"Warp" <war### [at] tagpovrayorg> wrote...
>   I can't understand how it could "fade to black" if alpha channel would
not
> be taken into account when drawing the pixels.
>   This seems to work perfectly ok.

Interestingly enough, you BOTH are correct.

The antialiasing algorithm still blends the object with the background.
However, the new code compensates by adjusting weights to "unblend" the
color and blend the alpha channel instead.  Once the "unblending" is
complete, the antialiased pixels no longer contain any background color
information!  Only object information and alpha-channel blending remains.
The unblending & reblending is easiest if the background color is black
(otherwise we would have to somehow determine the raw BG color so we can
remove it).

The problem, as described earlier, is that "Colour_Distance" in colour.cpp
does not include the transparancy channels, and therefore a black object on
a black (clear) background will not be antialiased.

-Nathan

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