[x3d-public] Thoughts for x3d.py str() calls

Mon Oct 16 13:47:02 PDT 2023

The x3d.py makes no effort to correct author errors.  That is up to the author.  Trying to “fix” things further can lead to further problems and a corrupted model.

There are a great many models in X3D Examples with DEF and USE which run properly in unit tests.

There are several diagnostics built in for reporting errors.  Have you tested your erroneous scene to see what you get?  If a further error diagnostic is needed, we can add it to the  X3DPSAIL TODO list.  If you write a python method to do that, we can test it further and possibly integrate it.

*	X3D Python Scene Access Interface Library (X3DPSAIL), TODO
*	https://www.web3d.org/x3d/stylesheets/python/python.html#TODO

If a correct model is getting exported into another form incorrectly, then we can diagnose and fix the conversion.  As ever, use-case examples of such errors are essential to continuing progress.

Thanks for all efforts with X3D Python.

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: GPU Group <gpugroup at gmail.com> 
Sent: Monday, October 16, 2023 9:49 AM
To: John Carlson <yottzumm at gmail.com>
Cc: Brutzman, Donald (Don) (CIV) <brutzman at nps.edu>; Joe D Williams <joedwil at earthlink.net>; Peitso, Loren (CIV) <lepeitso at nps.edu>; X3D Graphics public mailing list <x3d-public at web3d.org>
Subject: Re: Thoughts for x3d.py str() calls

correction first output is 

  <Scene>

    <Group DEF='A'>

      <Transform DEF='C'/>

    </Group>

    <Group DEF='B'>

      <Transform DEF='C'/>

    </Group>

On Mon, Oct 16, 2023 at 10:32 AM GPU Group <gpugroup at gmail.com <mailto:gpugroup at gmail.com> > wrote:

That may relate to the DEF USE issue with X3D.py: 

x x3d.py makes no effort to conjugate DEF and USE and properly order DEF before USE in its export stream

- not a common problem unless a node has 2 fields that take the same node (directly SF or indirectly in MFNode descendent field)

x it's a problem with HAnimHumanoid which has coordinate and skin fields, which typically involve the same Coordinate node

- tinkering can be done in the blender exporter, to do a USE before a DEF,  but with inconvenience and messy code

If a call can be made in x3d.py before exporting a DEF or USE, then that function can be over-ridden to take responsibility for DEF USE conjugation and correct output ordering something like this:

node = getDefOrUse(node, node.DEF, node.USE)

and for the x3d.py default it would just return the same element (or node), and overrides can do something more sophisticated.

more..

DEF USE NON-CONJUGATION IN X3D.PY

test_def.py

x3d = X3D()

scene = Scene()

x3d.Scene = scene

grpa = Group(DEF='A')

grpb = Group(DEF='B')

scene.children.append(grpa)

scene.children.append(grpb)

trans = Transform(DEF='C')

grpb.children.append(trans)

grpa.children.append(trans)

blob = x3d.XML()

fp = open("dump.x3d","w+")

fp.write(blob)

fp.close()

output:

<?xml version="1.0" encoding="UTF-8"?>

<!DOCTYPE X3D PUBLIC "ISO//Web3D//DTD X3D 4.0//EN" "https://www.web3d.org/specifications/x3d-4.0.dtd">

<X3D profile='Full' version='4.0' xmlns:xsd='http://www.w3.org/2001/XMLSchema-instance <https://nam10.safelinks.protection.outlook.com/?url=http%3A%2F%2Fwww.w3.org%2F2001%2FXMLSchema-instance&data=05%7C01%7Cbrutzman%40nps.edu%7C5c09532fc6784acf636108dbce67ceb2%7C6d936231a51740ea9199f7578963378e%7C0%7C0%7C638330717470356414%7CUnknown%7CTWFpbGZsb3d8eyJWIjoiMC4wLjAwMDAiLCJQIjoiV2luMzIiLCJBTiI6Ik1haWwiLCJXVCI6Mn0%3D%7C3000%7C%7C%7C&sdata=yglIKBZsT6BoJS9%2BDnaKptd%2FEdy4pnjHp4KFFEuFFLQ%3D&reserved=0> ' xsd:noNamespaceSchemaLocation='https://www.web3d.org/specifications/x3d-4.0.xsd'>

  <Scene>

    <Group DEF='A'>

      <Transform USE='C'/>

    </Group>

    <Group DEF='B'>

      <Transform DEF='C'/>

    </Group>

  </Scene>

</X3D>

test_def_use.py

from x3d import *

x3d = X3D()

scene = Scene()

x3d.Scene = scene

grpa = Group(DEF='A')

grpb = Group(DEF='B')

scene.children.append(grpa)

scene.children.append(grpb)

trans = Transform(DEF='C')

grpb.children.append(trans)

grpa.children.append(trans)

blob = x3d.XML()

fp = open("dump.x3d","w+")

fp.write(blob)

fp.close()

output:

<?xml version="1.0" encoding="UTF-8"?>

<!DOCTYPE X3D PUBLIC "ISO//Web3D//DTD X3D 4.0//EN" "https://www.web3d.org/specifications/x3d-4.0.dtd">

<X3D profile='Full' version='4.0' xmlns:xsd='http://www.w3.org/2001/XMLSchema-instance <https://nam10.safelinks.protection.outlook.com/?url=http%3A%2F%2Fwww.w3.org%2F2001%2FXMLSchema-instance&data=05%7C01%7Cbrutzman%40nps.edu%7C5c09532fc6784acf636108dbce67ceb2%7C6d936231a51740ea9199f7578963378e%7C0%7C0%7C638330717470512654%7CUnknown%7CTWFpbGZsb3d8eyJWIjoiMC4wLjAwMDAiLCJQIjoiV2luMzIiLCJBTiI6Ik1haWwiLCJXVCI6Mn0%3D%7C3000%7C%7C%7C&sdata=C1CiwnRN22BrRL7097t92ojvanIkKyb8xlQeolJXaGc%3D&reserved=0> ' xsd:noNamespaceSchemaLocation='https://www.web3d.org/specifications/x3d-4.0.xsd'>

  <Scene>

    <Group DEF='A'>

      <Transform USE='C'/>

    </Group>

    <Group DEF='B'>

      <Transform DEF='C'/>

    </Group>

  </Scene>

</X3D>

On Mon, Oct 16, 2023 at 10:09 AM GPU Group <gpugroup at gmail.com <mailto:gpugroup at gmail.com> > wrote:

It seems possible to override functions in python, if there are just a few to override. 

And one suggestion for x3d.py imperfections is to apply fixes at runtime in some initialization function.

- that assumes/requires just a few target functions, not 480 functions that need to be repaired

- so for some fixes it may be helpful to change the upstream x3d.py to call a function that can be easily replaced.

-Doug

Example:

file myclass.py 

class Wonky:

  def __init__(self):

    self.color = "Red"

  def func1(self, color :str) -> bool:

    if color == self.color:

      return True

    return False

file override.py

from myclass import *

mc = Wonky()

print("match with Blue? "+str(mc.func1("Blue")))

def func2(self, color: str) -> bool:

  if self.color != color:

    return True

  return False

Wonky.func1 = func2 # <<<<<<<<<<<< OVERRIDE

print("don't match with Blue? "+str(mc.func1("Blue")))

output:

match with Blue? False

don't match with Blue? True

-Doug

On Mon, Oct 16, 2023 at 9:55 AM John Carlson <yottzumm at gmail.com <mailto:yottzumm at gmail.com> > wrote:

Instead of calling str() to print out a value, call a function that does precision floating point formatting on floats according to a user’s wishes.  If the value is a list, call the function recursively with a list comprehension, otherwise, call str. 

I think this is doable by mere humans.

Thanks,

John

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