[X3D-Ecosystem] [x3d-public] gltf for Humanoid loa4 level 1

Tue Jul 30 19:00:16 PDT 2024

Sorry Joe, I really have difficulty looking at anything that’s not email,
API, VRML, XML, JSON or program code.

I don’t see how the JSON examples you link help me understand.  Do you have
a full JSON animation example?

On Tue, Jul 30, 2024 at 7:42 PM Joe D Williams <joedwil at earthlink.net>
wrote:

> > Perhaps a next step is to provide an HAnim to glTF mapping.
>
>
>
> that is what I am talking about. Please take a look at the gltf tutorial
> link and see what you think.
>
> It is easy to see that the gltf asset file(s) can be created from x3d
> content and that gltf ascii can be created with text editor.
>
>
>
> All Best,
>
> Joe
>
>
>
>
>
> -----Original Message-----
> From: John Carlson <yottzumm at gmail.com>
> Sent: Jul 30, 2024 5:29 PM
> To: Extensible 3D (X3D) Graphics public discussion <x3d-public at web3d.org>
> Cc: Joe D Williams <joedwil at earthlink.net>, <hanim at web3d.org>, <
> x3d-ecosystem at web3d.org>
> Subject: Re: [x3d-public] gltf for Humanoid loa4 level 1
>
>
> Joe, we’ve discussed how Blender conversions of animation in X3D to glTF
> get played in various X3D browsers.  Feel free to import as VRM [ sic ] and
> export as glTF.  Feel free to import as BVH and export as glTF.
>
> Vince has tried to get X3D meshes converted to glTF with a stylesheet.
>
> We’re kind of waiting on the folks who do conversions from X3D to STL to
> produce X3D to glTF.  Triangles and transforms are not an HAnim solution.
>
> Using the OOTB blender x3d importer is a non-starter since it doesn’t
> import HAnim.  This might change, but I’m not seeing Blender people wanting
> to help with X3D.
>
> There may be other Blender importers.
>
> There may be online X3D to glTF converters.
>
> glTF interactivity extension may be right around the corner.
>
> Perhaps a next step is to provide an HAnim to glTF mapping.
>
> On Tue, Jul 30, 2024 at 6:57 PM Joe D Williams via x3d-public <
> x3d-public at web3d.org> wrote:
>
>>
>>
>> https://github.khronos.org/glTF-Tutorials/gltfTutorial/gltfTutorial_002_BasicGltfStructure.html
>>
>> gives some example tutorials with some user code. Even shows skinning
>> with a simple set of rotation transforms.
>> At least gltf is down to it and doesn't mind calling a joint a joint as
>> the primary animation driver.
>>
>> Image 2a: The glTF JSON structure
>>
>> and following summary of elements text shows x3d we have everything
>> needed to transcode hanim skeleton(s), geometries, and animations from x3d
>> hanim to gltf and back. Well, not quite transcoding, because some level of
>> relatively simple computational text name and value transformations might
>> be needed to match x3d native xml nodes and fields to native gltf node and
>> field names and content.
>>
>> This is to be expected, because x3d hanim nodes and fields and SAI are
>> meant to be best authortime in terms of basic human-readable syntax,
>> hierarchies, data stuffing, and realtime event processing, while the gltf
>> has no 'runtime' or event system of any kind that I have seen. So our gltf
>> oriented more toward the idea that the x3d hanim authortime has made it
>> possible to simply reorganize or even precompute gltf data structures and
>> elements for best transport and to optimize realtime delivery by the
>> expected host runtime.
>> Or, even transport to another gltf or x3d authortime.
>> In fact the interchangability of using basic standard native gltf assets
>> integrated with x3d native assets in a 'live' x3d authortime is handled
>> just fine using standard x3d SAI.
>>
>> Image 2b: The glTF structure
>>
>> Gives a bit more detail about how a set of assets, even a single file of
>> multiple embedded or in local or remote files of assets can be documented.
>> Again, the basic is the 'scene' and it is composed of strongly typed but
>> very versatile nodes and fields, some represented as buffers that appear to
>> have few default definitions, but can be derived by the x3d definition of
>> its SF form and content. So, for a gltf source collection of names and
>> data, by the time it gets to the gltf it better be ready to execute without
>> much ado. That is why x3d xml schema validation of the original input can
>> be important and that comparable schema validation for the gltf json form
>> be developed to the same degree.
>>
>> On and on through the tutorial and we see that like I said, there appear
>> to be few defaults, like gltf may not be aware or types like MFvect3F, you
>> must tell the name and parameter and how to interpret and access the data
>> structure for every element. However, we are happy to see some familiar
>> names for things like skin and joints
>>
>> Not to worry because the x3d native data, or data the live browser
>> runtime would have to compute anyway for data is very well known and
>> literally every standardized gltf asset definition is covered by x3d node
>> and data types.
>>
>> Has anyone tried a conversion of an example hanim model into a single or
>> set of gltf asset files?
>> Attached is most simple loa4 with small geometry and basically just the
>> skeleton Joint, Segment, Site nodes and measurements.
>> We need an loa4 because lower loas can be easily found by reduction.
>>
>> The top reason for HAnim is transportable animations. The gltf can
>> accommodate and even accelerate this good thing. It providing a very
>> condensed form for a 'standard' skeleton hierarchy with realistic and
>> custom dimensions then import realistic 'standard' and custom animations
>> (learn unit quaternions, not hard just something about cosines and half
>> angles and square roots?) along with geometry and behaviour accessories
>> faster and easier and more reliably for interactive operations in a
>> 'standard' time and event-driven virtualized environment.
>>
>>
>> please note: "The local transform matrix always has to be computed as M =
>> T * R * S."
>> also see:
>> https://www.web3d.org/documents/specifications/19775-1/V4.0/Part01/components/grouping.html#Transform
>>
>> If you want to know about x3d hanim Displacers, check out gltf sparse
>> accessors.
>>
>>
>> https://github.khronos.org/glTF-Tutorials/gltfTutorial/gltfTutorial_007_Animations.html
>>
>> Some artifacts move around using the basic stuff of x3d. True, it is like
>> gltf is made for convenient use by x3d and www.
>> Because it is.
>>
>> Thanks and Best,
>> Joe
>>
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>
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