[x3d-public] Css-3d tags

[Andreas Plesch]

There is a dedicated page:

http://xml3d.org/xml3d/papers/css-integration/

with a link to the paper.

This is a full treatment of considering the Appearance of an object as a
style without really considering if Appearance is equivalent to the style
concept. It is somewhat doubtful that in graphics the appearance of a model
can be meaningfully separated from what the model represents, eg. its
semantic content. It is a rare situation for which it would be acceptable
to replace a wooden chair with a plastic chair without consequences for how
the scene is understood.

The authors seem to acknowledge that because they start to discuss clean
reuse of assets, and consider CSS use in that context, just as Leonard
points out with DEF/USE. But this opens the door to consider dedicated
asset management such as aframe's asset tag. Consequently, Leonard's
proposal seems to parallel that concept. While CSS may be helpful in reuse,
there may be other and more suitable ways such as DEF/USE or a special
asset node or protos. The main drive to use CSS then becomes to take
advantage of its good support in browsers, and perhaps familiarity.

I guess I am still trying to understand why there is this demand for CSS in
declarative 3d. I think aframe does not support styling ?

-Andreas







On Fri, Sep 22, 2017 at 2:09 PM, Nicholas Polys <npolys at vt.edu> wrote:

> This is a good paper
> describing some other possibilities for conceptualizing 'styling'
>
> Jan Sutter, Kristian Sons, and Philipp Slusallek. 2015. A CSS integration
> model for declarative 3D. In *Proceedings of the 20th International
> Conference on 3D Web Technology* (Web3D '15). ACM, New York, NY, USA,
> 209-217. DOI: http://dx.doi.org/10.1145/2775292.2775295
>
>
>
> On Fri, Sep 22, 2017 at 2:00 PM, Leonard Daly <Leonard.Daly at realism.com>
> wrote:
>
>> Andreas,
>>
>> This looks very interesting. I will need to spend some time on it to make
>> sure I fully understand it.
>>
>> I too struggled with understanding "style" in 3D. There is a style to
>> films (and the CG in it) that might be used. I think another way to think
>> of things is as like DEF/USE. The <class3d> tags define the DEF and they
>> are used in class3d='...'. I have not tried to think through all of the
>> potential DEF/USE cases to see what does and does not work. So far I do
>> know that it should work for all Appearance related properties (Material,
>> ImageTexture, etc.). XSeen does not support modeling (models are imported),
>> so geometry constructions are not relevant. Animation is the other big
>> area. I don't know about that one yet. I am working on revising the simple
>> animation capability and will find out later.
>>
>> Leonard Daly
>>
>>
>>
>>
>> In Leonard's nomenclature classes are collections of specific styles.
>> This is in contrast to HTML where classes are collections of elements.
>> Nevertheless, here is a potential way to use paths or any css selector to
>> assign styles to matching elements in a preprocessing phase. Say there is a
>> tag such as
>>
>> <css3d objects=selectorString styles='shape box' />
>>
>> where shape and box are defined class3ds.
>>
>> Then in a preprocessing step it would be possible to go through all css3d
>> elements, select matching target elements and add a class3d='shape box'
>> attribute to each. In pseudocode:
>>
>> document.querySelectorAll('css3d').for each(function(El){
>> styles=El.styles
>>
>> document.querySelectorAll(selectorString).for
>> each(addclass3d.bind(styles))
>>
>> )})
>>
>> function addclass3d(El) {
>> El.setAttribute('class3d', this)
>> \\better merge into existing value
>> }
>>
>> This is rough but could work I think.
>>
>> The larger question if it is possible to separate semantic content from
>> presentation in 3d scenes. Is geometry always content and size or color
>> always style ? Are small animations always just a stylistic aid, never
>> critical ?
>>
>> In HTML CSS is mostly used to make pages 'pretty' and sometimes look
>> coherent across a larger site. What is the equivalent use for 3d scenes ?
>> Perhaps this suggests that css would be most useful if it worked across
>> multiple scenes ?
>>
>> Andreas
>>
>>
>>
>>
>>
>>
>> _______________________________________________
>> x3d-public mailing listx3d-public at web3d.orghttp://web3d.org/mailman/listinfo/x3d-public_web3d.org
>>
>>
>> --
>> *Leonard Daly*
>> 3D Systems & Cloud Consultant
>> LA ACM SIGGRAPH Chair
>> President, Daly Realism - *Creating the Future*
>>
>> _______________________________________________
>> x3d-public mailing list
>> x3d-public at web3d.org
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>>
>>
>
>
> --
> Nicholas F. Polys, Ph.D.
>
> Director of Visual Computing
> Virginia Tech Research Computing
>
> Affiliate Professor
> Virginia Tech Department of Computer Science
>



-- 
Andreas Plesch
Waltham, MA 02453
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