On Fri, 16 Oct 1998 03:25:06 GMT, mr_### [at] hotmailcom (Benny
Sanjaya) wrote:

>Why This nice raytracing doesn't support SHADERS plugins... ?
>Please make povray able to use BMRT SHADERS :) in the future :)
>
>people PLEASE support me :)

Why should we support you if you can't have the common decency to pick
one or two relevant groups and limit your crossposts?

That said, there was a patch for POV 2.2 that purported to support at
least part of the Renderman Shading Language, though attempts to port
it to 3.0 were unsuccessful, to say the least.

There are a couple of major stumbling blocks to a successful
implementation of RSL, not the least of which is the problem of POV
not having access to some of the special variables that are considered
standard in a shader.  For example, there are u, v, du, dv, dPdu,
dPdv...  These are all meaningless when POV doesn't have u-v texture
mapping.

Post a reply to this message

par### [at] mailfwicom (Ronald L. Parker) wrote:

>On Fri, 16 Oct 1998 03:25:06 GMT, mr_### [at] hotmailcom (Benny
>Sanjaya) wrote:
>
>>Why This nice raytracing doesn't support SHADERS plugins... ?
>>Please make povray able to use BMRT SHADERS :) in the future :)
>>
>>people PLEASE support me :)
>
>Why should we support you if you can't have the common decency to pick
>one or two relevant groups and limit your crossposts?

Exactly my opinion. Excessive cross-posting is a PITA and is one of the few
things that will get an article on this server deleted (as I just did to his
original post).

Post a reply to this message

povray.org admin team wrote:

> >>Why This nice raytracing doesn't support SHADERS plugins... ?
> >>Please make povray able to use BMRT SHADERS :) in the future :)
> >>
> >>people PLEASE support me :)

> ...Excessive cross-posting is a PITA and is one of the few
> things that will get an article on this server deleted...

EXCESSIVE smiley faces :):):) and CAPITALIZATION :):) are HOPEFULLY
some of the others :):):).

Post a reply to this message

"Ronald L. Parker" wrote:

> That said, there was a patch for POV 2.2 that purported to support at
> least part of the Renderman Shading Language, though attempts to port
> it to 3.0 were unsuccessful, to say the least.
> 
> There are a couple of major stumbling blocks to a successful
> implementation of RSL, not the least of which is the problem of POV
> not having access to some of the special variables that are considered
> standard in a shader.  For example, there are u, v, du, dv, dPdu,
> dPdv...  These are all meaningless when POV doesn't have u-v texture
> mapping.

Has this situation changed with the addition of UV mapping to MegaPov ?


I announced the existence of the POV-Ray Tag on the IRTC mailing list
yesterday and within 2 hrs. got a request for programmable shaders :)

-- 
Ken Tyler -  1300+ Povray, Graphics, 3D Rendering, and Raytracing Links:
http://home.pacbell.net/tylereng/index.html http://www.povray.org/links/

Post a reply to this message

"Ken" <tyl### [at] pacbellnet> wrote :
>
> I announced the existence of the POV-Ray Tag on the IRTC mailing list
> yesterday and within 2 hrs. got a request for programmable shaders :)
>

    I had the immediate suspicion that Jonathan Merritt was an
unregisterable copy of KenAI ver 0.01a running on a 8088 with a 300 baud
modem.

    see... this would explain the two hour delay... get it?  ...because it
was a old program on a slo... and the modem was... Oh! Never mind!

    Why am I the only one who likes my jokes 8-(

Post a reply to this message

Bill DeWitt wrote:

>     Why am I the only one who likes my jokes 8-(

Some people are good story tellers. Others are, well you get the picture...

-- 
Ken Tyler -  1300+ Povray, Graphics, 3D Rendering, and Raytracing Links:
http://home.pacbell.net/tylereng/index.html http://www.povray.org/links/

Post a reply to this message

On Sat, 22 Jan 2000 05:02:32 -0800, Ken wrote:
>
>
>"Ronald L. Parker" wrote:
>
>> That said, there was a patch for POV 2.2 that purported to support at
>> least part of the Renderman Shading Language, though attempts to port
>> it to 3.0 were unsuccessful, to say the least.
>> 
>> There are a couple of major stumbling blocks to a successful
>> implementation of RSL, not the least of which is the problem of POV
>> not having access to some of the special variables that are considered
>> standard in a shader.  For example, there are u, v, du, dv, dPdu,
>> dPdv...  These are all meaningless when POV doesn't have u-v texture
>> mapping.
>
>Has this situation changed with the addition of UV mapping to MegaPov ?

To some extent, but not entirely.  If UV mapping applied to all objects,
it would be a good start.  But we still need du, dv, dPdu, dPdv, etc.
which we can probably best get by implementing differential tracing.
Don't worry, the POV-Team isn't ignoring the requests to make shading 
more powerful for some future version (not 3.5!) but the final result 
might not be RSL.  Don't ask for more informationon this, as more 
information does not exist.

-- 
The superpatch: http://www2.fwi.com/~parkerr/superpatch/
My other stuff: http://www2.fwi.com/~parkerr/traces.html

Post a reply to this message

Ron Parker wrote:

> >Has this situation changed with the addition of UV mapping to MegaPov ?
> 
> To some extent, but not entirely.  If UV mapping applied to all objects,
> it would be a good start.  But we still need du, dv, dPdu, dPdv, etc.
> which we can probably best get by implementing differential tracing.
> Don't worry, the POV-Team isn't ignoring the requests to make shading
> more powerful for some future version (not 3.5!) but the final result
> might not be RSL.

I already replied there was not much if any chance of it making it into
v3.5 and only a possibility for 4.0. I did mention that if anyone would
like to patch POV-Ray with this feature that the POV-Team would be happy
to evaluate it :)

>  Don't ask for more informationon this, as more information does not exist.

I am happy with your reply.

-- 
Ken Tyler -  1300+ Povray, Graphics, 3D Rendering, and Raytracing Links:
http://home.pacbell.net/tylereng/index.html http://www.povray.org/links/

Post a reply to this message

"Ken" <tyl### [at] pacbellnet> wrote :
>
> Some people are good story tellers. Others are, well you get the
picture...
>

    Hmm... I can't figure out what you mean by this....

Post a reply to this message

Bill DeWitt wrote in message <3889b808@news.povray.org>...
>    Why am I the only one who likes my jokes 8-(
regrettably I must confess to enjoying you jokes.
That 'r' shoud be in CAPS.

someone who has no place with Parker, DeWitt and Tyler.

Post a reply to this message

Sounds like a law firm or something.

Peter Warren wrote:
>Parker, DeWitt and Tyler.<

-- 
Mr. Art

"Often the appearance of reality is more important 
than the reality of the appearance."
Bill DeWitt 2000

Post a reply to this message

Ken wrote:
>"Ronald L. Parker" wrote:
>
>> That said, there was a patch for POV 2.2 that purported to support at
>> least part of the Renderman Shading Language,..
>
>I announced the existence of the POV-Ray Tag on the IRTC mailing list
>yesterday and within 2 hrs. got a request for programmable shaders :)

What are programmable shaders?
Can sombody try explain this to me in laymens terms, or point me to a page 
that does so. I did a (very) quick search this morning but found only stuff 
that needs at least a basic understanding of shaders. And that I do not 
have.


Ingo

-- 
Photography: http://members.home.nl/ingoogni/
Pov-Ray    : http://members.home.nl/seed7/

Post a reply to this message

mr.art wrote in message <3889FAE3.CA30DBBD@gci.net>...
>Sounds like a law firm or something.
>
>Peter Warren wrote:
>>Parker, DeWitt and Tyler.<

I miss spoke.

That  would be
"Xander, Parker, DeWitt and Tyler"

So sue me, I'm an idiot.

No refection.

Post a reply to this message

your

Post a reply to this message

"Peter Warren" <int### [at] halcyoncom> wrote :
>
> someone who has no place with Parker, DeWitt and Tyler.
>

    I hope you are talking about posting frequency, or something like that.
Because if you are talking about POV skills, I have to tell you that I do
not have half the skills of Ken. And I am fairly confident that Ken will
tell you that he doesn't have half the skills of Ron.

    If you can rub two mirrored spheres together you have caught up with
me...

Post a reply to this message

I would welcome shaders.

I also hope they do not happen, at least for a while.


Peter (Oh, what a wimp)Warren

Post a reply to this message

Bill DeWitt wrote in message <388a12b7@news.povray.org>...

>    I hope you are talking about posting frequency, or something like that.
>Because if you are talking about POV skills, I have to tell you that I do
>not have half the skills of Ken. And I am fairly confident that Ken will
>tell you that he doesn't have half the skills of Ron.

>    If you can rub two mirrored spheres together you have caught up with
>me...

I am fairly confident that Ken would tell you that he does not
have 1/10th the skills of Ron. (And then he would be boasting).

I also believe that if you rubbed two mirrored spheres
together you would produce an interesting image.
More interesting than the one I would produce, no doubt.

I know that you have made me laugh, more than once,
more than twice.

For this I thank and respect you.

I can say no more.

Peter Warren

Post a reply to this message

Am I right if I say :
The required skills to program a shader are almost equal to
the skills required to program a new texture/pattern into the
core Povray code ?

After all, and if I understood well, renderman shaders must
be compiled with an ordinary C++ compiler, and they are -sort of-
dynamically linked to the renderer (who gives some data to
the shader, and get a pixel color or some other data in return).

About UV-stuff, the renderers that have shaders usually have only
a few types of primitives : nurbs, bicubic things,...  And we know
that some Pov privitives CAN'T be UV-mapped : julias,...

Fabien.

Post a reply to this message

On Sat, 22 Jan 2000 15:27:34 -0500, Bill DeWitt wrote:
>
>"Peter Warren" <int### [at] halcyoncom> wrote :
>>
>> someone who has no place with Parker, DeWitt and Tyler.
>>
>
>    I hope you are talking about posting frequency, or something like that.
>Because if you are talking about POV skills, I have to tell you that I do
>not have half the skills of Ken. And I am fairly confident that Ken will
>tell you that he doesn't have half the skills of Ron.

And I don't have half the skills of Gilles Tran or SamuelT or Mick
Hazelgrove.  It's all relative.

-- 
These are my opinions.  I do NOT speak for the POV-Team.
The superpatch: http://www2.fwi.com/~parkerr/superpatch/
My other stuff: http://www2.fwi.com/~parkerr/traces.html

Post a reply to this message

On Sat, 22 Jan 2000 22:30:59 +0100, Fabien Mosen wrote:
>Am I right if I say :
>The required skills to program a shader are almost equal to
>the skills required to program a new texture/pattern into the
>core Povray code ?

Pretty much, yeah.  Maybe more, if the trend goes toward self-
antialiasing shaders a'la those that Larry Gritz has made.

>After all, and if I understood well, renderman shaders must
>be compiled with an ordinary C++ compiler, and they are -sort of-
>dynamically linked to the renderer (who gives some data to
>the shader, and get a pixel color or some other data in return).

Not exactly.  They're compiled into bytecode (IIRC) by the shader
compiler, which is not really a C compiler.  They're then executed
by the renderer pretty much as you say.

>About UV-stuff, the renderers that have shaders usually have only
>a few types of primitives : nurbs, bicubic things,...  And we know
>that some Pov privitives CAN'T be UV-mapped : julias,...

Right.  RIB only allows for a small subset of objects with easy UV
mappings.  But even some of those objects don't have UV code written
yet in MegaPOV.  One could always warn that a shader that expected
uv coordinates wouldn't work properly on a non-UV-enabled object.

-- 
These are my opinions.  I do NOT speak for the POV-Team.
The superpatch: http://www2.fwi.com/~parkerr/superpatch/
My other stuff: http://www2.fwi.com/~parkerr/traces.html

Post a reply to this message

What about me? :)

>>And I don't have half the skills of Gilles Tran or SamuelT or Mick
>>Hazelgrove.  It's all relative.

I am, of course, joking.

--
H.E. Day
------------------------
Science is merely a method of gathering data and information.
Science *cannot* prove facts.
It can only provide theories that fit given data.
Technology is merely Science applied to common situations.
Technology is used for both good and evil.
Society is a framework mostly dependent on the willing participation of it
subjects.
Kingdoms and dominions come and go, none are eternal.
In the end, Society, Technology, and Science do not matter.  Only the actions
and choices of the individual will matter. <><

Post a reply to this message

Ron Parker wrote:

> > And I am fairly confident that Ken will tell you that he doesn't
> > have half the skills of Ron.
> 
> And I don't have half the skills of Gilles Tran or SamuelT or Mick
> Hazelgrove.  It's all relative.

I'm starting to sound like a rank amateur. Gee thanks guy's !

< pout > < sniff >

-- 
Ken Tyler -  1300+ Povray, Graphics, 3D Rendering, and Raytracing Links:
http://home.pacbell.net/tylereng/index.html http://www.povray.org/links/

Post a reply to this message

Amateur: one that loves what they do. 
Rank: part of the "Rank and File", the common folk.
I hope that you are an Amateur. You will never be rank.

Ken wrote:
> 
> Ron Parker wrote:
> 
> > > And I am fairly confident that Ken will tell you that he doesn't
> > > have half the skills of Ron.
> >
> > And I don't have half the skills of Gilles Tran or SamuelT or Mick
> > Hazelgrove.  It's all relative.
> 
> I'm starting to sound like a rank amateur. Gee thanks guy's !
> 
> < pout > < sniff >
> 
> --
> Ken Tyler -  1300+ Povray, Graphics, 3D Rendering, and Raytracing Links:
> http://home.pacbell.net/tylereng/index.html http://www.povray.org/links/

-- 
Mr. Art

"Often the appearance of reality is more important 
than the reality of the appearance."
Bill DeWitt 2000

Post a reply to this message

On Sat, 22 Jan 2000 16:24:16 -0900, mr.art wrote:
>Amateur: one that loves what they do. 
>Rank: part of the "Rank and File", the common folk.
>I hope that you are an Amateur. You will never be rank.

I dunno, skip enough showers and anything could happen...

Post a reply to this message

On Sat, 22 Jan 2000 17:06:57 -0800, Ken wrote:
>
>
>Ron Parker wrote:
>
>> > And I am fairly confident that Ken will tell you that he doesn't
>> > have half the skills of Ron.
>> 
>> And I don't have half the skills of Gilles Tran or SamuelT or Mick
>> Hazelgrove.  It's all relative.
>
>I'm starting to sound like a rank amateur. Gee thanks guy's !

Well, if you did say you weren't half as skilled as I, I'd have to
take issue with it.  I'm not that good at actually USING the stuff.

-- 
These are my opinions.  I do NOT speak for the POV-Team.
The superpatch: http://www2.fwi.com/~parkerr/superpatch/
My other stuff: http://www2.fwi.com/~parkerr/traces.html

Post a reply to this message

Ron Parker wrote:

> >> And I don't have half the skills of Gilles Tran or SamuelT or Mick
> >> Hazelgrove.  It's all relative.
> >
> >I'm starting to sound like a rank amateur. Gee thanks guy's !
> 
> Well, if you did say you weren't half as skilled as I, I'd have to
> take issue with it.  I'm not that good at actually USING the stuff.

I really think I could give you, Samual, and Mick a run for your money
if I set my mind to it but Gilles I couldn't touch if I tried.

-- 
Ken Tyler -  1300+ Povray, Graphics, 3D Rendering, and Raytracing Links:
http://home.pacbell.net/tylereng/index.html http://www.povray.org/links/

Post a reply to this message

On Sat, 22 Jan 2000 19:13:16 -0800, Ken wrote:
>I really think I could give you, Samual, and Mick a run for your money
>if I set my mind to it but Gilles I couldn't touch if I tried.

Ooh, that sounds like a challenge.  Like our own little IRTC. :)

-- 
These are my opinions.  I do NOT speak for the POV-Team.
The superpatch: http://www2.fwi.com/~parkerr/superpatch/
My other stuff: http://www2.fwi.com/~parkerr/traces.html

Post a reply to this message

Ron Parker wrote:
> 
> On Sat, 22 Jan 2000 19:13:16 -0800, Ken wrote:
> >I really think I could give you, Samual, and Mick a run for your money
> >if I set my mind to it but Gilles I couldn't touch if I tried.
> 
> Ooh, that sounds like a challenge.  Like our own little IRTC. :)

Sounds like fun. The topic will be "Printed Circuit Board Plating Facility".

<BG>

-- 
Ken Tyler -  1300+ Povray, Graphics, 3D Rendering, and Raytracing Links:
http://home.pacbell.net/tylereng/index.html http://www.povray.org/links/

Post a reply to this message

Ken wrote in message <388A7ACD.28CFFA41@pacbell.net>...
>Sounds like fun. The topic will be "Printed Circuit Board Plating
Facility".


O.T. but,
There is an artist, Peter Halley
[American Minimalist Painter, Born 1953]
who bases some of his work on the circuit board.

Peter

Post a reply to this message

Peter Warren wrote:
> 
> Ken wrote in message <388A7ACD.28CFFA41@pacbell.net>...
> >Sounds like fun. The topic will be "Printed Circuit Board Plating
> Facility".
> 
> O.T. but,
> There is an artist, Peter Halley
> [American Minimalist Painter, Born 1953]
> who bases some of his work on the circuit board.

I find don't this totaly surprising yet I wonder at his intentions.

-- 
Ken Tyler -  1300+ Povray, Graphics, 3D Rendering, and Raytracing Links:
http://home.pacbell.net/tylereng/index.html http://www.povray.org/links/

Post a reply to this message

Ken wrote in message <388AF2E5.A0ABADB3@pacbell.net>...
>I find don't this totaly surprising yet I wonder at his intentions.


Hum, I don't think I get your drift here.

Do you mean: "Why would someone spend 20 years
of his life basically painting the same painting over
and over again?"
Or, as a pretty much Blue Chip artist do you mean:
"Is he only in it for the money?"

Or...

Peter Warren
war### [at] hotmailcom

Post a reply to this message

Peter Warren wrote:
> 
> Ken wrote in message <388AF2E5.A0ABADB3@pacbell.net>...
> >I find don't this totaly surprising yet I wonder at his intentions.
> 
> Hum, I don't think I get your drift here.
> 
> Do you mean: "Why would someone spend 20 years
> of his life basically painting the same painting over
> and over again?"
> Or, as a pretty much Blue Chip artist do you mean:
> "Is he only in it for the money?"
> 
> Or...

No, I meant why paint circuit boards.

-- 
Ken Tyler -  1300+ Povray, Graphics, 3D Rendering, and Raytracing Links:
http://home.pacbell.net/tylereng/index.html http://www.povray.org/links/

Post a reply to this message

Ken wrote:

> No, I meant why paint circuit boards.

Never mind. I think I found the answer. The guy is a nut case.

http://members.aol.com/MenuBar/abstract/halley.htm

-- 
Ken Tyler -  1300+ Povray, Graphics, 3D Rendering, and Raytracing Links:
http://home.pacbell.net/tylereng/index.html http://www.povray.org/links/

Post a reply to this message

Ken <tyl### [at] pacbellnet> wrote in message news:388A7ACD.28CFFA41@pacbell.net...
>
> Sounds like fun. The topic will be "Printed Circuit Board Plating Facility".
>

<scene>China developing dish as used by photographers, full of brown soup - that's the
electrolyte, but you can't see my PC coz of the murk.</scene>

Alf

http://www.peake42.freeserve.co.uk
http://ourworld.compuserve.com/homepages/Alf_Peake/

Post a reply to this message

Ken wrote:
> 
> Ron Parker wrote:
> 
> > > And I am fairly confident that Ken will tell you that he doesn't
> > > have half the skills of Ron.
> >
> > And I don't have half the skills of Gilles Tran or SamuelT or Mick
> > Hazelgrove.  It's all relative.
> 
> I'm starting to sound like a rank amateur. Gee thanks guy's !
> 
> < pout > < sniff >

I know a lot of SCA calligraphers who show their work to each other, and
everybody complains, "Why is your stuff so beautiful when mine sucks?"
EVERYONE says it!

Except for the egotistical, black-turtleneck-and-beret-wearing,
clove-cigarette-smoking, espresso-drinking goateed beatnik wannabe's
(present company excluded ;-), most artists are convinced of their own
inferiority at art.  This has mostly to do with the fact that you are
all to familiar with every last flaw in your own work (after all, you
spent hours working on it), but most people (including other artists)
won't be nearly so cognisant of your failings.  Hence, you are your own
worst critic.

-Mark Gordon

Post a reply to this message

ingo wrote:

> What are programmable shaders?
> Can sombody try explain this to me in laymens terms, or point me to a page
> that does so. I did a (very) quick search this morning but found only stuff
> that needs at least a basic understanding of shaders. And that I do not
> have.

Basically, shaders are functions written in the RenderMan Shading
Language
(a language that on first inspection looks very similar to C) that
explicitly describe the interaction between light and some element of
the scene being rendered. For instance, there are surface shaders (which
return the color of light reflected from a point on a surface),
displacement shaders (which allow the surface of a solid to be modified
in some algorithmic manner, such as regularly-spaced dimples or bumps),
volume shaders (which modify the characteristic of light passing through
a volume of space, the interior of an object, et cetera), and others.
Their power comes from the fact that shaders allow the artist to
describe
*exactly* how the light interacts with a surface, how light is generated
by a light source (light source shaders), how a surface interacts with
reflected light (by calculating intensity, direction, color of reflected
light), and so forth. The interaction need not even be realistic; you
have
total freedom in your calculations.

There is a rather significant learning curve involved in using shaders.
I'd recommend "The RenderMan Companion" by Steve Upstill as a start.
It's ten years old, but it's still considered the classic beginner's
text on RenderMan, and it gives a good overall view about what shaders
do.

Post a reply to this message

Ken wrote:

> Ron Parker wrote:
> >
> > On Sat, 22 Jan 2000 19:13:16 -0800, Ken wrote:
> > >I really think I could give you, Samual, and Mick a run for your money
> > >if I set my mind to it but Gilles I couldn't touch if I tried.
> >
> > Ooh, that sounds like a challenge.  Like our own little IRTC. :)
>
> Sounds like fun. The topic will be "Printed Circuit Board Plating Facility".

What's all this? If that is the challenge, I've already lost!

--
Samuel Benge

E-Mail: STB### [at] aolcom

Visit the still unfinished isosurface tutorial: http://members.aol.com/stbenge

Post a reply to this message

"SamuelT." wrote:

> > Sounds like fun. The topic will be "Printed Circuit Board Plating Facility".
> 
> What's all this? If that is the challenge, I've already lost!

It was a joke son.

I picked a topic that I know that I am intimately familiar with and no
one else would be.  Gives me that winning edge.

If the topic were "A Scene Developed with only Matematical Constructs"
I would likewise be at a severe dissadvantage.

If the topic were "Poser figures in Pov" Gilles and Mick would have the
advantage because they own a copy of Poser and I don't.

-- 
Ken Tyler -  1300+ Povray, Graphics, 3D Rendering, and Raytracing Links:
http://home.pacbell.net/tylereng/index.html http://www.povray.org/links/

Post a reply to this message

Ken wrote:

> Sounds like fun. The topic will be "Printed Circuit Board Plating Facility".
>

Count me in. Look at what I did with printed circuit boards...
http://www.synaptic.ch/Greve/gtran/tran.htm
http://www.synaptic.ch/Greve/gtran/tran2.htm
(these pages need Flash)
These objects were made for a collective "installation" 2 years ago.
I didn't know these things were so hard to break and tear apart (got a few
blisters after that)...

G.

Post a reply to this message

Gilles Tran wrote:
> 
> Ken wrote:
> 
> > Sounds like fun. The topic will be "Printed Circuit Board Plating Facility".
> >
> 
> Count me in. Look at what I did with printed circuit boards...
> http://www.synaptic.ch/Greve/gtran/tran.htm
> http://www.synaptic.ch/Greve/gtran/tran2.htm
> (these pages need Flash)
> These objects were made for a collective "installation" 2 years ago.

They are different :)

> I didn't know these things were so hard to break and tear apart (got a few
> blisters after that)...

Tougher than most people would give them credit for. We use high
speed routers with tungsten carbide router bits to fabricate them
with.

-- 
Ken Tyler -  1300+ Povray, Graphics, 3D Rendering, and Raytracing Links:
http://home.pacbell.net/tylereng/index.html http://www.povray.org/links/

Post a reply to this message

I really liked those, I checked them out a while ago and thought "gee I
wouldn't mind a few of those around here"

--
Lance.
The Zone - http://come.to/the.zone
Gilles Tran <tra### [at] inapginrafr> wrote in message
news:388C433F.B3A73851@inapg.inra.fr...
>
> Ken wrote:
>
> > Sounds like fun. The topic will be "Printed Circuit Board Plating
Facility".
> >
>
> Count me in. Look at what I did with printed circuit boards...
> http://www.synaptic.ch/Greve/gtran/tran.htm
> http://www.synaptic.ch/Greve/gtran/tran2.htm
> (these pages need Flash)
> These objects were made for a collective "installation" 2 years ago.
> I didn't know these things were so hard to break and tear apart (got a few
> blisters after that)...
>
> G.
>

Post a reply to this message

Ken wrote:
> 
> Has this situation changed with the addition of UV mapping to MegaPov ?
> 
> I announced the existence of the POV-Ray Tag on the IRTC mailing list
> yesterday and within 2 hrs. got a request for programmable shaders :)
> 
> --

Sorry for late reply, but I was for a week on the mountains and off from
civilization (i.e. internet). 

I'm currently working with Shader patch, which is based on Mercier's
POVMAN patch. I wrote letter to  mr. Mercier and got his permission to
use his work as suitable. So far I got his initial version integrated
with MegaPov and some example shaders working. Currently I'm working
with shader compiler, for POVMAN version was rather limited.(this was
initially going rather slowly due to my inexperience with LEXX and YACC,
but now I've got grip). I try to add as much support for RM SL version
3.8 as possible: so far I've added support for vector and normal
keywords, support for mixing of variable declarations and statements).
After that I was able to compile wood shader from BMRT distribution and
its rendering even resembled wood ;-) 
My next task is adding support for user defined functions, as quite a
number of shaders use them. Then will come (???) matrixes and arrays.

One important thing is to add support for uv stuff, hopefully when I get
so far, someone will help me, as I don't have experience with it. 

Some of RM features will probably never be implemented, e.g. message
passing. My intention is to make easier creation of new patterns or
extending old ones, all this without source code compilation (e.g. it
would be quite easy to create slope dependent pattern with this patch).
If one is lucky, then it could be possible to use other features of RM
SL as well, but generally it ain't that easy. I guess that best would
be, if unimplemented features produce warning and will be eaten up by
shading compiler.

Well, I hope that all of you, who want shaders, do not get expectations
too high, as I don't have mucho tiempo for my patching (worst of all,
during new year holidays I managed to delete my files and had to start
from scratch). But I'm intended to work on it until it gives some
results or it is clear, that I'm not able to do it...

P.S. I'd like to see, that in this group (and other groups as well, save
p.o-t) messages are more on-topic.

Post a reply to this message

Ron Parker wrote:

> >After all, and if I understood well, renderman shaders must
> >be compiled with an ordinary C++ compiler, and they are -sort of-
> >dynamically linked to the renderer (who gives some data to
> >the shader, and get a pixel color or some other data in return).
> 
> Not exactly.  They're compiled into bytecode (IIRC) by the shader
> compiler, which is not really a C compiler.  They're then executed
> by the renderer pretty much as you say.
> 
Adjustment:
IIRC new version of BMRT shader compiler (2.5???) will compile shader
into C code, and RenderDotC  (another RM compliant scanline renderer)
compiles as well shader into C code, from which shared library (or dll)
is created.

Post a reply to this message

Oh, I forgot:
All my previous message was about surface (one can say pigment/texture)
shader. Is there interest in displacement shader? If there is, then I
would appreciate links/hints, how this should be implemented (in
unofficial.patches perhaps).

Post a reply to this message

Vahur Krouverk wrote:
> 
> Oh, I forgot:
> All my previous message was about surface (one can say pigment/texture)
> shader. Is there interest in displacement shader? If there is, then I
> would appreciate links/hints, how this should be implemented (in
> unofficial.patches perhaps).

I am glad to here that someone is working on it even if it is a basic
implementation. While you are working on it and you need advice I
suggest you take your questions to the povray.programming group. The
unofficial.patches group is more for when you actually have a working
model and you need feedback on it from people trying it out for you.
Right now you need programming specific issues resolved and .programming
is ideal for this purpose.

Cheers and good luck,

-- 
Ken Tyler -  1300+ Povray, Graphics, 3D Rendering, and Raytracing Links:
http://home.pacbell.net/tylereng/index.html http://www.povray.org/links/

Post a reply to this message