[x3d-public] Physically Based Rendering gltf examples in .x3d form; design approach confirmed, encourage X3D4 implementation

Tue Sep 29 17:36:29 PDT 2020

If someone can provide a file with conversion from glTF to .x3d, I can
write a quick batch converter which can be integrated into ant (or I can do
X3DJSONLD shell script version and Don can do the sourceforge build.xml
version).   Do we currently have a place to drop the converted files?
 What's the Khronos license like?

The converter should be something like:

php converter.php < in.gltf > out.x3d

or

php converter.php -in in.gltf -out out.x3d

I'm pretty sure this has been shown before, but I don't know the specifics
on what files to run on my local system.
Thanks,

John

On Tue, Sep 29, 2020 at 5:55 PM Michalis Kamburelis <
michalis.kambi at gmail.com> wrote:

> Thank you Andreas!
>
> Yes, we'd like to show in X3D examples some glTF + corresponding X3D
> files. That would be a confirmation of my prose on
> https://github.com/michaliskambi/x3d-tests/wiki/Converting-glTF-to-X3D
> , that describes the conversion with words instead of examples. In
> particular some examples from
> https://github.com/KhronosGroup/glTF-Sample-Models/ .
>
> As for the particular lizardman from
>
> https://github.com/michaliskambi/x3d-tests/tree/master/pbr/physical_material
> : That lizardman demo is more problematic, there is no exact glTF
> equivalent to the X3D version there. The lizardman in X3D was created
> in the old Blender version, that could export to X3D with textures.
> For the new Blender (2.8), and lizardman in glTF, the model was
> reworked. Alas, new Blender (since 2.8) has broken X3D exporter that
> doesn't export textures at all. In effect, I have 2 different
> lizardman versions:
>
> - old one, generated from old Blender to X3D
>
> - new one, that can be opened in new Blender and works and can be
> exported to glTF (but not to X3D...)
>
> So the lizardman is not the best case for comparison anymore, sadly.
>
> Regards,
> Michalis
>
> śr., 30 wrz 2020 o 00:06 Andreas Plesch <andreasplesch at gmail.com>
> napisał(a):
> >
> > Thanks for the report ! Michalis, would it be possible to provide gltf
> > versions of the examples in:
> >
> >
> https://github.com/michaliskambi/x3d-tests/tree/master/pbr/physical_material
> ?
> >
> > It looks like the existing lizardman.gltf is the base for the
> > lizardman variations but does not quite match them. The occlusion
> > textures is used as the basecolor texture and the lights seem
> > different.
> >
> > Since one of the main use cases for PhysicalMaterial will be glTF
> > import and inlining, it would be really useful to have that two way
> > ability to confirm high fidelity rendering between glTF and x3d
> > renderers. For example, x_ite and x3dom already have gltf renderers
> > (but not the PhysicalMaterial node).
> >
> > Conversely, it would be similarly useful to convert standard glTF
> > examples (like the Avocado, they have all liberal licenses) to the new
> > PBR nodes. In fact, view3dscene likely already does this internally to
> > render gltf. So it may be mostly a matter of exposing the internal
> > nodes.
> >
> > -Thanks, Andreas
> >
> > On Tue, Sep 29, 2020 at 1:18 PM Don Brutzman <brutzman at nps.edu> wrote:
> > >
> > > Meeting today: Michalis Dick Don, regrets (and feedback) from Andreas.
> > >
> > > Michalis has the following .x3dv examples prepared:
> > >
> > > [6] michaliskambi > x3d-tests > pbr
> > >      https://github.com/michaliskambi/x3d-tests/tree/master/pbr
> > >
> > > He graciously agreed to export XML .x3d versions as well so I don't
> spend time (or make errors) transcribing them in preparation for regression
> testing.
> > >
> > > He will also add screenshots for each model so that everyone knows
> what expected rendering looks like.
> > >
> > > We hope that this really facilitates other X3D4 implementations and
> encourages consistent presentation.
> > >
> > > The above examples are all authored by Michalis and in open source,
> some textures are by others and given appropriate credit.
> > >
> > > On 9/29/2020 7:32 AM, Don Brutzman wrote:
> > > > With X3D XML Schema and DOCTYPE complete, and X3D Schematron rules
> addable without too much difficulty, we're ready for next steps.
> > > >
> > > > As part of examples improvements, am hoping to put them in our
> archives so that regression testing can be performed.
> > > >
> > > > [1] X3D Resources, Example Archives
> > > >
> https://www.web3d.org/x3d/content/examples/X3dResources.html#Examples
> > > >
> > > > May I suggest that we create an PhysicallyBasedRendering section
> directory for these at
> > > >
> > > > [2] X3D for Advanced Modeling (X3D4AM) Examples Archive
> > > >      https://x3dgraphics.com/examples/X3dForAdvancedModeling/
> > >
> > > We agreed to put copies of them there, matching and in open source (of
> course).  Thank you Michalis.
> > >
> > > > Wondering, where might I find the examples you've shown?  Am looking
> at
> > > >
> > > > [3] michaliskambi > x3d-tests >
> > > >      Include PBR (PhysicalMaterial and related concepts) in the
> official X3D specification
> > > >
> https://github.com/michaliskambi/x3d-tests/wiki/Include-PBR-%28PhysicalMaterial-and-related-concepts%29-in-the-official-X3D-specification
> > > >
> > > > and then
> > > >
> > > > [4] michaliskambi > x3d-tests > Converting glTF to X3D
> > > >
> https://github.com/michaliskambi/x3d-tests/wiki/Converting-glTF-to-X3D
> > > >
> > > > and then
> > > >
> > > > [5] castle-engine > demo-models > glTF > sample models for Castle
> Game Engine
> > > >      https://github.com/castle-engine/demo-models/tree/master/gltf
> > > >
> > > > Wondering how to establish a baseline.  Might it be possible to use
> Castle Engine to Inline load each of these gltf examples and save each one
> of them back out as X3D?
> > >
> > > He confirmed that, rather than Inline (which would be preserved
> verbatim on saving) it is possible to
> > > - open a glTF model in view3dscene, then
> > > - save as X3D
> > >
> > > An update to the following converter is in progress to match the
> latest X3D4 node signatures, will be finished soon.  At that point anyone
> can perform this step via
> > >
> > > [7] Castle Game Engine: Convert everything to X3D
> > >      https://castle-engine.io/convert.php
> > >
> > > We will work on those Khronos-provided glTF examples after adapting
> his existing examples for regression testing.
> > >
> > > > Primary format in the example archives is XML .x3d file encoding,
> preforming maximum validations, then all other variants are then converted
> from that in order to check proper X3D representations in X3DOM, X_ITE,
> ClassicVRML, JSON, EXI, Java, Python, Turtle, and pretty-print HTML
> documentation.
> > >
> > > Interestingly X_ITE and X3DOM versions are automatically provided as
> part of this Web3D Examples Archive endeavor.  Helpful for checking.
> > >
> > > > Looking forward to getting into pair-wise production and publication
> together.
> > > Additional implementations: the past week's work on XML Schema and
> X3DUOM have each provided significant implementation checks that the
> interface hierarchy is coherent and consistent, without internal
> contradictions.  X3D Tooltips add clarity and link to various
> representations.  X3D Validator provides error checking.
> > >
> > > [8] X3D Specifications: Schema and DOCTYPE Validation
> > >      https://www.web3d.org/specifications
> > >
> https://www.web3d.org/specifications/X3dSchemaDocumentation4.0/x3d-4.0.html
> > >
> https://www.web3d.org/specifications/X3dDoctypeDocumentation4.0.html
> > >
> > > [9] X3D Unified Object Model (X3DUOM) v4
> > >
> https://www.web3d.org/specifications/X3dUnifiedObjectModel-4.0.xml
> > >
> > > [10] X3DJSAIL: X3D Java Scene Access Interface Library
> > >       https://www.web3d.org/specifications/java/X3DJSAIL.html
> > >
> > > [11] X3D Validator
> > >       https://savage.nps.edu/X3dValidator
> > >
> > > Next: Dick and I will work on clarifying X3D4 specification prose
> further in a follow-on session this week.
> > >
> > > The three of us all think it is fair to say that the PBR design is now
> complete and correct.  All of our major questions are answered
> satisfactorily. We are next pursuing implementation and evaluation of
> examples to confirm that conclusion. This work is already implemented in
> open-source Castle Game Engine / view3dscene.
> > >
> > > Suggest that other rendering implementations can now proceed with a
> high degree of confidence that integration of glTF, physically based
> rendering (PBR) and non-photorealistic rendering (NPR) is feasible and
> ready for implementation by other X3D4 players.
> > >
> > > Again thanks to Michalis for superlative design/implementation
> efforts, again thanks to everyone who helped with many questions critiques
> and contributions.  Totally impressive team effort.
> > >
> > > On our way... Have fun with advanced rendering in X3D4!!  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
> >
> >
> >
> > --
> > Andreas Plesch
> > Waltham, MA 02453
>
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