Vahur Krouverk wrote:
> 
> Hello!
> 
> Finally I've decided to release my custom patch of POV-Ray, called
> POVMan. 

I "only" discovered it today, and all I have to say is : GREAT !!!
Thank you very much for doing that, it will be highly useful !

(now, the "but BMRT has shading language" argument is down :-))

Fabien.

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Well! Looks like there's a *lot* of interest in this particular patch!
I, for one, rejoice--I have long wanted a version of POV with the
renderman shading language. Great job, Vahur Krouverk! :) And thank
you!


--Richard Adams

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Fabien Mosen wrote:
> 
> (now, the "but BMRT has shading language" argument is down :-))
Not quite: mr. Gritz has several times (1)emphasized the importance of
analytical antialiasing (which requires surface derivatives) and POVMan
doesn't support it. Yet.

______________________________________
1)he wrote in c.g.r.r:
===8<=8<========
This is really the crux of the issue.  Writing a simple compiler
and interpreter is not all that hard.  Writing a renderer that
has all the internals to support the fancy(*) parts of Shading
Language is nontrivial.

(*) By fancy, I mean features that aren't used in "plastic" or any of
the 14 naive required shaders listed in the RI spec, but which are
*mandatory* for absolutely any real-world shader.  Among other things,
these would include: derivatives, area operators, named coordinate
systems, (automatically) filtered texture lookups, automatically
interpolated user vertex variables (for reference meshes and such),
illuminance loops to allow custom local illumination models, and
message passing between different shader types (especially between
lights and surfaces).
===8<=8<========
Sigh, long way is ahead: my patch currently supports illuminance loops.
Derivatives and filtered texture lookups hopefully sometime in future...
Message passing in limited extent is probably also possible...

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Hello!

I've updated my download page with new binary and source codes, which
should fix crashes during rerendering. Additionally, as it was noted,
bison gave error on grammar file and I've updated grammar file as well
for those, who want use bison.

As a bonus (for Your patience;-), I've created new examples page, which
contains one example (so far): cloud shader. Address is as follows:
http://www.aetec.ee/fv/vkhomep.nsf/pages/shdrex
It contains sample picture and source code for shader and POV-Ray scene.
It is product of some tinkering and therefore quality is not very good,
but if someone has time and wish to play with it, then this could be
used as starting point...
If I have more time, then I try to create some tutorial pages, which
show some commonly used techniques in shaders...

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Vahur Krouverk wrote:

> Warp wrote:
> >
> >   It would have been interesting if you had provided some benchmark results
> > (eg. how much time does it take to render a shader compared to a regular and
> > similar texture, etc).
> >
> Of course, but I've developed it on 486/DX2 66MHz and this is not just
> best box for benchmarks.
> Now when I have Windows version, I try to perform tests on my working
> machine (PII 350Mhz).
>
> But results of some tests (this was on performed on  Linux with debug
> version):
> Pure shader call (well, almost, it assigned red to surface color)
> increased execution time 33 % (pure POV-Ray executed scene 15 seconds,
> with shader it took time 20 seconds). Main overhead comes from memory
> management (separate shader instance is allocated each time in order to
> be reentrant), if I tried it without allocation, then time was almost
> same (16.xx sec). So there is area for improvement (one possibility it
> to preallocate shader instances).
> When shader has more code, then difference will be bigger: e.g. povshad
> scene, which renders one sphere with POV-Ray shading, other with shader
> language, has following results:
> Pure POV-Ray sphere: 12 seconds
> Shader sphere :      38 seconds
> Here probably illuminance loop, which is executed for shading, incurs
> such an overhead. Alas, this is the price for flexibility.
>
> However, I consider it as beta version and with this release I wanted to
> test, whether there is enough interest for such patch. So far I've tried
> to make it correct, performance has not been my major concern. In future
> I will tinker with performance buttons and knobs more.

Are you kidding? When I discovered that there exists something like POVMan, I
promptlly
went to its homepage. You can't imagine how I was disappointed when noticed there
is
no download available on the page! (Still I was lazy enough to mail the author :-)

I wonder whether the POV-Team consider implementing (any) shading language for the

planned 4.0 release. They say it's going to be a MAJOR rewrite of the POV-Ray
core.
Why not to expand POV's texturing and/or shading capabilities when such an
opportunity comes ?.

Thanks for your time spent on writing POVMan, you make a great job!


Jakub Hegenbart

heg### [at] postcz

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Jakub Hegenbart wrote:
>
> Are you kidding? 
What do You mean by kidding? Are You referring to my post, where wrote,
that I released this version for testing, whether there is interested
people for such patch? Well, I wrote this sentence seriously and
homepage statistics shows, that there is some interest, so I guess that
I'll start next version development.
Or did You mean something else? 

> When I discovered that there exists something like POVMan, I
> promptlly
> went to its homepage. You can't imagine how I was disappointed when noticed there
> is
> no download available on the page! (Still I was lazy enough to mail the author :-)
Are You talking about first version of POVMan, made by Bob Mercier? Or
is there problem with my version and You can't see downloads (there was
temporary problem couple of days ago, when I wanted to update page, but
due to my lack of experience with Lotus Notes/Domino it took some trials
to get it correctly done)?

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Vahur Krouverk wrote:

> ...homepage statistics shows, that there is some interest...

<Chuckle> that may be becuase I put a link to it on the povray.org
links pages :)

-- 
Ken Tyler - 1400+ POV-Ray, Graphics, 3D Rendering, and Raytracing Links:
http://home.pacbell.net/tylereng/index.html http://www.povray.org/links/

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Ken wrote:
> <Chuckle> that may be becuase I put a link to it on the povray.org
> links pages :)
Thanks, I know it, I've already made my egosurfing trip to this page ;-)

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Vahur Krouverk wrote:

> Jakub Hegenbart wrote:
> >
> > Are you kidding?
> What do You mean by kidding? Are You referring to my post, where wrote,
> that I released this version for testing, whether there is interested
> people for such patch? Well, I wrote this sentence seriously and
> homepage statistics shows, that there is some interest, so I guess that
> I'll start next version development.
> Or did You mean something else?

I thought it's obvious that I meant 'You don't have to ask, OF COURSE we're
interested,continue,pleeeeaaaasssseee!!!' :-)))

>
>
> > When I discovered that there exists something like POVMan, I
> > promptlly
> > went to its homepage. You can't imagine how I was disappointed when noticed there
> > is
> > no download available on the page! (Still I was lazy enough to mail the author :-)
> Are You talking about first version of POVMan, made by Bob Mercier? Or
> is there problem with my version and You can't see downloads (there was
> temporary problem couple of days ago, when I wanted to update page, but
> due to my lack of experience with Lotus Notes/Domino it took some trials
> to get it correctly done)?

You're right, I was talk...eh..writing about the Bob's version, Your page
is (more than) OK :)

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An errata: 'I thought it's obvious that I meant' should be "I thought it was obvious
that
I meant', of course. Excuse my English, I'm not an Englishman and thus I make mistakes
(Though not too often when it comes to consecutio temporum :)

Jakub Hegenbart wrote:

> Vahur Krouverk wrote:
>
> > Jakub Hegenbart wrote:
> > >
> > > Are you kidding?
> > What do You mean by kidding? Are You referring to my post, where wrote,
> > that I released this version for testing, whether there is interested
> > people for such patch? Well, I wrote this sentence seriously and
> > homepage statistics shows, that there is some interest, so I guess that
> > I'll start next version development.
> > Or did You mean something else?
>
> I thought it's obvious that I meant 'You don't have to ask, OF COURSE we're
> interested,continue,pleeeeaaaasssseee!!!' :-)))
>
> >
> >
> > > When I discovered that there exists something like POVMan, I
> > > promptlly
> > > went to its homepage. You can't imagine how I was disappointed when noticed
there
> > > is
> > > no download available on the page! (Still I was lazy enough to mail the author
:-)
> > Are You talking about first version of POVMan, made by Bob Mercier? Or
> > is there problem with my version and You can't see downloads (there was
> > temporary problem couple of days ago, when I wanted to update page, but
> > due to my lack of experience with Lotus Notes/Domino it took some trials
> > to get it correctly done)?
>
> You're right, I was talk...eh..writing about the Bob's version, Your page
> is (more than) OK :)

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