Ron Parker wrote:

> The spotlight isn't necessary to get this effect.  The problem, as I had
> suspected, is that the sampling interval for the point lights is essentially
> infinite, so the chance of getting a sample that scatters the light from the
> point sources is vanishingly small.  If you add a backstop like
> 
>  plane {-z,-500 pigment {rgbt 1}}
> 
> to the scene, it renders as expected (though it's all white.)  Notice the
> lack of the hollow keyword.  Since I didn't expect significant contributions
> from the media beyond 500 units, I elected to remove it from consideration and
> speed up the render a tad.  (indeed, if you add hollow it's still all white,
> as expected.)

The question that arises then is if this is desirable behavior. I expect
a point light to interact with media in a similar way as a spot light with
the exception that it is a uniform distribution of interaction rather than
a focused interaction like you recieve with a spotlight. To some degree
I understand why adding the plane works but wouldn't it be considered
a hack rather than desirable behavior ?

-- 
Ken Tyler -  1200+ Povray, Graphics, 3D Rendering, and Raytracing Links:
http://home.pacbell.net/tylereng/index.html http://www.povray.org/links/

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