"Ross" <rli### [at] everestkcnet> wrote:
> "Reynald" <rpa### [at] bluewinch> wrote in message
> news:web.42f35e1a3d56aaecf5f6f3660@news.povray.org...
> > Hi,
> > I'm playing around with light attenuation (fade_distance and fade_power)
> in
> > a container interior block. I noticed some behaviour that I don't
> > understand: the light source has to be positioned inside the fading
> > container for attenuation to occur. If the source is outside the container
> > then by rendering the effect of the beam on a screen we observe that
> > attenuation does not occur. If we activate Photons and add a scattering
> > media then we can verify this behaviour along the beam path from the
> source
> > up to the screen... same result, attenuation only occur when the source is
> > inside the container.
> >
> > I'm probably missing something?... or is it a well known feature of object
> > attenuation?
> >
> > Reynald
> >
> >
>
> the only thing i know of is this, from 3.3.7.9 of the docs:
>
> "Second, only light coming directly from light sources is attenuated.
> Reflected or refracted light is not attenuated by distance."

Yes to all of above.  Using photons (and then <GASP> radiosity on top) can
give VERY unexpected results.  Using the automatics when U have a
transparent/refractive object is a no-no in my book.  Decide how deep U want
to go,
and then set how many bounces manually.  You are VERY COOL- Keep it up and
re-read the docs that came with POV-Ray a thousand times!!!

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