[x3d-public] Fw: ProtoInstance USE without name

John Carlson yottzumm at gmail.com
Sun Nov 29 10:46:49 PST 2020 

Everyone please remember this conversation. Or perhaps put a link to this
thread on a website which discusses USE and name tradeoffs for nodes.

There's another thread somewhere on the same ProtoInstance topic, if anyone
cares to look.

No changes to JSON Schema that I know of required!

I believe there are still some statements which may have both USE and
name.   Those are OK, and noted.

Thanks, guys!

John

On Sun, Nov 29, 2020 at 12:24 PM Andreas Plesch <andreasplesch at gmail.com>
wrote:

> Some results of testing browsers:
>
> freeWrl: A and B works, C does not
> InstantPlayer: A and C renders, B does not, warning: "obligatory name is
> missing"; no sound in any on my system
> view3dscene: A, B and C work, no warnings in any.
> Octaga: A,B and C work, no warnings in any.
>
> In addition, I replaced "Script" with "Group" in C, with the same results
> in all browsers. This indicates that some browsers essentially ignore the
> Node type in a xml encoded USE node, following the VRML style of USE.
>
> [ So, in the XML encoding, we could have had a <USE name="DEFname" />
> construct which may have been discussed but was decided against, perhaps
> for reasons of validation. ]
>
> Only InstantPlayer requires the name attribute in a USE ProtoInstance,
> indicating a gap in the xml specification. While requiring the name
> attribute would be cleaner, in my view, it would break backward
> compatibility. Therefore explicitly USE without name for ProtoInstances
> makes the most sense to me. This would make InstantPlayer a little
> non-compliant.
>
> Cheers, -Andreas
>
>
>
> On Sun, Nov 29, 2020 at 10:00 AM Christoph Valentin <
> christoph.valentin at gmx.at> wrote:
>
>> The archive has been updated.
>>
>> . Removed the unused prototype
>>  two additional editorial corrections
>>
>>
>> to be crystal clear: the optimum would be to have a clear X3D standard
>> and to remove the workaround forever.
>>
>> @all: do other users have similar experiences with ProtoInstances, DEF
>> and USE? I am not the only user of X3D, am I?
>>
>> kr
>>
>>
>> *Gesendet:* Sonntag, 29. November 2020 um 15:39 Uhr
>> *Von:* "Christoph Valentin" <christoph.valentin at gmx.at>
>> *An:* "Andreas Plesch" <andreasplesch at gmail.com>
>> *Cc:* "X3D Graphics public mailing list" <x3d-public at web3d.org>
>> *Betreff:* Re: [x3d-public] ProtoInstance USE without name
>> Hi Andreas,
>>
>> The MoosTrigger can be deleted. I forgot it there, sorry (it would be
>> used for MU capability). I will correct asap.
>>
>> The only theory I have is that the external behaviour of scripts and
>> protos regarding the event cascade is very similar. Both have fields that
>> can be arbitrarily defined. So a reference to a script can hold a reference
>> to a ProtoInstance.
>>
>> Sorry I am not a Browser developer, but I am a (potential) user of X3D,
>> dont know so much about X3D internals. It could even be an intention of the
>> standard.
>>
>> kr
>>
>> --
>> Diese Nachricht wurde von meinem Android Mobiltelefon mit GMX Mail
>> gesendet.
>> Am 29.11.20, 15:24 schrieb Andreas Plesch <andreasplesch at gmail.com>:
>>>
>>> Hi Christoph,
>>>
>>> The Pig proto is using a "Moostrigger" proto. Should the Mosstrigger
>>> proto be included in the archive, or can it be ignored, eg. commented out ?
>>>
>>> I am struggling to understand how Version C, the Script workaround,
>>> could work:
>>>
>>> <!-- the second pig , version C - ProtoInstance WITHOUT name -->
>>>         <Transform translation='3 0 0' rotation='0 1 0 -1.57'>
>>>             <Script USE="ThePig"/>
>>>         </Transform>
>>>
>>> and the ThePig DEF is:
>>>
>>> <ProtoInstance DEF="ThePig" name='Pig'/>
>>>
>>> So the ThePig DEF is not a Script node. ( And the Pig proto is of Group
>>> type. ). It seems like it is just a coincidence that it works with
>>> BSContact. Perhaps BSContact somehow treats all ProtoInstances as Scripts ?
>>>
>>> Do  you have a theory why the workaround actually works with some
>>> browsers ?
>>>
>>> Thanks, Andreas
>>>
>>>
>>> On Sat, Nov 28, 2020 at 3:46 PM Andreas Plesch <andreasplesch at gmail.com>
>>> wrote:
>>>
>>>> Thanks, I will take a look.
>>>>
>>>> ---on the phone---
>>>>
>>>> On Sat, Nov 28, 2020, 9:17 AM Christoph Valentin <
>>>> christoph.valentin at gmx.at> wrote:
>>>>
>>>>> Hi Andreas,
>>>>>
>>>>> I felt free to provide an example scene in three flavors.
>>>>>
>>>>> The prototype renders a little pig that says "Eatme!", when you touch
>>>>> it (in remembrance of Douglas Adams)
>>>>>
>>>>> Version A: <ProtoInstance USE="xxx" name="yyy"/>    WITH name
>>>>> attribute - standards compliant
>>>>> Version B: <ProtoInstance USE="xxx"/>  WITHOUT name attribute
>>>>> Version C: <Script USE="xxx"/>  WORKAROUND - works for all browsers
>>>>>
>>>>> I tested with BS Contact --- he can cope with all three versions.
>>>>>
>>>>> Download the .zip file at
>>>>> https://lc-soc-lc.at/experimental/ProtoInstanceWithUSE/     I provide
>>>>> it by a GPLv3.
>>>>>
>>>>> Feed Back welcome. You may take it and give it to your benchmark
>>>>> tests, if you like.
>>>>>
>>>>> Kind regards,
>>>>> Christoph
>>>>>
>>>>>
>>>>> *Gesendet:* Dienstag, 24. November 2020 um 00:30 Uhr
>>>>> *Von:* "Andreas Plesch" <andreasplesch at gmail.com>
>>>>> *An:* "Christoph Valentin" <christoph.valentin at gmx.at>
>>>>> *Cc:* "X3D Graphics public mailing list" <x3d-public at web3d.org>
>>>>> *Betreff:* Re: [x3d-public] ProtoInstance USE without name
>>>>> Hi Christoph,
>>>>>
>>>>> thanks, interesting. Perhaps it will be useful to try a USE
>>>>> ProtoInstance in a very simple scene, in multiple browsers.
>>>>>
>>>>> -Andreas
>>>>>
>>>>> On Mon, Nov 23, 2020 at 1:01 PM Christoph Valentin <
>>>>> christoph.valentin at gmx.at> wrote:
>>>>>
>>>>>>
>>>>>> Hi
>>>>>>
>>>>>> This bug is common to many X3D players (even classical non-WebGL X3D
>>>>>> players).
>>>>>>
>>>>>> I was used to use following workaround, which worked for all relevant
>>>>>> players:
>>>>>>
>>>>>> If I want to USE a DEFd ProtoInstance, I will actually instantiate a
>>>>>> <Script> node with USE.
>>>>>>
>>>>>> KR,
>>>>>> Christoph
>>>>>>
>>>>>> *Gesendet:* Montag, 23. November 2020 um 00:00 Uhr
>>>>>> *Von:* "Andreas Plesch" <andreasplesch at gmail.com>
>>>>>> *An:* "X3D Graphics public mailing list" <x3d-public at web3d.org>
>>>>>> *Betreff:* [x3d-public] ProtoInstance USE without name
>>>>>> Looking at why the old Prototypes for HAnim did not work properly for
>>>>>> x3dom, I found that the xml examples typically have a ProtoInstance
>>>>>> statement with a USE attribute but without the corresponding name attribute
>>>>>> defining the actual node type. However, x3dom expects a name attribute with
>>>>>> every ProtoInstance statement, even USE ones, to be able to insert the
>>>>>> appropriate node.
>>>>>>
>>>>>> The xml spec  at
>>>>>>
>>>>>>
>>>>>> https://www.web3d.org/documents/specifications/19776-1/V3.3/Part01/concepts.html#ProtoInstanceAndFieldValueStatement
>>>>>>
>>>>>> does not address USE of ProtoInstances but all examples always have a
>>>>>> name attribute.
>>>>>>
>>>>>> Also, in my quite extensive testing of Protos, I did not come across
>>>>>> other examples of ProtoInstance elements without a name attribute.
>>>>>>
>>>>>> To be fair, the name attribute is not strictly necessary for USE
>>>>>> ProtoInstances since the type of the inserted node can be determined from
>>>>>> the referenced DEF node. But having the name attribute makes ProtoInstance
>>>>>> elements more similar to regular nodes. So I think not requiring the name
>>>>>> attribute for USE ProtoInstances should be explicitly allowed in the xml
>>>>>> spec., but still be encouraged.
>>>>>>
>>>>>> I do not think the xml spec. would be otherwise affected by V.4 ?
>>>>>>
>>>>>> Best, Andreas
>>>>>>
>>>>>> --
>>>>>> Andreas Plesch
>>>>>> Waltham, MA 02453
>>>>>> _______________________________________________ x3d-public mailing
>>>>>> list x3d-public at web3d.org
>>>>>> http://web3d.org/mailman/listinfo/x3d-public_web3d.org
>>>>>>
>>>>>
>>>>>
>>>>> --
>>>>> Andreas Plesch
>>>>> Waltham, MA 02453
>>>>>
>>>>
>>>
>>> --
>>> Andreas Plesch
>>> Waltham, MA 02453
>>>
>> _______________________________________________ x3d-public mailing list
>> x3d-public at web3d.org
>> http://web3d.org/mailman/listinfo/x3d-public_web3d.org
>>
>
>
> --
> Andreas Plesch
> Waltham, MA 02453
>
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