"Edward C." wrote:
> 
> >You can't really call call it a bug in the official version because it is
> >documented.
> 
> Can you point me to where it is documented?  I've looked, but cannot find it
> anywhere.

Actually, I think you may be right.  I just checked the documentation, and
it says (under Layered Textures):
"The color of underlying layers is filtered by upper layers but the results do
not look exactly like a series of transparent surfaces. If you had a stack of
surfaces with the textures applied to each, the light would be filtered twice:
once on the way in as the lower layers are illuminated by filtered light and
once on the way out. Layered textures do not filter the illumination on the way
in. Other parts of the lighting calculations work differently as well. The
results look great and allow for fantastic looking textures but they are simply
different from multiple surfaces. See stones.inc in the standard include files
directory for some magnificent layered textures."

Notice that it does say "filtered", not "transmitted".  So there is a
difference between what the docs say and what the program does.

I personally think that this should be 'fixed' in POV 4.0 so that it does
work 'correctly'.  Yes, this will break scenes, but not to the extent that
most people would expect.  The fact that POV treats filter like transmit
right now means that users are probably not mixing little bits of filter
and transmit, at least not with layered textures (and layered textures is
the only thing affected).  So, people probably used either filter or
transmit and never noticed that they looked te same.  Or if they used
both they add together.

So rgbft<1,1,1,1,1> would turn into rgbt<1,1,1,2> with the new system (add
the filter and transmit)... but only in a layer, of course. Now, I'm not
sure if UVPov currently allows transmit over 1.0 (I think it does), but
some official standard that makes sense could be adopted.

-Nathan

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