[x3d-public] How’s John? What I’m working on next

[John Carlson]

The advantage of SDNA is that it’s backwards and forwards compatible
between different versions of Blender, according to docs.  That can’t be
said of the python API.   I don’t know if the blender-file package is
backwards and forwards compatible or not.

The main reason to go with SDNA is that there’s a level of introspection
not available to the python API, afaik.   One can’t view the inside of C++
classes to pull out values with the python API, afaik.   I don’t know if
the python API is introspective or not…i don’t know python that well either.

I fully expect that what I write will be mostly generated/meta.  At least
that’s the plan.   If you can show an approach that can be generated using
the python API, I’m all ears.   I may even split the output into 400+ files.

I’m not really looking at doing a hand-coded solution at this time.  I’m
looking at doing a minimal amount of coding for the largest effect.  I am
not capable of reading an extensive API doc.   Something like JavaDoc would
be ideal.

I am not specifically targeting X3D (the standards) at this time.  What I’m
trying to do is figure out more of a declarative transformer, similar to
XSLT for SDNA.   I may attempt at something like DFDL, ANTLR, Rose
compiler, or  LLVM IR.   I think we’re all wanting an IR for animated
graphics, but there are different goals and constraints for different
software, so we keep falling back to partial solutions.

My previously stated goal was UTF-8.  I may make binary mesh and image
files.

John

On Wed, Jul 14, 2021 at 2:44 AM Michalis Kamburelis <
michalis.kambi at gmail.com> wrote:

> It was last updated in 2017
> https://developer.blender.org/source/blender-file/ . There's only a
> single developer. TBH this approach is really not the way to export X3D
> (or anything else) from Blender, as it is very non-standard. This is
> not the way to go, IMO.
>
> If you want to improve Blender -> X3D exporter, then it's really
> better to follow the standard approach, approved by Blender devs for
> all exporters, and just use the Blender Python API inside Blender --
> https://docs.blender.org/api/current/index.html , following my doc
>
> https://docs.google.com/document/d/1ad5XsU43gQGxqC7ehSBr21mdX2dQjKZCSXUQtvRwTHw/edit?usp=sharing
> . This approach is standard, maintainable (Blender API exposes all you
> need, and Blender devs keep it working), familiar to Python coders in
> Blender and accepted by Blender devs (so they'll accept contributions
> this way).
>
> Regards,
> Michalis
>
>
>
>
> śr., 14 lip 2021 o 07:38 John Carlson <yottzumm at gmail.com> napisał(a):
> >
> > Does any one have experience with this python package and can recommend
> it?
> > https://pypi.org/project/blender-file/
> >
> > On Mon, Jul 12, 2021 at 9:54 PM John Carlson <yottzumm at gmail.com> wrote:
> >>
> >> My first thought is reading .blend files in c/c++ using SDNA.
> >>
> >> I’ve heard that .blend files are TLV, which leaves me to believe
> STEP/EXPRESS might be useful if binary is encoded in hexadecimal.   I will
> make an informed choice on ARM vs Intel endianness.
> >>
> >> I have downloaded the latest blender source code.
> >>
> >> So I will begin by tracking down how open files, and see what Blender
> does.
> >>
> >> John
> >>
> >> On Sat, Jul 10, 2021 at 5:19 PM John Carlson <yottzumm at gmail.com>
> wrote:
> >>>
> >>>
> >>>
> >>> I think Blender needs a JSON, XML, STEP/EXPRESS or python dict full
> export of .blend files.   I do not know if either Collada or glTF support
> that.  I will probably start working on a native UTF-8 export for Blender.
>  I believe that Blender will become more useful and open with a full, human
> readable export, similar to how NeXT’s .nib format got converted to .xib
> format.   I think there’s still plenty of room for things like typed arrays
> in webGL and webgpu.   I’m not opposed to dropping into JavaScript or
> shading language if they can be parsed with an import tool.
> >>>
> >>> So that’s what I’ll be pursuing.   I don’t think we’ll ever see a good
> X3D export from Blender unless the Blender team is convinced it’s useful,
> or if someone starts fresh with the newest Blender API.   I do see
> usefulness in “outing” the Blender format, and providing an upgrade path
> for Blender import/export tools.
> >>>
> >>> I’m guessing the final result will be something like STEP.
>  Alternatively, I may pursue a “class grammar” as popularized by Cameron
> Browne on the Ludii project.
> >>>
> >>> I hope to protect import/export tool writers from the versionitis of
> the Blender API.   If you’re a good designer or architect, I welcome your
> effort on my team.
> >>>
> >>>
> >>> John
> >
> > _______________________________________________
> > x3d-public mailing list
> > x3d-public at web3d.org
> > http://web3d.org/mailman/listinfo/x3d-public_web3d.org
>
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