[x3d-public] Fwd: thinking about X3DJSONLD/X3DOM/glTF interoperability

[Leonard Daly]

John,

> XSeen is taking the approach of treating glTF as a model.   What are 
> others doing?  Is anyone considering the whole scenegraph?  Why or why 
> not?  Is glTF as a model done because Three.js treats glTF as a mesh 
> (I don't know if three.js does this or not)?

XSeen and A-Frame both use the glTF loader for THREE. The loader imports 
the entire model and texture (a mesh in THREE terminology). Both also 
include all of the animations and any scene graph structure. However, 
that structure (including animations) is sort-of encapsulated from the 
rest of the scene graph. There are no events that are fired during 
animation sequences.

X3DOM treats the glTF file as what can be represented in a single Shape 
node - geometry + appearance. Transforms and animation are not included.


>
> What do people think of the low level nature of glTF as opposed to X3D?

glTF ranges from low-level (geometry + basic appearance) to full scene 
graph. I am not sure how to interpret your question.

glTF is becoming the standard exchange format. It includes (more or 
less) everything in FBX, but it is open. It has more options than OBJ, 
and is smaller in size. I think it is necessary to be able to process 
glTF and include it in a scene graph, much like the glTF importer for 
THREE. Yes, it does overlap with X3D.


> While it makes it less understandable, I can see how keeping glTF low 
> level would improve performance at the expense of file size.   Has 
> anyone compared and contrasted the two standards?

Which two standards - X3D & glTF? glTF has better animation, it has been 
adopted by more users and content creators (people & software). It comes 
in a binary and text forms. It has the potential for being the entire 
scene graph. It includes shaders and advanced appearance (bump maps, 
ambient occlusion, etc.).

On the downside, I don't think it has audio, movie textures, 
environmental effects (fog, background, etc.), or sensors. I may be 
wrong about some of these items because I haven't studied glTF in its 
entirety -- I just haven't come across those capabilities yet.

>
> Are there glTF importer/exporters for blender yet? If not, why not?

There will be a BOF at SIGGRAPH about Blender exporters including a glTF 
exporter. I am not sure about an importer. Since there is a THREE 
loader, I suspect it would not be that difficult to build an importer.


Leonard Daly



>
> John
>
>     I’m thinking about glTF and X3DJSONLD interoperability since X3DOM
>     is starting to support glTF (I think).  What do you think the
>     synergies might be?
>
>
>
> _______________________________________________
> x3d-public mailing list
> x3d-public at web3d.org
> http://web3d.org/mailman/listinfo/x3d-public_web3d.org


-- 
*Leonard Daly*
3D Systems & Cloud Consultant
LA ACM SIGGRAPH Chair
President, Daly Realism - /Creating the Future/
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://web3d.org/pipermail/x3d-public_web3d.org/attachments/20170706/9e95a45a/attachment.html>