In article <3A663311.4A4A8FE1@faricy.net>, David Fontaine 
<dav### [at] faricynet> wrote:

> POVMan is a POV/Renderman hybrod or such IIRC.

It is an unofficial version of POV-Ray which supports RenderMan-like 
shaders.


> I'm going to venture a guess on shaders, but I don't actually know: does
> it let you specify a falloff_map of sorts, like a color_map or slope_map
> except related to brilliance and angle of incidence? I'm guessing
> because I notice hue changes perpendicular to the light direction in
> these renders.

Shaders are just bits of code that specify how the color of the surface 
is calculated. POVMan shaders are written in a special language that is 
different than POV-Script and based on the RenderMan lanugage, it is 
basically a way to customize rendering without having to patch the 
program. The shaders are interpreted, so there is a speed penalty for 
this flexibility. And I think POVMan shaders are just special pigments, 
so you should be able to combine them with ordinary finish and normal 
features, but would normally use ambient 1 to get the unmodified result 
of the shader.
Basically super-functions which can handle colors and vectors and have a 
different set of built-in functions, and result in a color instead of an 
index for a color_map.

-- 
Christopher James Huff
Personal: chr### [at] maccom, http://homepage.mac.com/chrishuff/
TAG: chr### [at] tagpovrayorg, http://tag.povray.org/

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Chris Huff wrote:

> > I'm going to venture a guess on shaders, but I don't actually know: does
> > it let you specify a falloff_map of sorts, like a color_map or slope_map
> > except related to brilliance and angle of incidence? I'm guessing
> > because I notice hue changes perpendicular to the light direction in
> > these renders.
>
> Shaders are just bits of code that specify how the color of the surface
> is calculated. POVMan shaders are written in a special language that is
> different than POV-Script and based on the RenderMan lanugage, it is
> basically a way to customize rendering without having to patch the
> program. The shaders are interpreted, so there is a speed penalty for
> this flexibility. And I think POVMan shaders are just special pigments,
> so you should be able to combine them with ordinary finish and normal
> features, but would normally use ambient 1 to get the unmodified result
> of the shader.
> Basically super-functions which can handle colors and vectors and have a
> different set of built-in functions, and result in a color instead of an
> index for a color_map.

So in a way I was right... :)

--
David Fontaine  <dav### [at] faricynet>  ICQ 55354965
My raytracing gallery:  http://davidf.faricy.net/

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In article <3A6667DC.D7C2FF34@faricy.net>, David Fontaine 
<dav### [at] faricynet> wrote:

> So in a way I was right... :)

Sort of...there is no "falloff_map" and it doesn't use a color_map, but 
it lets you do all those things. (As well as nearly any other effect 
that can be programmed.)

-- 
Christopher James Huff
Personal: chr### [at] maccom, http://homepage.mac.com/chrishuff/
TAG: chr### [at] tagpovrayorg, http://tag.povray.org/

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Chris Huff wrote:

> > So in a way I was right... :)
>
> Sort of...there is no "falloff_map" and it doesn't use a color_map, but
> it lets you do all those things. (As well as nearly any other effect
> that can be programmed.)

I did make it a simile. :P

--
David Fontaine  <dav### [at] faricynet>  ICQ 55354965
My raytracing gallery:  http://davidf.faricy.net/

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In article <3A68CD06.44366D19@faricy.net>, David Fontaine 
<dav### [at] faricynet> wrote:

> I did make it a simile. :P

Well, I *did* fail the second half of Grammar III last year... ;-)

-- 
Christopher James Huff
Personal: chr### [at] maccom, http://homepage.mac.com/chrishuff/
TAG: chr### [at] tagpovrayorg, http://tag.povray.org/

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