[x3d-public] Problem in x3dviewscene: ROUTE placement

Sun Jun 11 14:36:40 PDT 2023

John, here is a JSON autogenerated example (using stylesheet we developed together) matching the other forms provided in response to Michalis.  Many more available, likely does not need to be on your TODO list.

*	https://www.web3d.org/x3d/content/examples/Vrml2Sourcebook/Chapter08AnimatingPositionOrientationScale/Figure08_3PositionInterpolator.json

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: John Carlson <yottzumm at gmail.com> 
Sent: Saturday, June 10, 2023 12:30 PM
To: Brutzman, Donald (Don) (CIV) <brutzman at nps.edu>
Cc: Michalis Kamburelis <michalis.kambi at gmail.com>; X3D Graphics public mailing list <x3d-public at web3d.org>
Subject: Re: [x3d-public] Problem in x3dviewscene: ROUTE placement

I believe this example is current.  It shows a mixed-node result. 

The third option was taken, which should preserve structure across encodings.  I will also run this example through my Java and JavaScript JSON validators.

John

On Sat, Jun 10, 2023 at 2:14 PM John Carlson <yottzumm at gmail.com <mailto:yottzumm at gmail.com> > wrote:

The third option was chosen, with only advantages, possibly.

Probably it would be easiest to create an example.  I will put that on my todo list.

John

On Sat, Jun 10, 2023 at 2:10 PM John Carlson <yottzumm at gmail.com <mailto:yottzumm at gmail.com> > wrote:

Here: “Disadvantages: ordering of ROUTE statements is lost, relative to other children nodes. ROUTEs are placed at the end, only a partial order is retained.”

From:

https://www.web3d.org/x3d/stylesheets/X3dToJson.html

John

On Sat, Jun 10, 2023 at 2:03 PM John Carlson <yottzumm at gmail.com <mailto:yottzumm at gmail.com> > wrote:

I’m further remembering perhaps that these many routes were placed into a JSON array of routes?

It’s been a very long time, I would have to recheck.

Water under the bridge?

On Sat, Jun 10, 2023 at 1:58 PM John Carlson <yottzumm at gmail.com <mailto:yottzumm at gmail.com> > wrote:

My impression was that they were being moved out (from a nested context) or down the scenegraph, collecting many routes together.

I didn’t write X3dToJson.xslt.  It’s not my expertise, but i may be able to find some examples with roundtripping.

It would be easy to test by sprinkling many routes at same level in XML, then convert to JSON to see if they are collected.  I hope this helps.

HAnim is higher priority.

John

On Sat, Jun 10, 2023 at 1:45 PM Brutzman, Donald (Don) (CIV) <brutzman at nps.edu <mailto:brutzman at nps.edu> > wrote:

Good question, not sure where they are getting moved.  Examples always welcome.  When JSON Schema is finally approved and implemented, we’ll be able to formalize that.

*	X3D Resources, Examples: Scene Archives for X3D
*	https://www.web3d.org/x3d/content/examples/X3dResources.html#Examples

Expectation is that ordering of nodes and ROUTE statements will be consistent for ClassicVRML, XML, JSON, Java, Python, etc., allowing symmetric conversion between representations.  Hence the careful scrutiny as we go.  Thanks for tracking this John.

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: John Carlson <yottzumm at gmail.com <mailto:yottzumm at gmail.com> > 
Sent: Saturday, June 10, 2023 11:28 AM
To: Brutzman, Donald (Don) (CIV) <brutzman at nps.edu <mailto:brutzman at nps.edu> >
Cc: Michalis Kamburelis <michalis.kambi at gmail.com <mailto:michalis.kambi at gmail.com> >; X3D Graphics public mailing list <x3d-public at web3d.org <mailto:x3d-public at web3d.org> >
Subject: Re: [x3d-public] Problem in x3dviewscene: ROUTE placement

Don, does this make it so we don’t have to move routes around in the JSON encoding?

I was not clear why they needed to be moved.

Thanks,

John

On Sat, Jun 10, 2023 at 1:05 PM Brutzman, Donald (Don) (CIV) <brutzman at nps.edu <mailto:brutzman at nps.edu> > wrote:

Well, closer, but not quite there yet.  Here is some more “language lawyering.”  8)

BLUF: it is important and allowed for ROUTE statements (and prototype statements) to appear in MFNode lists, side by side with other nodes.

Not exactly sure what you mean by MFList.  Presumably you mean MFNode, which is one of the approved concrete or abstract types in

*	X3D 4.0 Part 1: Architecture and base components, clause 5 Field type reference
*	https://www.web3d.org/specifications/X3Dv4Draft/ISO-IEC19775-1v4-IS.proof/Part01/fieldTypes.html

I believe that the rules are telling us that the ROUTE statement can appear where other nodes can appear.  Typically that is within an MFNode list.

*	X3D 4.0 Part 1: Architecture and base components, clause 5 Field type reference, 5.3 Field types, 5.3.12 SFNode and MFNode
*	https://www.web3d.org/specifications/X3Dv4Draft/ISO-IEC19775-1v4-IS.proof/Part01/fieldTypes.html#SFNodeAndMFNode
*	The SFNode field specifies an X3D node. The MFNode field specifies zero or more nodes.
*	The default value of an uninitialized SFNode field is NULL. The default value of an MFNode field is the empty list.

The third bullet above likely needs to be modified to say

*	The SFNode field specifies an X3D node. The MFNode field specifies zero or more nodes, also allowing ROUTE or prototype statements.

Also relevant, with another suggested addition, again providing clarity and consistency with 4.4.8.2 Routes and 4.4.4 Prototype semantics:

*	5.2.2 X3DArrayField
*	X3DArrayField is the abstract field type from which all field types that can contain multiple values are derived. All fields derived from X3DArrayField have names beginning with MF (multiple-valued field). MF fields may zero or more values, each of which shall be of the type indicated by the corresponding SF field type. It is illegal for any MF field to mix values of different SF field types.  An MFNode field can also include ROUTE and prototype statements.
*	5.2.3 X3DField
*	X3DField is the abstract field type from which all single values field types are derived. All fields directly derived from X3DField have names beginning with SF (single-valued field). SF fields may only contain a single value of the type indicated by the name of the field type.

Corresponding ClassicVRML grammar productions:

*	X3D 3.3 encodings, Part 2: Classic VRML encoding, Annex A (normative) Grammar, A.2 General
*	https://www.web3d.org/documents/specifications/19776-2/V3.3/Part02/grammar.html#General

statements ::=

statement |

statement statements |

empty ;

statement ::=

nodeStatement |
importStatement |
exportStatement |

protoStatement |

routeStatement ;

nodeStatement ::=

node |

DEF nodeNameId node |

USE nodeNameId ;

IMPORT and EXPORT statements only appear in special locations related to Inline node usage, and don’t seem to need special mention in the prose above.

We certainly have many hundreds of validated examples that include ROUTE statements along with other children nodes, as part of MFNode lists.  Large parts of our existing infrastructure support this construct, in accordance with X3D Architecture.

Bottom line: it is important and allowed for ROUTE statements (and prototype statements) to appear in MFNode lists, side by side with other nodes.

If the two highlighted sentences above seem like useful additions, I’ll create a Mantis issue and we can inquire if ISO editors will accept such a change at this very late date.

Again thanks for careful scrutiny.  Looking forward to regaining full consensus on this important design issue which is critical to consistent X3D model interoperability.

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

-----Original Message-----
From: Michalis Kamburelis <michalis.kambi at gmail.com <mailto:michalis.kambi at gmail.com> > 
Sent: Friday, June 9, 2023 4:46 PM
To: Brutzman, Donald (Don) (CIV) <brutzman at nps.edu <mailto:brutzman at nps.edu> >
Cc: Joseph D Williams <joedwil at earthlink.net <mailto:joedwil at earthlink.net> >; X3D Graphics public mailing list <x3d-public at web3d.org <mailto:x3d-public at web3d.org> >; puk at igraphics.com <mailto:puk at igraphics.com> 
Subject: Re: [x3d-public] Problem in x3dviewscene: ROUTE placement

I do not see any need to change the X3D spec here. For once, it is all correct in X3D spec  :) And "Architecture and base components" is consistent with what "Classic VRML encoding" is saying, and both chapters of "Classic VRML encoding" ("4 Concepts" and "Annex A

(normative) Grammar") are consistent.

Joe's model should just be fixed, from what I can tell -- you have to move ROUTE outside of the [ ... ]. It makes sense that MFList [ ... ] should contain only nodes.

>From what I can tell,

 <https://www.web3d.org/documents/specifications/19776-2/V3.3/Part02/grammar.html> https://www.web3d.org/documents/specifications/19776-2/V3.3/Part02/grammar.html

clearly says that ROUTE cannot be part of MFList [ ... ] , and that's OK. You have to place ROUTE within some node (or at top-level).

Within MFList [ ... ] you can only have nodes (or USE of nodes). You cannot place ROUTE, EXPORT, IMPORT, PROTO... within MFList [ ... ] and that's OK, that's simple. Let's not break it :)

Regards,

Michalis

sob., 10 cze 2023 o 01:30 Brutzman, Donald (Don) (CIV) < <mailto:brutzman at nps.edu> brutzman at nps.edu> napisał(a):

> 

> Thanks for precise response Michalis, very helpful.

> 

> The intent for ROUTE is that it might appear within other nodes.  The phrasing in X3D4 Architecture is quite explicit about this:

> 

> X3D 4.0 Part 1: Architecture and base components, clause 4 Concepts, 

> 4.4.8.2 Routes 

>  <https://www.web3d.org/specifications/X3Dv4Draft/ISO-IEC19775-1v4-IS.pr> https://www.web3d.org/specifications/X3Dv4Draft/ISO-IEC19775-1v4-IS.pr

> oof/Part01/concepts.html#Routes Routes allows an author to 

> declaratively connect the output events of a node to input events of other nodes, providing a way to implement complex behaviors without imperative programming. When a routed output event is fired, the corresponding destination input event receives notification and can process a response to that change. This processing can change the state of the node, generate additional events, or change the structure of the scene graph. Routes may be created declaratively in an X3D file or programmatically via an SAI call.

> Routes are not nodes. The ROUTE statement is a construct for establishing event paths between specified fields of nodes. ROUTE statements may either appear at the top level of an X3D file or inside a node wherever fields may appear. A ROUTE statement shall only appear after the definition of the source and destination nodes. Placing a ROUTE statement within a node does not associate it with that node in any way. A ROUTE statement does follow the name scoping rules as described in 4.4.7 Run-time name scope.

> 

> We expect that the prose and grammar in 19776-2/V3.3 Part 2: Classic VRML encoding to be reviewed and refined to match, when we get back to that document and upgrade it to X3D 4.0.  I think that the current ClassicVRML spec indeed defers to the Architecture specification:

> 

> X3D 3.3 Part 2: Classic VRML encoding, clause 4 Concepts, 4.3.2 

> Statements, 4.3.2.1 Organization of statements “Any number of ROUTE statements as specified in 4.4.8.2 Routes of ISO/IEC 19775-1.”

> 

> So changes (corresponding to your accurate note) may need to be made to

> 

> X3D 3.3 Part 2: Classic VRML encoding, Annex A (normative), Grammar 

>  <https://www.web3d.org/documents/specifications/19776-2/V3.3/Part02/gra> https://www.web3d.org/documents/specifications/19776-2/V3.3/Part02/grammar.html

> 

> 

> 

> Wikipedia: Extended Backus–Naur form (EBNF)

> https://en.wikipedia.org/wiki/Extended_Backus-Naur_form <https://nam10.safelinks.protection.outlook.com/?url=https%3A%2F%2Fen.wikipedia.org%2Fwiki%2FExtended_Backus-Naur_form&data=05%7C01%7Cbrutzman%40nps.edu%7C00493792347e4f819db008db69e92034%7C6d936231a51740ea9199f7578963378e%7C0%7C0%7C638220222248610611%7CUnknown%7CTWFpbGZsb3d8eyJWIjoiMC4wLjAwMDAiLCJQIjoiV2luMzIiLCJBTiI6Ik1haWwiLCJXVCI6Mn0%3D%7C3000%7C%7C%7C&sdata=DcxsWZcLGeEt%2Fgglrmzr9yqc5s1dDJ9dXe4tpGXAc%2Bs%3D&reserved=0>  

> 

> 

> which includes the following EBNF production rules:

> 

> 

> 

> node ::=

> 

> nodeTypeId { nodeBody } |

> 

> Script { scriptBody } |

> 

> ComposedShader {composedShaderBody} |

> PackagedShader {packagedShaderBody} |

> ShaderProgram {shaderProgramBody} ;

> 

> nodeBody ::=

> 

> nodeBodyElement |

> 

> nodeBodyElement nodeBody |

> 

> empty ;

> 

> nodeBodyElement ::=

> 

> initializeOnlyId fieldValue |

> inputOutputId fieldValue |

> 

> initializeOnlyId IS initializeOnlyId |

> 

> inputOnlyId IS inputOnlyId |

> 

> outputOnlyId IS outputOnlyId |

> 

> inputOutputId IS inputOutputId |

> 

> routeStatement |

> 

> protoStatement ;

> 

> and

> 

> routeStatement ::=

> 

> ROUTE nodeNameId . outputOnlyId TO nodeNameId . inputOnlyId ;

> 

> 

> 

> which, at first glance, looks OK to me from perspective of Joe’s 

> example (and many other examples)…

> 

> 

> 

> Do you have modifications to suggest for the grammar?

> 

> 

> 

> p.s. I tried to add a Mantis issue for long-term tracking but had trouble getting form to respond properly, will try again another time.

> 

> Ensure ClassicVRML grammar matches X3D 4.0 Architecture Concepts and rules.

> In particular, closely examine placement of ROUTE statements.

> 

> 

> 

> all the best, Don

> 

> --

> 

> Don Brutzman  Naval Postgraduate School, Code USW/Br         <mailto:brutzman at nps.edu> 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> https://faculty.nps.edu/brutzman

> 

> 

> 

> -----Original Message-----

> From: Michalis Kamburelis < <mailto:michalis.kambi at gmail.com> michalis.kambi at gmail.com>

> Sent: Friday, June 9, 2023 2:11 PM

> To: Joseph D Williams < <mailto:joedwil at earthlink.net> joedwil at earthlink.net>

> Cc: Brutzman, Donald (Don) (CIV) < <mailto:brutzman at nps.edu> brutzman at nps.edu>; X3D Graphics 

> public mailing list < <mailto:x3d-public at web3d.org> x3d-public at web3d.org>

> Subject: Re: [x3d-public] Problem in x3dviewscene: ROUTE placement

> 

> 

> 

> 

> 

> The ROUTE cannot go anywhere in the file, in particular you cannot place it inside an MFNode.

> 

> 

> 

>  <https://www.web3d.org/documents/specifications/19776-2/V3.3/Part02/con> https://www.web3d.org/documents/specifications/19776-2/V3.3/Part02/con

> cepts.html

> 

> : ROUTE is allowed at top-level and in node's body,

> 

> 

> 

> """

> 

> A node's body consists of any number of field statements, IS statements, ROUTE statements, PROTO statements or EXTERNPROTO statements, in any order.

> 

> """

> 

> 

> 

> The grammar confirms this precisely:

> 

> 

> 

>  <https://www.web3d.org/documents/specifications/19776-2/V3.3/Part02/gra> https://www.web3d.org/documents/specifications/19776-2/V3.3/Part02/gra

> mmar.html

> 

> :

> 

> 

> 

> - mfnodeValue is a sequence of nodeStatement

> 

> - nodeStatement is only "USE ...", "DEF Xxx Node { }" or "Node { }"

> 

> - only the more general "statement" allows ROUTE (and IMPORT, EXPORT, PROTO...). The "statement" is inside a node (but not in MFNode list).

> 

> 

> 

> Regards,

> 

> Michalis

> 

> 

> 

> 

> 

> 

> 

> 

> 

> pt., 9 cze 2023 o 22:37 Joseph D Williams < <mailto:joedwil at earthlink.net> joedwil at earthlink.net> napisał(a):

> 

> >

> 

> > Hi All,

> 

> >

> 

> > My problem with view3dscene 4.3.0 is that it quits reading upon this sequence:

> 

> >

> 

> >

> 

> >

> 

> > DEF StandAnimation Group {

> 

> >

> 

> > children [

> 

> >

> 

> > DEF StandTimer TimeSensor { … }

> 

> >

> 

> > DEF Stand_r_metatarsalPitch OrientationInterpolator {

> 

> >

> 

> >   key [ … ]

> 

> >

> 

> >   keyValue [ ... ]} ...

> 

> >

> 

> > ROUTE StandTimer.fraction_changed TO

> 

> > Stand_r_ankleRotInterp.set_fraction

> 

> >

> 

> > ]}

> 

> >

> 

> > …

> 

> >

> 

> >

> 

> >

> 

> > When it finds a ROUTE as child of Group. The error is:

> 

> >

> 

> >

> 

> >

> 

> > VRML/X3D: Error when reading, will skip the rest of X3D file:

> 

> >

> 

> > Error at line 661 column 6:

> 

> >

> 

> > Expected node type or DEF or USE, got keyword "ROUTE"

> 

> >

> 

> > Making this construction required.

> 

> >

> 

> >

> 

> >

> 

> > DEF StandAnimation Group {

> 

> >

> 

> > children [

> 

> >

> 

> > DEF StandTimer TimeSensor { … }

> 

> >

> 

> > DEF Stand_r_metatarsalPitch OrientationInterpolator {

> 

> >

> 

> >   key [ … ]

> 

> >

> 

> >   keyValue [ ... ]} ...

> 

> >

> 

> > ]}

> 

> >

> 

> > ROUTE StandTimer.fraction_changed TO

> 

> > Stand_r_ankleRotInterp.set_fraction

> 

> >

> 

> > …

> 

> >

> 

> >

> 

> >

> 

> > Moving the Route outside the Group.

> 

> >

> 

> > I think we went through the gram in detail here and found that placing the statement in this MF should be OK.

> 

> >

> 

> >

> 

> >

> 

> > Thanks,

> 

> >

> 

> > Joe

> 

> >

> 

> >

> 

> >

> 

> > Clipped for mercy

> 

> >

> 

> >

> 

> >

> 

> > From: x3d-public < <mailto:x3d-public-bounces at web3d.org> x3d-public-bounces at web3d.org> On Behalf Of Joseph 

> > D

> 

> > Williams

> 

> > Sent: Friday, June 9, 2023 10:29 AM

> 

> > To: X3D Graphics public mailing list < <mailto:x3d-public at web3d.org> x3d-public at web3d.org>

> 

> > Subject: [x3d-public] Problem in x3dviewscene: ROUTE placement

> 

> >

> 

> >

> 

> >

> 

> > Error in viewX3dScene processing

> 

> >

> 

> >

> 

> >

> 

> > VRML/X3D: Error when reading, will skip the rest of X3D file: Error at line 661 column 6: Expected node type or DEF or USE, got keyword "ROUTE"

> 

> >

> 

> >

> 

> >

> 

> > I was hoping we could fix this player problem since we determined that a ROUTE statement can go anywhere in the file.

> 

> >

> 

> > Thanks,

> 

> >

> 

> > Joe

> 

> >

> 

> >

> 

> >

> 

> >

> 

> >

> 

> >

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