clipka <ano### [at] anonymousorg> wrote:
> You mean something like this?
>
>      pigment { color red 0 green 1 blue 0 transmit 0.999 }
>      finish { diffuse 0 ambient 1000 }

No, and judging from that code sample, I've done a poor job of describing the
effect.

> If that doesn't do what you're thinking of, then a "full rgbtf vector"
> ambient wouldn't help you either.
>
> Also note that the construction you're thinking of would require special
> parsing of the parameter following the "ambient" keyword (or break
> compatibility): As of now, ambient *always* applies filter and transmit,
> but it's taken from the pigment, while what you want would be an
> independent filter and transmit parameter specifically for ambient. As
> from the parser's point of view, "rgb <1,1,1>" is perfectly equal to
> "rgbft <1,1,1,0,0>", this would conflict with the standard use case.

That doesn't sound good, but I made an image that shows more of what I had in
mind.  I posted it in p.b.i here:

http://news.povray.org/povray.binaries.images/thread/%3Cweb.4a7ca1d884f249fd4646012a0@news.povray.org%3E

 The way I understood things, the diffuse keyword controls the texture's amount
of response to light sources.  When checking to see whether or not an object is
lit, the surface normal is checked (to see if the object is facing the light
source).  From my understanding, if we thought of the normal direction as
compared to the light source as returning a percentage of illumination, then
the diffuse would multiplied by that percentage, and the ambient value would be
added (on an rgb component basis).  Assuming this is correct, I was wondering
whether or not the diffuse or ambient component could be full rgb vectors, and
have a filter and transmit value that is taken into account as well.  I'm
probably doing a mediocre job of describing an idea that is based on a poor
understanding of the lighting computations, so hopefully the image will clear
things up.

Anyway, I didn't mean to thread hijack - this started as a well intentioned
gripe about either limitations in controlling the way an object responds to
light, or my limitations in understanding how to control the way an object
responds to light.

-Reactor

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