draft/ISO-IEC19776-2v4.0-WD1/Part02/EncodingOfFields.html
>>> - One of several suggested revisions in progress:
>>> - "Single-valued fields (SF types) are written as a list of one or
>>> more values, depending on the type. (For example, an SFVec3f type is a
>>> three-tuple array of three float values.) No square brackets ("[ ]") are
>>> written."
>>>
>>> The best time to fix this inconsistent typing would have been when we
>>> approved a number of corrections in X3D 4.0. We did not reach agreement
>>> during that long effort.
>>>
>>> The strict typing of X3D is very powerful. Given our long efforts to
>>> achieve a unified object model, there are very few inconsistencies...
>>> offhand, am unable to think of any others. Validatable fast parsing is
>>> also very powerful. We won't be breaking that by engineering hacks into
>>> the field grammars.
>>>
>>> This keeps us unchanged at your option (1) below, Michalis. Due to
>>> being unable to reconcile a change for an early X3D design choice (in
>>> version 3.2) for OrthoViewpoint fieldOfView: we live with this
>>> inconsistency, allowing the presence of undetected invalid content in
>>> models. Example errors:
>>>
>>> <OrthoViewpoint DEF='Error1' fieldOfView='0'/>
>>> <OrthoViewpoint DEF='Error2' fieldOfView='0 0'/>
>>> <OrthoViewpoint DEF='Error3' fieldOfView='0 0 1'/>
>>> <OrthoViewpoint DEF='Error5' fieldOfView='0 0 1 1 1'/>
>>>
>>> As before during X3D 4.0 review, I don't recommend this state of affairs
>>> but can live with it.
>>>
>>> If there is willingness to change, the only remaining path forward is
>>>
>>> - Agreeing to fix this type inconsistency in X3D 4.1, OrthoViewpoint
>>> fieldOfView becomes SFVec3f
>>> - VRML parsers support either form of encoding (perhaps adapting
>>> Doug's suggestion). For example
>>> - DEF Original3.2 OrthoViewpoint { fieldOfView [1, -1, 1, 1] } #
>>> with square brackets
>>> - DEF Revised4.x OrthoViewpoint { fieldOfView -1 -1 1 1 }
>>> # without square brackets
>>>
>>> Onward we go. Happy Holidays everyone.
>>>
>>>
>>> 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
>>> https://faculty.nps.edu/brutzman
>>>
>>>
>>>
>>> ------------------------------
>>> *From:* Michalis Kamburelis <michalis.kambi at gmail.com>
>>> *Sent:* Friday, December 20, 2024 12:34 AM
>>> *To:* Brutzman, Donald (Don) (CIV) <brutzman at nps.edu>
>>> *Cc:* GPU Group <gpugroup at gmail.com>; Extensible 3D (X3D) Graphics
>>> public discussion <x3d-public at web3d.org>; khyoo at chungbuk.ac.kr <
>>> khyoo at chungbuk.ac.kr>; Myeong Won Lee <myeongwonlee at gmail.com>
>>> *Subject:* Re: [x3d-public] X3D 4.0 specification problem:
>>> TextureProjectorparallel.fieldOfView
>>>
>>> Personally, I like Doug solution with "fieldOfView4f SFVec4f" .
>>>
>>> As for DRY -- indeed it would be perfect to not have 2 fields doing
>>> the same thing, but in the current situation we don't have a luxury of
>>> doing a perfect solution :) Next steps, in my order of preference:
>>>
>>> 1. Simply revert this change. Make OrthoViewport.fieldOfView again
>>> MFFloat.
>>>
>>> The problems introduced by this change are not worth the gain,
>>> IMHO. Changing OrthoViewport.fieldOfView to SFVec4f is a consistency
>>> improvement for a single field in single node. It's not worth now
>>> checking / changing encodings and APIs to make sure that everything
>>> that gets/sets MFFloat can also get/set SFVec4f.
>>>
>>> 2. Add 2nd field with SFVec4f, like "fieldOfView4f". Keep
>>> "fieldOfView" as MFFloat.
>>>
>>> I propose a modified version of Doug suggestion (different
>>> fallback order, because it seems more natural to check MFFloat count):
>>>
>>> - new field "fieldOfView4f SFVec4f -1 -1 -1 -1"
>>> - change existing "fieldOfView MFFloat" default to []
>>> - spec says:
>>> Authors: please use fieldOfView4f, consider fieldOfView deprecated.
>>> Implementors: if fieldOfView.count <> 0 then use fieldOfView,
>>> else use fieldOfView4f
>>>
>>> 3. (Please let's not do this :) ) Modify X3D classic encoding grammar
>>> to allow [ ] around SFVec4f values.
>>>
>>> I can see that Don may be leaning towards this (since you thought
>>> this is already how X3D classic encoding works a few days ago) but it
>>> would be a very unoptimal solution IMHO:
>>>
>>> - One, because it means escalating a small change into a big
>>> change. Changing "OrthoViewport.fieldOfView" is about one single field
>>> in single node. Changing X3D classic grammar means changing the
>>> grammar and parsing. And the grammar should be consistent, so it would
>>> likely spiral into allowing [ ] for other types as well, like SFVec3f.
>>>
>>> - The 2nd reason is that it's an incomplete fix anyway. While it
>>> will allow new browsers (that implement new grammar) to handle both
>>> old and new X3D models (whether author used [ ] or not aroud
>>> "OrthoViewport.fieldOfView")... But
>>>
>>> A. The old browsers (implementing original grammar) will not be
>>> able to read files using "OrthoViewpoint { fieldOfView -1 -1 1 1 }",
>>> they will throw parsing
>>> error exceptions. I understand it's a minor issue, old browsers are
>>> not supposed to handle X3D 4.1, but users do not like paying attention
>>> to version changes. Users assume (correctly!) that versions changes
>>> generally don't cause problems.
>>>
>>> B. We still have compatibility break if someone used PROTO with
>>> IS for "OrthoViewport.fieldOfView". This PROTO field type will need to
>>> change.
>>>
>>> C. We still have compatibility break for other APIs using X3D
>>> (like CGE Pascal API, but I suspect all other API like from Java etc.
>>> -- unless one introduces overloads to handle both types).
>>>
>>> Thanks for the discussion. Let's keep going toward a solution that is
>>> the best compromise :)
>>>
>>> Regards,
>>> Michalis
>>>
>>>
>>> czw., 19 gru 2024 o 20:26 Brutzman, Donald (Don) (CIV)
>>>
>>>
>>> <brutzman at nps.edu> napisał(a):
>>> >
>>> > Thanks for thinking about alternatives. In general, however, we don't
>>> repeat functionality, in accordance with DRY principles:
>>> >
>>> > Wikipedia: Don't repeat yourself
>>> >
>>> https://nam10.safelinks.protection.outlook.com/?url=https%3A%2F%2Fen.wikipedia.org%2Fwiki%2FDon%27t_repeat_yourself&data=05%7C02%7Cbrutzman%40nps.edu%7Ca798d8810015488b460008dd20d133db%7C6d936231a51740ea9199f7578963378e%7C0%7C0%7C638702806790110709%7CUnknown%7CTWFpbGZsb3d8eyJFbXB0eU1hcGkiOnRydWUsIlYiOiIwLjAuMDAwMCIsIlAiOiJXaW4zMiIsIkFOIjoiTWFpbCIsIldUIjoyfQ%3D%3D%7C60000%7C%7C%7C&sdata=EUA%2FyLVNpeDBd9%2FvGiI%2FBdWCee3S8PjV%2FsD9vDFO2U0%3D&reserved=0
>>> <https://en.wikipedia.org/wiki/Don't_repeat_yourself>
>>> >
>>> > 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
>>> https://faculty.nps.edu/brutzman
>>> >
>>> >
>>> >
>>> >
>>> > ________________________________
>>> > From: GPU Group <gpugroup at gmail.com>
>>> > Sent: Thursday, December 19, 2024 10:55 AM
>>> > To: Extensible 3D (X3D) Graphics public discussion <
>>> x3d-public at web3d.org>
>>> > Cc: Brutzman, Donald (Don) (CIV) <brutzman at nps.edu>; Michalis
>>> Kamburelis <michalis.kambi at gmail.com>; khyoo at chungbuk.ac.kr <
>>> khyoo at chungbuk.ac.kr>; Myeong Won Lee <myeongwonlee at gmail.com>
>>> > Subject: Re: [x3d-public] X3D 4.0 specification problem:
>>> TextureProjectorparallel.fieldOfView
>>> >
>>> > IDEA: _add_ another field with different name, with a sentinel value
>>> default
>>> > fieldOfView4f SFVec4f -1 -1 -1 -1
>>> > Then in run code, if that field is set at its default, use the
>>> original MFFloat field, else use the new SFVec4f field.
>>> > -Doug
>>> >
>>> >
>>> > On Wed, Dec 18, 2024 at 9:39 PM Michalis Kamburelis via x3d-public <
>>> x3d-public at web3d.org> wrote:
>>> >
>>> > Hi Don,
>>> >
>>> > AD A -
>>> >
>>> > No, when writing the SFVec4f in X3D classic encoding, the square
>>> > brackets "[ ... ]" cannot be used. I believe my understanding matches
>>> > both the spec and all existing X3D implementations.
>>> >
>>> > 1. The example you noticed (on
>>> >
>>> https://www.web3d.org/documents/specifications/19776-2/V3.3/Part02/EncodingOfFields.html#SFVec4f
>>> > ) ... shows MFVec4f, not SFVec4f .
>>> >
>>> > It's indeed a bit misleading, as the spec section titled "5.20
>>> > SFVec3f and MFVec3f" describes both MF- and SF- variants. And the
>>> > example "fooVec3d [ 1.000000000001 42 666.35357878 32.6, 7 94
>>> > 0.100000000007 143.998 ]" lacks any annotation. Adding there a
>>> > description would help: "This is an example of MFVec4f in classic
>>> > encoding, fooVec3d contains here two 4-dimensional vectors." .
>>> >
>>> > 2. On the same page, the text higher makes it clear that "square
>>> > brackets" are used for multiple-value fields: """Multiple-valued
>>> > fields are written as an ordered list of values enclosed in square
>>> > brackets and separated by whitespace."""
>>> >
>>> > 3. The grammar on
>>> >
>>> https://www.web3d.org/documents/specifications/19776-2/V3.3/Part02/grammar.html
>>> > confirms it:
>>> >
>>> > """
>>> > mffloatValue ::=
>>> > sffloatValue |
>>> > [ ] |
>>> > [ sffloatValues ] ;
>>> >
>>> > ....
>>> >
>>> > sfvec4fValue ::=float float float float ;
>>> > """"
>>> >
>>> > No square brackets for sfvec4fValue . (And that's good I think; square
>>> > brackets are consistently used in X3D classic encoding for lists of
>>> > values.)
>>> >
>>> > I do find the grammar very helpful to resolve such questions :) It's
>>> > unambiguous, and implementations (using my own) follow it literally.
>>> >
>>> > So, I think my concern still stands. Changing
>>> > OrthoViewport.fieldOfView type (MFFloat -> SFVec4f) would break
>>> > parsing of all the models in X3D classic encoding (and VRML 2.0) that
>>> > specify value of this field. They use right now square brackets [ .. ]
>>> > (necessary for MFFloat with > 1 value), which are not allowed for
>>> > SFVec4f.
>>> >
>>> > I honestly don't think there's a way to avoid it, except reverting
>>> > this spec change. I cannot change in our implementation
>>> > OrthoViewport.fieldOfView to SFVec4f -- I have users using classic
>>> > encoding, and VRML 2.0 too, we cannot really break it. And maintaining
>>> > exceptional treatment in the parser (to allow both MFFloat and
>>> > SFVec4f) is not maintainable, we cannot have special rules like this
>>> > (that depend on node and field name) at the parser level.
>>> >
>>> > I know that we could change the grammar (to allow [ ... ] in SFVec4f)
>>> > but IMHO we should not change the grammar (which will complicate
>>> > parsing) just to account this one single exceptional change to one
>>> > field in one node.
>>> >
>>> > AD B - No, I didn't describe any special handling in our parser. And
>>> > such exceptions during parsing would be really hard to maintain, I
>>> > deliberately don't want them. Parser should not have any special rules
>>> > for specific nodes or fields -- this makes parser code more obvious.
>>> >
>>> > On the contrary -- we parse OrthoViewport.fieldOfView as MFFloat
>>> > now. Only later (after parsing) we just look at the count of MFFloat.
>>> > When it's less than 4, we treat the remaining numbers as if they were
>>> > default. But this is nice "local" code near OrthoViewport.fieldOfView
>>> > logic. It's *not* part of the parser.
>>> >
>>> > Regards,
>>> > Michalis
>>> >
>>> > czw., 19 gru 2024 o 03:06 Brutzman, Donald (Don) (CIV)
>>> > <brutzman at nps.edu> napisał(a):
>>> > >
>>> > > Thanks for looking at this Michalis.
>>> > >
>>> > > A. Sorry but I'm not clear about what you are saying... Went to
>>> look at the existing ClassicVRML encoding and it is showing [square
>>> brackets] for SFVec4f:
>>> > >
>>> > > X3D Classic VRML encoding, clause 5 encoding of fields, 5.22 SFVec4f
>>> and MFVec4f
>>> > >
>>> https://www.web3d.org/documents/specifications/19776-2/V3.3/Part02/EncodingOfFields.html#SFVec4f
>>> > >
>>> > > The SFVec4f field specifies a four-dimensional (4D) single-precision
>>> vector. An MFVec4f field specifies zero or more 4D single-precision
>>> vectors. SFVec4f's and MFVec4f's are encoded as four ISO C floating point
>>> values (see ISO/IEC 9899) separated by whitespace.
>>> > > EXAMPLE
>>> > > fooVec3f [ 1 42 666 -43.8, 7 94 0 0.0001 ]
>>> > >
>>> > > ... And so am expecting your SFVec4f example would look the same,
>>> with [square brackets] around numeric values. Please advise what you
>>> think.
>>> > >
>>> > > OrthoViewpoint { fieldOfView [ -1 -1 1 1 ] }
>>> > >
>>> > >
>>> > > B. Depending on that, am next wondering... you describe how the
>>> current MFFloat approach already requires additional special handling by
>>> your parser if an incorrect number of values is encountered. If there is a
>>> difference regarding [square brackets] for SFVec4f then maybe a parser
>>> adjustment for that might be possible too... Or, even if they are the same,
>>> maybe just keeping your error-handling parser for v3.3 content the same
>>> (also for backwards reliability) is a good idea also.
>>> > >
>>> > > C. We are currently working on ClassicVRML Encoding spec for v4.0
>>> now, so if any problems are found then we can resolve them.
>>> > >
>>> > > D. I found several problems with the Grammar... Dick and I also
>>> discussed them yesterday. When time permits, will post about that soon.
>>> > >
>>> > > Have fun with X3D ClassicVRML Encoding! 🙂
>>> > >
>>> > >
>>> > > 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
>>> https://faculty.nps.edu/brutzman
>>> > >
>>> > >
>>> > >
>>> > >
>>> > > ________________________________
>>> > > From: x3d-public <x3d-public-bounces at web3d.org> on behalf of
>>> Michalis Kamburelis via x3d-public <x3d-public at web3d.org>
>>> > > Sent: Wednesday, December 18, 2024 5:37 PM
>>> > > To: Extensible 3D (X3D) Graphics public discussion <
>>> x3d-public at web3d.org>
>>> > > Cc: Michalis Kamburelis <michalis.kambi at gmail.com>;
>>> khyoo at chungbuk.ac.kr <khyoo at chungbuk.ac.kr>; Myeong Won Lee <
>>> myeongwonlee at gmail.com>
>>> > > Subject: Re: [x3d-public] X3D 4.0 specification problem:
>>> TextureProjectorparallel.fieldOfView
>>> > >
>>> > > The change of OrthoViewpoint.fieldOfView from MFFloat to SFVec4f
>>> > > breaks compatibility (badly) for X3D classic encoding, from what I
>>> can
>>> > > see.
>>> > >
>>> > > Previously (when OrthoViewpoint.fieldOfView is MFFloat, so in X3D <=
>>> > > 4.0 and VRML 2.0) this was valid:
>>> > >
>>> > > OrthoViewpoint { fieldOfView [ -1 -1 1 1 ] }
>>> > >
>>> > > And this was "undefined how it works (spec doesn't say what happens
>>> > > for < 4 values), but at least parsing was OK" (CGE made some effort
>>> to
>>> > > tolerate it):
>>> > >
>>> > > OrthoViewpoint { fieldOfView [ -1 -1 ] }
>>> > >
>>> > > Now (when OrthoViewpoint.fieldOfView is SFVec4f) both above are
>>> > > invalid, at parsing. One has to write this:
>>> > >
>>> > > OrthoViewpoint { fieldOfView -1 -1 1 1 }
>>> > >
>>> > > ... but the new form is invalid if loaded into a browser that expects
>>> > > OrthoViewpoint.fieldOfView to be old MFFloat.
>>> > >
>>> > > And, before anyone suggests this: It's not reasonable for X3D
>>> browsers
>>> > > to define OrthoViewpoint.fieldOfView with one type for X3D >= 4.1,
>>> and
>>> > > another type for older X3D versions. At least I cannot imagine
>>> > > maintaining this exceptional behavior throughout the codebase :) We
>>> > > need to have a one definition of OrthoViewpoint with one type for
>>> > > fieldOfView, otherwise we cause a big complication (also for
>>> > > developers using our API).
>>> > >
>>> > > So, I'm a bit baffled what to do. If I change
>>> > > OrthoViewpoint.fieldOfView to SFVec4f, I *will* break some X3D models
>>> > > for users and I will get bugreports about it. If I don't, I will not
>>> > > be compatible with X3D 4.1. For now, I choose the latter.
>>> > >
>>> > > Regards,
>>> > > Michalis
>>> > >
>>> > > czw., 19 gru 2024 o 01:42 John Carlson via x3d-public
>>> > > <x3d-public at web3d.org> napisał(a):
>>> > >
>>> > >
>>> > >
>>> > > >
>>> > > > I’m imagining there will be changes to C++ SAI. Once new types
>>> are in place I can attempt to test. I suggest getting an X3DUOM out soon,
>>> so I can regenerate my fieldTypes.js file, which affects all my serializers.
>>> > > >
>>> > > > No one is using my serializers that I know of, so this particular
>>> change won’t probably affect anyone. They would have to update, and I
>>> don’t currently recommend that.
>>> > > >
>>> > > > Bug reports are welcome:
>>> > > >
>>> > > >
>>> https://nam10.safelinks.protection.outlook.com/?url=https%3A%2F%2Fgithub.com%2Fcoderextreme%2FX3DJSONLD%2Fissues&data=05%7C02%7Cbrutzman%40nps.edu%7Ca798d8810015488b460008dd20d133db%7C6d936231a51740ea9199f7578963378e%7C0%7C0%7C638702806790133840%7CUnknown%7CTWFpbGZsb3d8eyJFbXB0eU1hcGkiOnRydWUsIlYiOiIwLjAuMDAwMCIsIlAiOiJXaW4zMiIsIkFOIjoiTWFpbCIsIldUIjoyfQ%3D%3D%7C60000%7C%7C%7C&sdata=RD2m3DWAfH1d5QDVg9p4%2FNlXnkSInA%2FxG5bnd%2F1pHIM%3D&reserved=0
>>> <https://github.com/coderextreme/X3DJSONLD/issues>
>>> > > >
>>> > > >
>>> > > > AFAIK, this does not affect X3D JSON, since MFFloat and SFVec4f
>>> are represented by arrays.
>>> > > >
>>> > > > If you recommend tweaking X3DUOM before your release, I can see
>>> what I can do, but it’s not currently a priority for me. Reading the X_ITE
>>> component into Blender is higher priority.
>>> > > >
>>> > > > Someone speaking up can change the priority.
>>> > > >
>>> > > > John
>>> > > >
>>> > > > On Wed, Dec 18, 2024 at 6:00 PM Brutzman, Donald (Don) (CIV) via
>>> x3d-public <x3d-public at web3d.org> wrote:
>>> > > >>
>>> > > >> During a specification editors' meeting yesterday, Dick and I
>>> made another step forward.
>>> > > >>
>>> > > >> Mantis 1398: OrthoViewpoint fieldOfView type needs to be SFVec4f,
>>> not MFFloat
>>> > > >> https://mantis.web3d.org/view.php?id=1398
>>> > > >>
>>> > > >> namely
>>> > > >>
>>> > > >> If specialty methods for homogeneous transformations (or other
>>> operations) are needed by SAI implementations, they can receive specialized
>>> definitions to match.
>>> > > >> It is important to remember that (a) no nodes currently use
>>> homogenous coordinates, and (b) ClipPlane definition of a half-plane is
>>> different than the two parallel-projection extents.
>>> > > >> A graceful approach not requiring implementation changes might be
>>> adding prose to Clause 5 field definitions noting alternate usages may
>>> occur. For example, appended to the fist sentence, "or other usage of a
>>> 4-tuple."
>>> > > >>
>>> > > >> We applied that change in draft X3D 4.1 Architecture, also
>>> committed into git and pushed online.
>>> > > >>
>>> > > >> 5.3.20 SFVec4d and MFVec4d
>>> > > >>
>>> https://www.web3d.org/specifications/X3Dv4Draft/ISO-IEC19775-1v4.1-CD//Part01/fieldTypes.html#SFVec4dAndMFVec4d
>>> > > >> 5.3.21 SFVec4f and MFVec4f
>>> > > >>
>>> https://www.web3d.org/specifications/X3Dv4Draft/ISO-IEC19775-1v4.1-CD//Part01/fieldTypes.html#SFVec4fAndMFVec4f
>>> > > >>
>>> > > >> ==========================
>>> > > >> 5.3.20 SFVec4d and MFVec4d
>>> > > >> The SFVec4d field or event specifies a three-dimensional (3D)
>>> homogeneous vector, or other usage of a 4-tuple. An MFVec4d field or event
>>> specifies zero or more SFVec4d values. 3D homogeneous vectors. SFVec4d's
>>> and MFVec4d's are represented as a 4-tuple of double-precision floating
>>> point values (see 5.3.4 SFDouble and MFDouble). The allowable form for a
>>> double-precision floating point number is defined in the specific encoding.
>>> > > >> The default value of an uninitialized SFVec4d field is (0 0 0 1).
>>> The default value of an MFVec4d field is the empty list.
>>> > > >> 5.3.21 SFVec4f and MFVec4f
>>> > > >> The SFVec4f field or event specifies a three-dimensional (3D)
>>> homogeneous vector, or other usage of a 4-tuple. An MFVec4f field or event
>>> specifies zero or more SFVec4f values. 3D homogeneous vectors. SFVec4f's
>>> and MFVec4f's are represented as a 4-tuple of single-precision floating
>>> point values (see 5.3.5 SFFloat and MFFloat). The allowable form for a
>>> single-precision floating point number is defined in the specific encoding.
>>> > > >> The default value of an uninitialized SFVec4f field is (0 0 0 1).
>>> The default value of an MFVec4f field is the empty list.
>>> > > >> ==========================
>>> > > >>
>>> > > >> If anyone can think of any reason not to restrict validation of
>>> OrthoViewpoint fieldOfView to SFVec4f, instead of an MFFloat array of
>>> length 4, please speak up. Am hoping to apply this change next to
>>> validation tools next, improving quality assurance and author confidence
>>> that a model is valid. Avoiding run-time errors and maintaining
>>> consistency, with no harm to existing X3D models or implementations, is
>>> important.
>>> > > >>
>>> > > >> Have fun with high-quality X3D! 🙂
>>> > > >>
>>> > > >>
>>> > > >> 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
>>> https://faculty.nps.edu/brutzman
>>> > > >>
>>> > > >>
>>> > > >>
>>> > > >>
>>> > > >> ________________________________
>>> > > >> From: Brutzman, Donald (Don) (CIV) <brutzman at nps.edu>
>>> > > >> Sent: Friday, December 13, 2024 1:14 PM
>>> > > >> To: Holger Seelig <holger.seelig at yahoo.de>; X3D <
>>> x3d-public at web3d.org>
>>> > > >> Cc: khyoo at chungbuk.ac.kr <khyoo at chungbuk.ac.kr>; Myeong Won Lee <
>>> myeongwonlee at gmail.com>
>>> > > >> Subject: Re: [x3d-public] X3D 4.0 specification problem:
>>> TextureProjectorparallel.fieldOfView
>>> > > >>
>>> > > >> Excellent question, thanks for asking Holger.
>>> > > >>
>>> > > >> This issue has been carefully tracked and regularly revisited
>>> since July 2022.
>>> > > >>
>>> > > >> Mantis 1398: OrthoViewpoint fieldOfView type needs to be SFVec4f,
>>> not MFFloat
>>> > > >> https://mantis.web3d.org/view.php?id=1398
>>> > > >> Mantis 1468: must SFVec4f/SFVec4d fields be homogeneous?
>>> > > >> https://mantis.web3d.org/view.php?id=1468
>>> > > >>
>>> > > >> The X3D Working Group was unable to reach consensus on this issue
>>> prior to conclusion of version 4.0, unfortunately. Dick Puk and I took a
>>> close look at this recently too. Here is a synopsis of the Mantis issues.
>>> > > >>
>>> > > >> I advocate use of SFVec4f for all parallel fieldOfView values
>>> because it is the strictest appropriate datatype that can validate content.
>>> Retaining the legacy MFFloat type definition for fieldOfView allows 3d
>>> models (produced by humans or tools) to define arrays of illegal length,
>>> making failures mysterious. Conceptual consistency is important too.
>>> > > >>
>>> > > >> Reviewing the Mantis issues, additional concerns included:
>>> > > >>
>>> > > >> Incompatibility with prior X3D implementations. Since a 4-tuple
>>> content value is a valid MFFloat array, I'm not seeing any backwards
>>> incompatibility if a prior X3D 3.3 implementation encounters the four
>>> values of a SFVec4f array. There are no representation problems since
>>> value syntax is compatible for our various encodings as well.
>>> > > >>
>>> > > >> SFVec4f fields are actually not homogenous coordinates. The spec
>>> uses the word "homogenous" when referring to
>>> > > >>
>>> > > >> X3D4 Architecture, Clause 5 Field type reference, 5.3.20 SFVec4d
>>> and MFVec4d
>>> > > >>
>>> https://www.web3d.org/specifications/X3Dv4/ISO-IEC19775-1v4-IS/Part01/fieldTypes.html#SFVec4dAndMFVec4d
>>> > > >> "The SFVec4f field or event specifies a three-dimensional (3D)
>>> homogeneous vector." (and similarly for SFVec4d, SFVec4f and MFVec4f).
>>> > > >> However none of these fields are mathematically homogeneous, see
>>> > > >>
>>> https://nam10.safelinks.protection.outlook.com/?url=https%3A%2F%2Fen.wikipedia.org%2Fwiki%2FHomogeneous_coordinates&data=05%7C02%7Cbrutzman%40nps.edu%7Ca798d8810015488b460008dd20d133db%7C6d936231a51740ea9199f7578963378e%7C0%7C0%7C638702806790151701%7CUnknown%7CTWFpbGZsb3d8eyJFbXB0eU1hcGkiOnRydWUsIlYiOiIwLjAuMDAwMCIsIlAiOiJXaW4zMiIsIkFOIjoiTWFpbCIsIldUIjoyfQ%3D%3D%7C60000%7C%7C%7C&sdata=%2B0692Ipq84A8Mo8IxSIa9LaK8DV1PD%2B9nMWL%2FjvYUbg%3D&reserved=0
>>> <https://en.wikipedia.org/wiki/Homogeneous_coordinates>
>>> > > >>
>>> https://nam10.safelinks.protection.outlook.com/?url=https%3A%2F%2Fen.wikipedia.org%2Fwiki%2FHomogeneous_coordinates%23%2Fmedia%2FFile%3ARationalBezier2D.svg&data=05%7C02%7Cbrutzman%40nps.edu%7Ca798d8810015488b460008dd20d133db%7C6d936231a51740ea9199f7578963378e%7C0%7C0%7C638702806790164107%7CUnknown%7CTWFpbGZsb3d8eyJFbXB0eU1hcGkiOnRydWUsIlYiOiIwLjAuMDAwMCIsIlAiOiJXaW4zMiIsIkFOIjoiTWFpbCIsIldUIjoyfQ%3D%3D%7C60000%7C%7C%7C&sdata=WDz40uRYwtPE3R%2FLIFURKLUaHvA%2BcuK%2BQIdfIwLebb0%3D&reserved=0
>>> <https://en.wikipedia.org/wiki/Homogeneous_coordinates#/media/File:RationalBezier2D.svg>
>>> > > >> Of related note is that ClipPlane 4-tuple "plane" field is also
>>> SFVec4f.
>>> > > >>
>>> https://www.web3d.org/specifications/X3Dv4/ISO-IEC19775-1v4-IS/Part01/components/rendering.html#ClipPlane
>>> > > >>
>>> > > >> All review welcome, hopefully I have correctly synopsized all
>>> concerns.
>>> > > >>
>>> > > >> I think it would be beneficial to resolve this issue by reaching
>>> consensus and applying remedies as follow.
>>> > > >>
>>> > > >> Omitting the over-strict word "homogenous" from the four SF/MF
>>> Vec 4f/4d definitions in future X3D 4.1 prose,
>>> > > >> Updating future X3D 4.1 prose to use SFVec4f for
>>> TextureProjectorParallel fieldOfView,
>>> > > >> Using SFVec4f in X3D 4.0 DTD, Schema, X3DUOM validation and X3D
>>> Tooltips, since that type strictly confirms fieldOfView correctness with no
>>> backwards compatibility problems.
>>> > > >>
>>> > > >> Is consensus now possible? Thanks for all careful consideration.
>>> > > >>
>>> > > >> 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
>>> https://faculty.nps.edu/brutzman
>>> > > >>
>>> > > >>
>>> > > >>
>>> > > >>
>>> > > >> ________________________________
>>> > > >> From: Holger Seelig <holger.seelig at yahoo.de>
>>> > > >> Sent: Friday, December 13, 2024 11:29 AM
>>> > > >> To: X3D <x3d-public at web3d.org>
>>> > > >> Cc: Brutzman, Donald (Don) (CIV) <brutzman at nps.edu>;
>>> khyoo at chungbuk.ac.kr <khyoo at chungbuk.ac.kr>; Myeong Won Lee <
>>> myeongwonlee at gmail.com>
>>> > > >> Subject: Re: [x3d-public] X3D 4.0 specification problem: upVector
>>> field for TextureProjector, TextureProjectorParallel
>>> > > >>
>>> > > >> I just realised that TextureProjectorparallel.fieldOfView is of
>>> type SFVec4f, but OrthoViewpoint.fieldOfView is of type MFFloat.
>>> > > >>
>>> > > >> Which of the two is better?
>>> > > >>
>>> > > >> OrthoViewpoint is definitely older.
>>> > > >>
>>> > > >> I think of SFVec4f as a mathematical 4d vector.
>>> > > >>
>>> > > >>
>>> https://www.web3d.org/documents/specifications/19775-1/V4.0/Part01/components/textureProjection.html#TextureProjectorParallel
>>> > > >>
>>> https://www.web3d.org/documents/specifications/19775-1/V4.0/Part01/components/navigation.html#OrthoViewpoint
>>> > > >>
>>> > > >> Best regards,
>>> > > >> Holger
>>> > > >>
>>> > > >> --
>>> > > >> Holger Seelig
>>> > > >> Leipzig, Germany
>>> > > >>
>>> > > >> holger.seelig at yahoo.de
>>> > > >>
>>> https://nam10.safelinks.protection.outlook.com/?url=https%3A%2F%2Fcreate3000.github.io%2Fx_ite%2F&data=05%7C02%7Cbrutzman%40nps.edu%7Ca798d8810015488b460008dd20d133db%7C6d936231a51740ea9199f7578963378e%7C0%7C0%7C638702806790176380%7CUnknown%7CTWFpbGZsb3d8eyJFbXB0eU1hcGkiOnRydWUsIlYiOiIwLjAuMDAwMCIsIlAiOiJXaW4zMiIsIkFOIjoiTWFpbCIsIldUIjoyfQ%3D%3D%7C60000%7C%7C%7C&sdata=LboRmmKHHvcVGr3DesWxfIea4ahYZNkm8bj0JQ%2FTXrE%3D&reserved=0
>>> <https://create3000.github.io/x_ite/>
>>> > > >>
>>> > > >> Am 08.12.2024 um 05:21 schrieb Brutzman, Donald (Don) (CIV) via
>>> x3d-public <x3d-public at web3d.org>:
>>> > > >>
>>> > > >> However
>>> > > >>
>>> > > >>
>>> > > >> _______________________________________________
>>> > > >> x3d-public mailing list
>>> > > >> x3d-public at web3d.org
>>> > > >> http://web3d.org/mailman/listinfo/x3d-public_web3d.org
>>> > > >
>>> > > > _______________________________________________
>>> > > > x3d-public mailing list
>>> > > > x3d-public at web3d.org
>>> > > > http://web3d.org/mailman/listinfo/x3d-public_web3d.org
>>> > >
>>> > > _______________________________________________
>>> > > x3d-public mailing list
>>> > > x3d-public at web3d.org
>>> > > http://web3d.org/mailman/listinfo/x3d-public_web3d.org
>>> >
>>> > _______________________________________________
>>> > x3d-public mailing list
>>> > x3d-public at web3d.org
>>> > http://web3d.org/mailman/listinfo/x3d-public_web3d.org
>>> _______________________________________________
>>> x3d-public mailing list
>>> x3d-public at web3d.org
>>> http://web3d.org/mailman/listinfo/x3d-public_web3d.org
>>>
>> _______________________________________________
>> x3d-public mailing list
>> x3d-public at web3d.org
>> http://web3d.org/mailman/listinfo/x3d-public_web3d.org
>>
>
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