[x3d-public] X3DGroupingNode interface has no method setIS in X3DJSAIL, FYI

Sat Jan 5 18:29:45 PST 2019

On 1/4/2019 10:49 PM, John Carlson wrote:
> Thank you all for considering this code.  Note that one works, and here is the failure for the other. It appears when you use concrete classes and not interfaces, it works.  The interface does not have the method.   We will have to figure out some kind of casting scheme, I think.
> 
> John

[Summary: interesting python examples, progress possible, analysis follows.]

Original scene and alternatives at available at

[1] http://www.web3d.org/x3d/content/examples/Basic/ChemicalMarkupLanguage/GlycerolDiacetate.x3d

[2] http://www.web3d.org/x3d/content/examples/Basic/ChemicalMarkupLanguage/GlycerolDiacetateIndex.html

[3] http://www.web3d.org/x3d/content/examples/Basic/javadoc/Basic/ChemicalMarkupLanguage/GlycerolDiacetate.html

[4] http://www.web3d.org/x3d/content/examples/Basic/ChemicalMarkupLanguage/GlycerolDiacetate.java

[5] http://www.web3d.org/x3d/tooltips/X3dTooltips.html#IS

[6] http://www.web3d.org/specifications/java/javadoc/org/web3d/x3d/jsail/Core/ISObject.html

[7] http://www.web3d.org/specifications/java/javadoc/org/web3d/x3d/jsail/Core/connectObject.html

IS appears within a ProtoDeclare, saying that a node's field IS provided by an ancestor ProtoDeclare field declaration.

======================================================================
XML scene excerpt matching your example below:

<ProtoDeclare name='Hydrogen'>
   <ProtoInterface>
     <field accessType='inputOutput' name='position' type='SFVec3f' value='0 0 0'/>
     <field accessType='inputOutput' name='Mat' type='SFFloat' value='.6'/>
   </ProtoInterface>
   <ProtoBody>
     <Group>
       <Transform DEF='atoH'>
         <IS>
           <connect nodeField='translation' protoField='position'/>
         </IS>
         <Shape>
           <Appearance>
             <Material DEF='atoH_mat' ambientIntensity='.0933' diffuseColor='.38 .38 .42' shininess='0.5' specularColor='.53 .53 .53'>
               <IS>
                 <connect nodeField='transparency' protoField='Mat'/>
               </IS>
             </Material>
           </Appearance>
           <Sphere radius='.32'/>
         </Shape>
         <Shape>
           <Appearance>
             <Material diffuseColor='0.9 0.9 0.9'/>
           </Appearance>
           <Text string='"H"'>
             <FontStyle size='.4'/>
           </Text>
         </Shape>
       </Transform>
     </Group>
   </ProtoBody>
</ProtoDeclare>
======================================================================
Java scene excerpt matching your example below:

.addChild(new ProtoDeclareObject("Hydrogen").setName("Hydrogen")
   .setProtoInterface(new ProtoInterfaceObject()
     .addField(new fieldObject().setName("position").setType(fieldObject.TYPE_SFVEC3F).setAccessType(fieldObject.ACCESSTYPE_INPUTOUTPUT).setValue(new SFVec3fObject(0.0f,0.0f,0.0f)))
     .addField(new fieldObject().setName("Mat").setType(fieldObject.TYPE_SFFLOAT).setAccessType(fieldObject.ACCESSTYPE_INPUTOUTPUT).setValue(.6f)))
   .setProtoBody(new ProtoBodyObject()
     .addChild(new GroupObject()
       .addChild(new TransformObject("atoH")
         .setIS(new ISObject()
           .addConnect(new connectObject().setNodeField("translation").setProtoField("position")))
         .addChild(new ShapeObject()
           .setAppearance(new AppearanceObject()
             .setMaterial(new MaterialObject("atoH_mat").setAmbientIntensity(.0933f).setDiffuseColor(.38f,.38f,.42f).setShininess(0.5f).setSpecularColor(.53f,.53f,.53f)
               .setIS(new ISObject()
                 .addConnect(new connectObject().setNodeField("transparency").setProtoField("Mat")))))
           .setGeometry(new SphereObject().setRadius(.32f)))
         .addChild(new ShapeObject()
           .setAppearance(new AppearanceObject()
             .setMaterial(new MaterialObject().setDiffuseColor(0.9f,0.9f,0.9f)))
           .setGeometry(new TextObject().setString(new MFStringObject("\"H\""))
             .setFontStyle(new FontStyleObject().setSize(.4f))))))))
======================================================================

As you point out, IS gets defined by X3DJSAIL on a per-node basis.  That is because each node might include a single IS statement (which in turn contains zero or more "connect" statements).
- For example, TransformObject setIS()
	http://www.web3d.org/specifications/java/javadoc/org/web3d/x3d/jsail/Grouping/TransformObject.html#setIS-org.web3d.x3d.jsail.Core.ISObject-
- For example, MaterialObject setIS()
	http://www.web3d.org/specifications/java/javadoc/org/web3d/x3d/jsail/Shape/MaterialObject.html#setIS-org.web3d.x3d.jsail.Core.ISObject-

First reaction: looks like we might possibly migrate the setIS() getIS() methods upwards to org.web3d.x3d.sai.Core.X3DNode class.  That way it would appear wherever set/get DEF and USE and CssClass accessor methods appear.  However this is a spec-defined abstract X3D SAI class, not an X3DJSAIL class...

[8] http://www.web3d.org/specifications/java/javadoc/org/web3d/x3d/sai/Core/X3DNode.html

[9] http://www.web3d.org/documents/specifications/19777-2/V3.3/Part2/abstracts.html#X3DNode

Of direct interest is that the DEF/USE/class methods are not defined there in that abstract SAI class... and can likely be moved to an X3DJSAIL instead.

Aha, am remembering that DEF/USE access was originally controversial in all of the all of the language bindings (is it a string field? is it pointer? is it an object reference? is it programming-language specific?  is it implementation specific?) and was left out of abstract SAI.  Indeed checking back in abstract SAI specification, am not finding any general requirement to set/get DEF or USE values.  This seems like a hole in the abstract SAI, frankly.  Specification itself:

[10] X3D Scene access interface (SAI)
	http://www.web3d.org/documents/specifications/19775-2/V3.3/Part02/X3D_SAI.html

hmmm another TODO: statements such as IMPORTObject ROUTEObject ExternProtoDeclareObject ProtoDeclareObject etc. should not be in list of implementing classes there...  looks like a twist in the X3DJSAIL class hierarchy, these get @Deprecated where they implemented (since you cannot DEF or USE a ROUTE statement, for example).

So, moving the DEF/USE/CssClass methods out of org.web3d.x3d.sai.Core.X3DNode does not violate abstract SAI, or Java SAI.  Good, that gives us an opening for improvement here.  Probably these methods should all go to org.web3d.x3d.jsail.X3DConcreteNode interface instead... hey wait a minute, there are some abstract methods already there for DEF/USE.

[10] http://www.web3d.org/specifications/java/javadoc/org/web3d/x3d/jsail/X3DConcreteNode.html

I will work on refactoring the x3djsail/sai class hierarchy accessor get/set methods for DEF USE CssClass and IS more consistently.  The .x3d and .java scene source patterns above won't change, this is all internal.

Tricky business indeed, please stand by for refactoring of X3DJSAIL class/interface hierarchy.

So don't worry about casting at this stage.  Thanks for triggering this analysis.

p.s. looks like you have method pipelining going in the second version!  8)

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