On Tue, 27 Mar 2001 10:36:14 -0700, Ryan Mooney wrote:
>Ok let me be more clear here is the code for the two planes... the bottom one
>has no reflection and is copying the top one exactly... why...??

Because planes don't do what you think they do.

Your camera is inside of the plane with media.  When the ray exits that
plane (the top half of the picture) POV calculates media effects along the
length of the ray, giving you the media effects you see in the top half
of the picture.  When the ray enters a solid object (the other plane, on
the bottom half of the picture) POV also calculates media effects along
the length of the ray, giving you the effects you see in the bottom half.
If the ray never hits anything, POV never calculates the media effects, 
and you get the black line you see between the planes.

All of the media you're seeing is between the camera and one plane or the
other.  It is not on the other side of either plane.  If you invert the 
top plane, the media will be on the other side of it, but you will notice
that your media effects disappear entirely in that case, as the ray never
exits the top plane after having entered it and thus the effects are never
calculated.

In general, using infinite objects as media containers is not a good idea.
This scene can be made to work, but only from some camera positions and 
angles.

-- 
Ron Parker   http://www2.fwi.com/~parkerr/traces.html
My opinions.  Mine.  Not anyone else's.

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