[x3d-public] Purpose of X3D

[Joe D Williams]

Hi Leonard,

----- Original Message ----- 
From: "Leonard Daly" <Leonard.Daly at realism.com>
To: "X3D WG" <x3d at web3d.org>; "X3D Public" <x3d-public at web3d.org>
Sent: Thursday, October 06, 2016 10:21 AM
Subject: [x3d-public] Purpose of X3D


>I have been struggling with this topic for several months -- what is 
>the
> purpose of X3D in the electronic ecosystem of the 21st century. The
> Consortium says that "X3D is a royalty-free open standards file 
> format
> and run-time architecture to represent and communicate 3D scenes and
> objects using XML" [http://www.web3d.org/x3d/what-x3d]. As an ISO
> standard, X3D needs to have a long shelf-life, contain 3D models,
> animation, and interactivity; and communicate this within and 
> between
> systems using XML.

OK, that works for me.

> To do this effectively, it needs to stay current with
> industry practices while maintaining an ability to communicate
> information from the past.

I think the best and maybe only way X3D can effectively stay current 
with industry (best) practices is when industry and academia 
contributes the royalty-free techniques and technology. For example, 
various image processing techniques that may be proprietary and only 
can do only on certain $$ stations. If info is open, X3D can implement 
available and desirable open techniques and technology.

See CAD and HAnim and Medical for latest.

>
> There is no question about X3D's handling of old data. To my 
> knowledge
> there is no other 3D system that can display models, animation, and
> interaction from 15+ years ago. In the Internet age where half-life
> appears to be around 18 months, that is a remarkable achievement.

Yes, and one that can be maintained as long as it is general and 
widely usable.

>
> X3D has not kept up with current practices in modeling, animation,
> rendering, or interaction.

Here is where we need the list of old vs new.

> modeling, animation, rendering, or interaction.

Great, those would seem to be the big ones.
In all cases I would like to keep the focus on realtime.
All other needs for animation and rendering for video or film can be 
accomplished if we carry on with a robust realtime system where robust 
means confident author controlled event ordering.

> Work on the most recent update to X3D (V3.3 -
> 2013) started back in 2009 and the document was mostly completed in
> 2010. The most advanced feature is 3D volume rendering.

Maybe the most advanced for X3D means latest for which open free 
access backed by a working implementation is obtained.

> Work on particle
> systems and physics is several years before that.

> The standard for
> animation of any model is with bones and rigs - whether that model 
> is a
> character, a tree, or a machine.

True and for X3D HAnim we expose it all including skin and animation 
bindings.
The bones are HAnim Segments and the HAnim Joint is directly exposed 
to the user.

Here the term rigs will mostly mean binding the 'skin' mesh to various 
Joints (same as 'bones' in this) or other mesh animation devices 
(DIsplacer) or coordinate or whatever interpolaters so that the 
surface features move as desired when the skelton is animated by Joint 
rotation (same as bone orientation), or if just a mesh feature is 
animated independently.

A more simple form of a rig would be where only Segment (same as bone, 
if you wish) geometries are used and no skin.

Doesn't matter, X3D HAnim does all that.

Of course we can also create and rig a deformable mesh skin to a 
skeleton by nominating vertices from various segment geometies.

> All current renders use shaders (code
> that runs on a graphics card) to create highly realistic (or 
> fantastic)
> surface appearance.

That is why X3D has some interfaces dedicated to shaders.
We should try to pick up support for any 'new' shaders used by the cl, 
webcl, gl, and webgl.

> Work on upgrading interaction to support mobile
> devices (including multi-touch), head-mounted-displays including 
> game
> controllers, paddles, LEAP interfaces, and other specialized devices 
> is
> just beginning.

Yes, see MARS stuff, and also CAD advances. Not to mention GEO

>
> So back to my question -- what is X3D for? In 20 years time will the
> only content for X3D be 35 years old? Current content not created
> explicitly for X3D won't work because X3D does not support much more
> than static modeling.

What features are missing from X3D in order to support content that 
will need to be created 5 years from now?

Certainly we can see that X3D uses best practices currently available 
free for use in X3D that can produce immersive interactive 
simulations. We may be seeing new ideas about GPU runtime storage of 
data such as animations, and new ideas about how to organize the user 
code for more direct GPU (parallel) processing. X3D scripts and 
shaders should have WebGL probably need CL and WebCL for future 
computational modeling enhancements.

>
> I have collected several choices. These are described below in more 
> or
> less least to most complex (aka work). There are a lot of other 
> options,
> more towards bottom of the list. If you have other contributions, 
> please
> feel free to state so along with what you think it would take to get
> there from X3D V3.3.
>
>  1) X3D is for static models only (no texture). This is a very good
> match. There are just a few things that X3D doesn't handle and most 
> of
> those are having to deal with interchange with other formats.
>  2) X3D is for static models + appearance. X3D needs to expand to 
> make
> full use of appearance shaders of all sorts.

I think there are couple of different types of shaders

>  3) X3D is for models including animation. X3D needs to expand to
> include at least the current practice of skeletal structure plus 
> rigging
> (attaching surface weights to various joints). This is not H-Anim, 
> but
> broader as it includes models that are not even at all human,
> human-like, animals, or even "living".

Please have a solid look at X3D HAnim.

> include at least the current practice of skeletal structure plus 
> rigging
> (attaching surface weights to various joints).

What part(s) of that is not fully specified lin X3D HAnim?

> skeletal structure

OK, best practice by X3D.

> skeletal structure plus rigging

OK, best practice by X3D.

> > (attaching surface weights to various joints).

Well, the idea is accomplishing movement of one or a set of vertices 
by weighted rotation of bound Joint(s). For example, if the weight is 
0.5 then the vertex would be moved according to 0.5 of the Joint(s) 
rotation.

I think this is the most simple capability since various weighting 
equations may be use, but this is all linear.

> This is not H-Anim,

what? X3D uses best practice skeletal structure and animation 
hierarchy with both skin and segment geometry and the complete 
documentation for the weighted skin bindings. Some might be confused 
at first if they have access to Joint rotation rather than hidden 
behind bone orientation (luckily they are the same) and the tediously 
complete documentatinon of the bindings.

What do you need that is not there in HAnim now?

>  4) X3D is for runtime display. X3D needs to include all major 3D
> formats.

And those major formats are:


it is interesting that right now we are dealing with importing a 
'major' animation data format for use in X3D. I think we will find 
that when we want to import another data structure than is native in 
X3D, we first need to settle on some 'standard' form of the input. 
That is mostly hard to do but is necesary in order to provide the X3D 
standard output.

Currently the best target formats to include is the gl and the cl, 
Collada, and glTF (including SRC). X3D shouldhave a running project to 
track thier progress and encourage implementation by X3D toolmakers. 
Almost full-time work for somebody. :

> It needs to run AND use interface mechanisms of all major
> platform types, including phones/tablets, HMDs, desktops, etc. It 
> needs
> to run in a browser: it needs to run as an app.

Once there was a long way between what we could expect from a higher 
perfomrmacne desktop or dedicated workstation and what we expect from 
our phones. How to keep up?


>  5) X3D is everything. Well, think about that for a moment. That 
> means
> all of the above need to be done. It also needs to be widely 
> adopted,
> and this needs to be completed in the next 12-18 months. It would
> probably take a team of 20-50 people working on a specification,
> implementations, conversion, integration applications, marketing, 
> etc.
> to accomplish this.

Well, fortunately the HAnim is not so far off as you portray above.
So those people worried about that can look at deeper stuff missing 
than the basic set of features (in five objects) we have.

> Advocates for this choice need to have a reality check.

Also a good virtual realilty check, for available technology and 
techniques.

>
> Given that we have maybe 7 part time people (right now) where does 
> X3D go?

Well, pick something that would improve the way you can use X3D.
Join a working group or create a new one and start a Working Draft and 
some sort of implementation or proof of that feature set. If it is 
good, then it will advance within the consortium. If people or 
resources are outside the consortium member structure, then ask x3d wg 
or bod for options.

i still think there will be need for a sort of 2 levels for X3D.

First is the stand-alone desktop features and performance available 
from an optimized X3D runtime running in the host OS for max 
preformance.

Second is the x3d runtime available when running as a web page under 
control of the browser. For sure this is getting better all the time 
but still, for our our own entertainment and the (at least) order of 
magnitude improvement running standalone, incidentally supporting html 
as some elements of the scene, and we want to maintain the truely 
robust, high performance event system concept of a standalone X3D 
browser running the scene.

Thanks, Leonard,
All Best,
Joe

>
> -- 
> *Leonard Daly*
> 3D Systems & Cloud Consultant
> LA ACM SIGGRAPH Chair
> President, Daly Realism - /Creating the Future/
>


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