I did not intend to raise such a hornet's nest here (maybe I did). But the
debate is fascinated and it was great to see such life in the forum. It's been
*enlighening*, as it were. Those in the light lab and those in the art studio.
The difference to me is that one is trying to reproduce the behavior of light as
faithfully as possible, the other is trying to re-create an expressive picture
of things so that this physical input can be transformed as experienced by the
human eye.

(I still say, they are not the same process but it's too hard to get into. Can't
help but try a bit: I would say that what constitutes a convincing picture is
not just what a perfect camera would record. Even photography, as Clipka points
out, is not accurate. But not because it's flawed but because photographers know
that to bump the red or distort the perspective they can acheive more dramatic
and eye-catching results. Pure simulation looks boring. TV is way
over-satruated. Why? Because that's how people want to see it. That's what
"looks good.")

All these complaints, of course, are completely unfair to those in the light lab
trying to compute the refraction of photons off a wine glass or the scattering
of the setting sun through a cloud. We seem to be seeing opposite sides of the
picture. One side assumes that by just reproducing how light is projected from
objects onto the screen that that is enough, since past that point the eye is a
mere recording device. The other that that display is just a pattern of points
of color that has to be perceived, re-seen, if you will, by the human eye to
give it coherence, meaning, and going further. artistic expression. Both have
their place. But one should not impose the limits of its view on other. And by
changing the rules of the game it makes it hard for some of us to know how to
play.

My original concerns were really pretty practical and I confess that even though
POV is, after all, a raytracer, unique in its faithfulness to the physics of
light -- time-consuming as it is, that I usually use it less as a programmable
camera than as a painter's palette, more like the java-based Processing, but in
3D. Because of their strength as languages, the downside is that you're always
working blind. You put words in the little black box, mix up the ingredients,
shake it around, put it the oven and let it bake, often for a very long time.
but never really sure how it will come out. So you have to come up with a lot of
tried and true recipes, techniques and formulas, that you rely on to predict
more or less how it will taste. My main concern was that all these hard won
recipes were now no longer reliable. Like someone put salt in the sugar bowl or
what I thought was vinegar is now sweet as milk.

My other concern has to do with the fact that all this has to be done in the
dark. So you need some kind of crutch to hold onto, a frame of reference other
than the glow from the little POV display, patiently pixel by pixel spiting out
the results. In my case, it's Photoshop, Momma or "bitch", that tells me how it
will look to others, in various situations, on different paper with different
ink on different tables. If I want to print it or web it or animate it into a
cartoon. It also gives me some way of testing it. There's nothing special about
Photoshop here (though as software goes it's pretty dependable) but since it's
what everyone uses, I know that when I try to communicate my cool little
creation to others (a web site or print house or wherever) that they will enjoy
it pretty much as I obviously hope. If I tell POV "rgb 0.5" to tell Photoshop
"rgb 128" then what do I say? I can change the definitions, of course, and say
well now 0.5 is scaled to mean 186 but the power of 2.2 is a little hard off the
top of my head.

Now from my initial tests both of these security blankets threatened to be
thrown in the washer. My recipes didn't seem to work any more and what I was
getting in Photoshop wasn't what I expected to find. Not just how it looked but
how the numbers added up. So, yes, I could rework everything and start from
scratch but let's be practical here, to try to put back together the pieces of a
broken Lego is infinitely harder than making it in the first place. Plus I can't
understand the old instruction book anymore. Then what to do? Move to a new
kitchen like Cinema 4D or Maya, where the equipment is more convenient, you can
taste test in real time, and the microwaves are faster. But these metaphors are
getting way overdone and that's about all I can say.

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