Ron Parker <par### [at] fwicom> wrote:
: Other suggestions have included creating a plugin interface that
: allows for compiled shaders in shared libraries, or in Java classes.
: Unfortunately, neither of those solutions scales to every platform
: POV supports (DOS has no Java, apparently, and definitely no shared
: library support.)

  Also shared libraries (which I suppose is compiled code) of one platform
will not work in another.

  The programmable shaders are an interesting feature, though. There still
are things that are impossible, or at least extremely hard and/or slow to
make with the current textures. The solution so far has been to add more
and more pattern types to the povray core. This is not a very good solution
in the long run.
  This effect can be seen in Moray. Since it lacks a scripting language,
each time you want to do something not directly supported you have to
make/download a plugin that does it. If you want to do something slightly
different you have to make a new plugin or modify an existing plugin.
This results in megabytes and more megabytes of plugins in a chaotic
jungle of little files. If this continues enough, Moray and all its plugins
will take Gigabytes of space with all the resource and maintenance problems.
  A powerful scripting language would take some tens of kilobytes of code
and no amount of plugins would be enough to achieve the same functionality.

-- 
main(i,_){for(_?--i,main(i+2,"FhhQHFIJD|FQTITFN]zRFHhhTBFHhhTBFysdB"[i]
):5;i&&_>1;printf("%s",_-70?_&1?"[]":" ":(_=0,"\n")),_/=2);} /*- Warp -*/

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Nieminen Juha wrote:
> 
> Ron Parker <par### [at] fwicom> wrote:
> : Other suggestions have included creating a plugin interface that
> : allows for compiled shaders in shared libraries, or in Java classes.
> : Unfortunately, neither of those solutions scales to every platform
> : POV supports (DOS has no Java, apparently, and definitely no shared
> : library support.)
> 
>   Also shared libraries (which I suppose is compiled code) of one platform
> will not work in another.
> 
Yes, it is compiled, but it is more like Java's bytecode or some
assembler. So portability will not be an issue.

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Ron Parker wrote:
> 
> On Thu, 02 Sep 1999 09:50:26 -0700, Ken wrote:
> >
> >
> >Vahur Krouverk wrote:
> >
> >> Well, indeed it is done already, but this page seems to be really old
> >> and seems like he haven't published source code. Does anyone have
> >> contact with him?
> >> At least this page shows, that shaders in POVRay are possible...
> >
> >I have no more data than what I provided. Did you search the site ?
> >This was allegedly accomplished with a Pov v2.2 patch and the source
> >should be available somewhere.
> 
> The source was on the old ftp.povray.org, and is still on ftp.cdrom.com
> in /pub/povray somewhere.  Nobody's ever gotten it to compile and run
> properly, and it's not been ported to 3.x.  It's also got some severe
> limitations, among them the fact that it doesn't support uv mapping and
> the derivative stuff from SL.  Those things are both fairly vital, so
> the average SL texture from the net wouldn't be usable.
> 
> However, with Nathan's UV patch (especially if we all pitched in and
> extended it to the objects that still need it) and the information in
> the '99 SIGGRAPH paper on tracing Ray Differentials, it could almost
> work.  It's still a lot of work, and you'd probably want to ignore
> POVMAN and just start over.
> 
Can you point out, in which paper it was? How can I see it? Can You send
me a copy or if it is not possible (due to copyright), then how can I
purchase this paper (preferably online, assuming that it does not cost
me arm and leg). I'm not saying, that I will start implementing of
shader, I'm just curious. Although...

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On Thu, 14 Oct 1999 21:31:39 +0300, Vahur Krouverk wrote:
>Ron Parker wrote:
>> However, with Nathan's UV patch (especially if we all pitched in and
>> extended it to the objects that still need it) and the information in
>> the '99 SIGGRAPH paper on tracing Ray Differentials, it could almost
>> work.  It's still a lot of work, and you'd probably want to ignore
>> POVMAN and just start over.
>> 
>Can you point out, in which paper it was? How can I see it? Can You send
>me a copy or if it is not possible (due to copyright), then how can I
>purchase this paper (preferably online, assuming that it does not cost
>me arm and leg). I'm not saying, that I will start implementing of
>shader, I'm just curious. Although...

http://www-graphics.stanford.edu/papers/trd/

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