[X3D-Public] Fwd: Re: [X3D] X3D HTML5 meeting discussions: Declarative 3D interest group at W3C

Kristian Sons kristian.sons at dfki.de
Wed Dec 22 00:43:04 PST 2010


Dear Chris,

thanks a lot for joining the discussion and for your precious input. 
Some of your points should definitly be integrated into the charter draft.

Let me comment some of your point from my view:

>
> I applaud your effort to start an XG. I hope you go into the effort with an open mind and don't instantly attempt to ratify some form of the X3D spec. I have long felt that the main flaw of X3D is the fact that it stands alone. It has its own parser, its own scripting, its own image and media handling, it own event model and its own DOM. The event model in particular is completely foreign to the HTML model. It is also too big, even in its most modest forms. Look at SVG. It has taken many years for it to get even a toehold in modern browsers and even those implementations (including the one in WebKit) are inefficient and slow.'

I am very glad you welcome our initiative. I guess most browser 
developers with 3D know-how are working on WebGL right now. That's 
probaby why a declarative approach is out of scope for most of them. I 
think WebGL lifts of in 2011 and applications and libraries pop up from 
everywhere. That is great! But according to the Hype Cycle there will 
also be the "Trough of Disillusionment". That might be a good starting 
point to deliver a declarative alternative for those applications that 
run better with it. But that will be soon. Thus I fully agree that we 
need a lean solution that leverages ALL existing technologies and is 
fastly implementable.

One of the reasons why we started the XG is, because we think that the 
HTML integration is the main focus point. It's not about ratifying X3D 
spec, X3DOM or XML3D. I think we have an excellent starting point with 
two approaches (XML3D and X3DOM), WebGL prototypes, native 
implementations in Chrome and Firefox and several plugin 
implementations. Thus we have some lessons learned. Now it's time to 
identify the requirements and based on that, we have to find an optimal 
solution for the Web. That's why we a looking for industry backup 
(probably another flaw of X3D) for our initiative and I think we are on 
a good way. So one topic will be to find a good technical solution, the 
other to show use-cases for declarative applications and to demonstrate 
the industry interest.

>
> I'm saying all this so hopefully you don't go down the path of trying to solve too many problems. One of the motivators of this message was because there are 2 references to WebGL in your document. In the first you stated how WebGL had deficiencies which motivated your XG, and in the other you state that APIs like WebGL are out of scope for your XG. This troubled me. New web technologies build on the existing specifications and implementations. You could base your work on WebGL and you would reduce your workload dramatically.

This is one of the main topics we discussed today during the telco. I 
think it was Anita who said mentioning WebGL in the "Out of Scope" 
section might be missunderstood, and here we go...  It's not WebGL that 
is out of scope. To develop an imperative API-approach is out of scope. 
Perhaps we should omit this point. The name of the XG already says it.

We should definitly take WebGL into account. I think WebGL is the 
enabler for our activities and without WebGL we would have a chance at 
all. I think especially the Typed Arrays is something that should work 
fluently between both approaches.

> One area where WebGL is deficient is in its inability to use CSS directly. Even if you make a node set like X3DOM, being able to use a CSS color property on one of those nodes is very difficult. It's not hard to read the color and apply that to a 3D primitive. But being notified that the color had changed, either by programmatically changing the style, or by animating the color with CSS Animation, is impossible. A huge advantage of a native node set is that such notification is easy and would provide great integration with the CSS style system of today's browsers.

The CSS integration is a tricky thing. It's powerful and well-known. 
It's perfect for a fixed-function rendering like HTML. But hard to merge 
this with the programmable 3D pipeline. In the XML3D project we use CSS 
to assign shaders to geometry but not for the generic shader parameters. 
I would really like to see a stronger CSS usage. On the other hand it 
makes it harder to protoype it with JS/WebGL.

So with your experience it would be nice to have you being involved in 
some way with the XG. As an external professional or with Apple. I know 
that you are very busy with WebGL. But at least getting your input as 
kind of reviewer would be extremely helpful!

Cheers,
   Kristian


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Kristian Sons
Deutsches Forschungszentrum für Künstliche Intelligenz GmbH, DFKI
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