[x3d-public] ProtoBody completeness in nested Protos

[GPU Group]

"..assuming that the outer scene
Execution Context should apply also to the Proto Execution Context. I
do not think this is the case. Or is it ?"
freewrl: contexts inherit defined protos from parent contexts.
(as you go down the stack of contexts with nested protos, deeper proto
contexts inherit the defined protos of the parent context)

On Mon, Apr 25, 2022 at 9:21 AM Andreas Plesch <andreasplesch at gmail.com>
wrote:

> On Mon, Apr 25, 2022 at 12:43 AM Brutzman, Donald (Don) (CIV)
> <brutzman at nps.edu> wrote:
>
> > Actually please look a little more closely at that (admittedly tricky)
> > example.
>
> Thanks, looking closely is when I noticed that the CircleFishLod
> ProtoBody is not completely defined within itself.
>
> > * CircleFish is an ExternProto, separately defined in another file
> > * CircleFishLod is a ProtoDeclare defined in that first file,
> > CircleFishLodPrototype.x3d
> > * CircleFishLod ProtoBody contains two ProtoInstance copies of CircleFish
>
> Yes, but the CircleFishLod ProtoBody does not contain the CircleFish
> ExternProtoDeclare (referencing the CircleFish ExternProto) which the
> two copies of CircleFish use. So the ProtoBody is incomplete.
>
> > * CircleFishLod ProtoDeclare is then followed by a CircleFishLod
> > ProtoInstance (again  in CircleFishLodPrototype.x3d)
> > So I would expect an X3D Browser to
> >
> > a. load ExternProtoDeclare      CircleFish
>
> At this point the ProtoDeclaration is only registered under its name,
> in the outer scene Execution Context. The protos array of the
> Execution Context stores it :
>
> https://www.web3d.org/documents/specifications/19777-1/V3.3/Part1/functions.html#t-ExecutionContextProperties
> .
>
> > b. build ProtoDeclare                CircleFishLod
> > c. create inner ProtoInstance  CircleFish for use
>
> This ProtoInstance creation will look for the CircleFish
> ProtoDeclaration, in the CircleFishLod Execution Context which is
> separate from the scene execution context/name scope. But it is only
> registered in the outer scene Context.
>
> > d. create outer ProtoInstance CircleFishLod
>
> In the example (not necessarily in the Proto x3d).
>
> > Order of steps might vary a bit, but those are the dependencies.  Good
> luck
> > sir.
>
> Well, thanks for listing the specific steps which helped illuminate
> that there is a deeper issue with assuming that the outer scene
> Execution Context should apply also to the Proto Execution Context. I
> do not think this is the case. Or is it ?
>
> This scrutiny confirms to me that there is likely an oversight in the
> CircleFishLod example. The example only happens to work in some
> browsers which are more accepting of mixing Execution Contexts. The
> example can be easily fixed by moving the ExternProtoDeclare inside
> the ProtoBody, similar to other examples of nested Prototypes. In fact
> all other examples of nested prototypes I could find do this.
>
> Happy to be convinced otherwise,
>
> Andreas
>
> > 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: x3d-public <x3d-public-bounces at web3d.org> On Behalf Of Andreas
> Plesch
> > Sent: Sunday, April 24, 2022 9:08 PM
> > To: X3D Graphics public mailing list <x3d-public at web3d.org>
> > Subject: [x3d-public] ProtoBody completeness in nested Protos
> >
> > ProtoDeclarations may use ProtoInstances of other Protos inside their
> > ProtoBody definitions.
> >
> > For example, the CircleFishLod proto here:
> >
> >
> https://nam10.safelinks.protection.outlook.com/?url=https%3A%2F%2Fx3dgraphic
> > s.com
> %2Fexamples%2FX3dForWebAuthors%2FKelpForestExhibit%2FCircleFishLodProto
> > typeIndex.html&data=05%7C01%7Cbrutzman%40nps.edu
> %7C0b4a867ba9874e371f9b0
> >
> 8da267152fa%7C6d936231a51740ea9199f7578963378e%7C0%7C0%7C637864565880708349%
> >
> 7CUnknown%7CTWFpbGZsb3d8eyJWIjoiMC4wLjAwMDAiLCJQIjoiV2luMzIiLCJBTiI6Ik1haWwi
> >
> LCJXVCI6Mn0%3D%7C3000%7C%7C%7C&sdata=upr4eckI8axT7MO5fAUvAWfyBzUJfhTwqcp
> > BuH7tZjc%3D&reserved=0
> >
> > uses ProtoInstances of the CircleFish proto.
> >
> > A more extreme case of nesting is:
> >
> >
> https://www.web3d.org/x3d/content/examples/ConformanceNist/Miscellaneous/PRO
> > TO/fivedeepnestingIndex.html
> >
> > where Proto1 uses ProtoInstance of Proto2 inside its ProtoBody. Proto2
> > itself uses a ProtoInstance of Proto3 inside its ProtoBody. And so on to
> > five levels deep.
> >
> > The second example with the deep nesting currently works with x3dom but
> the
> > seemingly simpler CircleFishLod proto does not.
> >
> > The reason is that x3dom expects the complete definition of a proto to be
> > contained in its ProtoBody. However, The CircleFishLod proto only
> contains
> > the CircleFish ProtoInstances in the body but not the associated
> CircleFish
> > ProtoDeclaration which for some reason occurs outside the CircleFishLod
> > ProtoBody (and outside the CircleFishLod ProtoDeclaration).
> >
> > Expecting the ProtoBody to be complete and self-contained seems rather
> > natural. Is x3dom too strict in this regard, or is there an oversight in
> the
> > example ? There is not much guidance in the spec., if any.
> >
> > Thanks, 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
>
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>
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