[semantics-public] [x3d-public] representing DEF/USE information

GPU Group gpugroup at gmail.com
Thu Nov 7 12:24:55 PST 2019 

IDEA: a stack-based method for default USE
In the past I've used Switch -1 to hide pre-defined nodes for later USE.
Another idea: to have some generic way to change a default via a stack of
some sort:
<Stack name="material" USE='funnyMaterial'>
<Shape>
- no material mentioned, no USE here, gets the default which is
funnyMaterial
</Shape>
<Stack name='material' USE='seriousMaterial'>
<Shape>
- no material mentioned, gets default which is now seriousMaterial
</Shape>
</Stack> - pops serious
<Shape>
- no material mentioned, gets default which is back to funnyMaterial
</Shape>
</Stack> - pops funny
<Shape>
- no material mentioned, gets x3d default material
</Shape>
But I haven't thought about when / what other scenarios that would be
useful for. Just something new related to DEF/USE.
-Doug Sanden

On Thu, Nov 7, 2019 at 6:52 AM Brutzman, Donald (Don) (CIV) <
brutzman at nps.edu> wrote:

> John, you've identified unfinished business in our design pattern for
> RDF/OWL representation of an X3D model. Thank you for close review. We
> never resolved this question.
>
> Right now the relationship is only apparent from the names
> (:MaterialLightBlue and :MaterialLightBlue-USE-1) which are informational
> for people and not a basis for inference.  Am expecting that the provided
> naming pattern for DEF/USE/other nodes is simply syntactic sugar provided
> during by X3dToTurtle.xslt conversion, not something we would require in a
> specification design.
>
> Adding "owl:sameAs :MaterialLightBlue ; # USE" to
> :MaterialLightBlue-USE-1  (as part of X3dToTurtle.xslt conversion) appears
> to be needed.  Or perhaps something else, as considered in our prior emails
> below.
>
> Another omission: not finding the DEF name included in the triples.  That
> is part of the original model and not information that should be lost.
> Perhaps adding "rdfs:label :MaterialLightBlue ; # DEF" to
> :MaterialLightBlue is also needed.  We should look at other uses of RDF/OWL
> and see how they handle representations of ID information.
>
> Next step: what would relevant questions be regarding DEF and USE nodes be
> that would utilize this relationship?  Perhaps hasDEF hasUSE isUSE
> properties, or inferences? These can inform writing some queries and seeing
> if the owl:sameAs relationship works OK.  Those steps are still needed.
>
> Further consideration and experimentation will be helpful, this
> information is pretty central and we want to get it right.
>
>
> Relevant triples from HelloWorld.ttl
> https://www.web3d.org/x3d/content/semantics/examples/HelloWorld.ttl
> =====================================
> :Appearance_2_2_2_1_2 a owl:NamedIndividual, x3do:Appearance ;
>    x3do:hasParent :Shape_2_2_2_1 ;
>    x3do:hasMaterial :MaterialLightBlue ;
>    x3do:hasTexture :ImageCloudlessEarth .
> :MaterialLightBlue a owl:NamedIndividual, x3do:Material ;
>    x3do:hasParent :Appearance_2_2_2_1_2 ;
>    x3do:diffuseColor '0.1 0.5 1' .
>
> :Appearance_2_2_3_1_2 a owl:NamedIndividual, x3do:Appearance ;
>    x3do:hasParent :Shape_2_2_3_1 ;
>    x3do:hasMaterial :MaterialLightBlue-USE-1 .
> :MaterialLightBlue-USE-1 a owl:NamedIndividual, x3do:Material ;
>    x3do:hasParent :Appearance_2_2_3_1_2 .
> =====================================
>
>
> Relevant specification clause:
> https://www.w3.org/TR/owl-ref/#sameAs-def
> =========================================
> 5.2.1 owl:sameAs
>
> The built-in OWL property owl:sameAs links an individual to an individual.
> Such an owl:sameAs statement indicates that two URI references actually
> refer to the same thing: the individuals have the same "identity".
>
> For individuals such as "people" this notion is relatively easy to
> understand. For example, we could state that the following two URI
> references actually refer to the same person:
>
> <rdf:Description rdf:about="#William_Jefferson_Clinton">
>    <owl:sameAs rdf:resource="#BillClinton"/>
> </rdf:Description>
>
> The owl:sameAs statements are often used in defining mappings between
> ontologies. It is unrealistic to assume everybody will use the same name to
> refer to individuals. That would require some grand design, which is
> contrary to the spirit of the web.
>
> In OWL Full, where a class can be treated as instances of (meta)classes,
> we can use the owl:sameAs construct to define class equality, thus
> indicating that two concepts have the same intensional meaning. An example:
>
> <owl:Class rdf:ID="FootballTeam">
>    <owl:sameAs rdf:resource="http://sports.org/US#SoccerTeam"/>
> </owl:Class>
>
> One could imagine this axiom to be part of a European sports ontology. The
> two classes are treated here as individuals, in this case as instances of
> the class owl:Class. This allows us to state that the class FootballTeam in
> some European sports ontology denotes the same concept as the class
> SoccerTeam in some American sports ontology. Note the difference with the
> statement:
>
> <footballTeam owl:equivalentClass us:soccerTeam />
>
> which states that the two classes have the same class extension, but are
> not (necessarily) the same concepts.
>
> NOTE: For details of comparison of URI references, see the section on RDF
> URI references in the RDF Concepts document [RDF Concepts].
> =========================================
>
>
>
> On 11/2/2019 7:44 PM, John Carlson wrote:
> > Aha, ignore previous email, I found this.  It would seem if we had
> multiple sameAs it would be confusing semantically?  Not really sure.
> >
> > 5. *Improved DEF/USE representation possibilities*
> >
> > /Next question/. Wondering: when we define nodes that have a DEF or USE,
> should we also define owl:sameAs for the regular naming convention of
> individuals that indicates graph position in the original scene graph?
> >
> > For example, current form
> >
> > :ViewUpClose a owl:NamedIndividual, x3do:Viewpoint ; # current
> >
> >     x3do:hasParent :Group_2_2 ;
> >
> >     x3do:centerOfRotation "0 -1 0" ;
> >
> >     x3do:description "Hello world!" ;
> >
> >     x3do:position "0 -1 7" .
> >
> > would become
> >
> > :Viewpoint_2_2_1 a owl:NamedIndividual, x3do:Viewpoint ; # proposed
> >
> >     owl:sameAs :ViewUpClose ; # DEF
> >
> >     x3do:hasParent :Group_2_2 ;
> >
> >     x3do:centerOfRotation "0 -1 0" ;
> >
> >     x3do:description "Hello world!" ;
> >
> >     x3do:position "0 -1 7" .
> >
> > Similarly considering USE nodes, we might further elaborate these
> relationships by describing equivalence of numbered-label with USE name and
> with original DEF node...  Current form:
> >
> > :MaterialLightBlue a owl:NamedIndividual, x3do:Material ; # current
> >
> >     x3do:hasParent :Appearance_2_2_2_1_2 ;
> >
> >     x3do:diffuseColor "0.1 0.5 1" .
> >
> > would become:
> >
> > :Material_2_2_3_1_2_1 a owl:NamedIndividual, x3do:Material ; # proposed
> >
> >     owl:sameAs :MaterialLightBlue ; # USE
> >
> >     owl:sameAs :MaterialLightBlue-USE-1 ; # USE
> >
> >     x3do:hasParent :Appearance_2_2_3_1_2 .
> >
> > However, if we are going to call them owl:sameAs, they might not be
> sufficiently distinguished from the original DEF.  Perhaps subclassOf is a
> better relationship?
> >
> > Please consider.  I will apply next pattern to all examples for further
> testing.
>
>
> 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
> http://faculty.nps.edu/brutzman
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