Hi!

I just thought if it might be possible to use XML to describe a scene. 
In my opinion, this would have a lot of advantages: Namespaces, ability 
to transform whole scenes using XSLT and the ability to retrieve data 
from POVXML-files and use them somewhere else.

It wouldn't pose AFAIK any problem to write a XSLT-script that would 
transform an XML-document to POVRay file format. Obviously this works 
only in one direction. It is, however some work to do so since all 
POVRay features would have to be mapped to XML.

I'd like to know if there is already such a system planned or implemented.
If not: Is anyone except me interested in implementing such a system?

What do you think about this idea?

Thanks in advance
Bernd Fuhrmann

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Bernd Fuhrmann wrote:
> Hi!
> 
> I just thought if it might be possible to use XML to describe a scene. 
> In my opinion, this would have a lot of advantages:

In short: nothing prevents you from doing so (at least theoretically) 
but you should bear in mind the following thing: no one sane who uses 
POV-Ray for serious work will write a scene in XML or use XML to store 
scene data.  If you have trouble imagining why this is the case just 
have a look at Yafray.

Christoph

-- 
POV-Ray tutorials, include files, Sim-POV,
HCR-Edit and more: http://www.tu-bs.de/~y0013390/
Last updated 23 Sep. 2004 _____./\/^>_*_<^\/\.______

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Christoph Hormann wrote:
> In short: nothing prevents you from doing so (at least theoretically) 
> but you should bear in mind the following thing: no one sane who uses 
> POV-Ray for serious work will write a scene in XML or use XML to store 
> scene data.  If you have trouble imagining why this is the case just 
> have a look at Yafray.

I just had a look at it. Yafray seems to support only meshes. This is 
certainly not a good approach. This will lead to big XML files. XML as 
low level language can't be a good idea since processing speed does 
matter. But what about a high level XML representation? There wouldn't 
be that bad processing speed impacts.

On the other hand: The POVRay file format is not that open to 
extensions. There isn't a reasonable naming scheme which would allow to 
use codesnippets from all kinds of people in one single project. So for 
real big and long-term projects XML would definately be the markup 
language of choice.

Bernd Fuhrmann

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On Fri, 31 Dec 2004 10:02:16 +0100, Bernd Fuhrmann <Sil### [at] gmxde>
wrote:
> What do you think about this idea?

As Christoph said.

FYI: http://www.web3d.org/x3d/overview.html

ABX

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Bernd Fuhrmann <Sil### [at] gmxde> wrote:
> I just thought if it might be possible to use XML to describe a scene. 
> In my opinion, this would have a lot of advantages: Namespaces, ability 
> to transform whole scenes using XSLT and the ability to retrieve data 
> from POVXML-files and use them somewhere else.

  I really don't see those as advantages.

  No-one will write XML scenes by hand, so what's the point?

-- 
plane{-x+y,-1pigment{bozo color_map{[0rgb x][1rgb x+y]}turbulence 1}}
sphere{0,2pigment{rgbt 1}interior{media{emission 1density{spherical
density_map{[0rgb 0][.5rgb<1,.5>][1rgb 1]}turbulence.9}}}scale
<1,1,3>hollow}text{ttf"timrom""Warp".1,0translate<-1,-.1,2>}//  - Warp -

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Warp wrote:
> Bernd Fuhrmann <Sil### [at] gmxde> wrote:
> 
>>I just thought if it might be possible to use XML to describe a scene. 
>>In my opinion, this would have a lot of advantages: Namespaces, ability 
>>to transform whole scenes using XSLT and the ability to retrieve data 
>>from POVXML-files and use them somewhere else.
> 
> 
>   I really don't see those as advantages.
> 
>   No-one will write XML scenes by hand, so what's the point?

Why not? It isn't that difficult. People write XHTML, MathML and even 
SVG by hand. At least I do. So why not POVRay? There are a lot of 
advantages:

It would be possible to write material libraries, object libraries and 
so on without clobbering the global namespace.
It would become possible to access the camera settings to adjust certain 
values. This would make the implementation of HUD systems possible 
(useful if you want to mark or label certain things in your scene).

One could even convert whole models to meshes and apply mesh 
modificators on them. This is AFAIK not yet possible in POVRay.

Ok, maybe some of these things can be done in POVRay file format. But if 
they can be done, how clean can they be done?

Regards,
Bernd Fuhrmann

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Bernd Fuhrmann wrote:
>>
>>   No-one will write XML scenes by hand, so what's the point?
> 
> 
> Why not? It isn't that difficult.

That's not the point.  You can either take my word on it that people 
won't do it or ignore the fact - the result will be the same.  The same 
ideas are brought up from time to time in these newsgroups - 
interestingly usually not by people who use POV-SDL a lot.

You can easily find previous discussions on this matter by searching 
these newsgroups, for example:

http://news.povray.org/povray.general/thread/<Xns94B1A5863FF0DZenZenPsychocom%40203.29.75.35>
http://news.povray.org/povray.programming/thread/<38CE3B1A.80B4F27%40nigels.com>

Christoph

-- 
POV-Ray tutorials, include files, Sim-POV,
HCR-Edit and more: http://www.tu-bs.de/~y0013390/
Last updated 23 Sep. 2004 _____./\/^>_*_<^\/\.______

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On Fri, 31 Dec 2004 13:12:46 +0100, Bernd Fuhrmann <Sil### [at] gmxde>
wrote:
> Why not? It isn't that difficult. People write XHTML, MathML and even 
> SVG by hand. At least I do. So why not POVRay?

You know, there are a few not technical users of POV-Ray. While average
"artist" can easily write and understand sphere{0 r scale x*4 pigment{Red}}
anything more complicated would make understanding harder.

> It would be possible to write material libraries, object libraries and 
> so on without clobbering the global namespace.

You have material and object libraries nowadays in include files.
Can you point me an example of useful namespace application within POV-Ray
scene from average unskilled user point of view?

> It would become possible to access the camera settings to adjust certain 
> values.

See screens.inc include file solutions.

> This would make the implementation of HUD systems possible 

Head Up Displays you mean? Which application you mean exactly?

> (useful if you want to mark or label certain things in your scene).

? Anything you can't do currently?

> One could even convert whole models to meshes and apply mesh 
> modificators on them. This is AFAIK not yet possible in POVRay.

That depends what you mean by "convert" and "modificators".
ie. http://www.geocities.com/SiliconValley/Lakes/1434/images/createmesh.jpg

> Ok, maybe some of these things can be done in POVRay file format.

IMO that's not POV-Ray file format but POV-Ray features which makes things
possible.

> But if they can be done, how clean can they be done?

Some prefer question: how hard can they be done. I think writing simple
include file is easier than introducing new parser and changing habits of
large community.

ABX

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in news:s1hat0h78j5s8q34g4e8308c8aubiv6230@4ax.com ABX wrote:

> Can you point me an example of useful namespace application within
> POV-Ray scene from average unskilled user point of view?
> 

A problem I ran into several times is using multiple include files, where 
in two or more inc's objects are defined with the same name.

Ingo

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On 31 Dec 2004 07:54:35 -0500, ingo <ing### [at] tagpovrayorg> wrote:
> > Can you point me an example of useful namespace application within
> > POV-Ray scene from average unskilled user point of view?
>
> A problem I ran into several times is using multiple include files, where 
> in two or more inc's objects are defined with the same name.

And usually how hard it is to solve such issue?

ABX

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