"Don Barron" <ani### [at] ukonlinecouk> wrote in message
news:web.3e458a2e68f85955299143b00@news.povray.org...
> Dear Mr.Hughes,
>
> Rereading the missages I see that I have incorrectly attributed to SLIME
> himself  the pov file elaborating SLIME's suggestion concerning a solution
> to the question.  Please accept my apologies - and I hope you enjoyed my
> modest extension to your elegant solution.
>
> I find it strange that the messages are printed in reverse order - I
expect
> to see the latest at the top of the list...anyway, thanks again.

And Mr. Barron... or Don if I may, I wasn't going to mention it. Doesn't
matter to me. It started off as yours and his ideas anyhow. Tor also led me
in the right direction.

I went looking a tiny bit further into this and now I'm confused why I
managed to get the correct result by putting radians() inside the cos(). I
only made it through Algebra III in school, which doesn't help me here.
POV-Ray supposedly does the cosine in radians already, so when I first tried
degrees() and didn't get the right answer that made me think I was doing it
all wrong. Using it outside of cos() is of no use either, apparently. Maybe
acos() is okay, as Tor suggested but I never tried that. So I'm puzzled as
to how the radians of a float is acted upon by the cos() function.

Well, that aside, I tried what you changed it all too so I could see what
you were making of it. Seems to me there needs to be a way to cause the
fall-off to--- well, fall off at a certain rate dependant on the amount of
angle as it changes through the color map. Of course, I noticed you said you
weren't trying for the actual fall off of light per the cos 4th law but
instead wanting to mimic some kind of vignetting due to obstruction that is
part of a lens. At least I think you said that.

If anybody thinks cos(radians()) = degrees is peculiar I'm all ears. I'll
have learned something.

--
Farewell,
Bob

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