Andy Cocker wrote:
>
> Are the two 'before' images you linked to really transformed into these
> gorgeous images by post-processing?

Correct. That is the unmodified pov output, only 24bit because
that's jpg limitation.

> Is your process equivalent to both the
> compression and expansion techniques used in audio production...
> compressing  the peaks whilst making the softer passages 'louder'?

That's it. I just apply one transfer curve to the whole image.

> Infact, could I impose upon you and ask you to
> provide a sample scene/tutorial?

These were just tests to see if this can be done with povray. It seems
to work but as always there's a cost. Longer rendering time because
higher quality aa and maybe radiosity are required. I'm building a
more normal scene to test with textures and all and if that looks as
good as I hope then I will write a page about it. Currently it doesn't
seem to work with a more complex scene because there is still some
parameter in radiosity that's dependand on absolute scale of the scene :(

I think that currently Photoshop is the only editor that can apply
histogram and curve adjustments to 48 bit images while displaying
gamma corrected result in real time.

> I have often wished for the ability to say Lightbulb(60) or equivalent,
> and have the scene behave as much like the real world as posible,

Radiance can do this far better than pov and can even simulate how person
would see a scene. The compression is just a simple way to mimic how a
photograph of a scene might look like.

The problem with light sources is their radiation
pattern. Simple light bulbs and fluorcesent tubes pov can handle but
as soon as they are put inside a fixture with reflecting, diffusing
and translucent surfaces things get so complicated that it's just
better to guess how it would distribute the light and use spot_light(s)
for it. Indoor radiosity scenes are sensitive to the total energy
output from a light source so I'm trying to find way to relate
the spot_light parameters to the imaginary 100W bulb inside this
virtual spotlight. This would allow the scene builder to say:
This is a 100W light source and I'm going to use this spot_light(s)
to approximate it's radiation pattern. When there is only one light
source the strength can be chosen at will but when there are several
sources their relative strenghts are important.


_____________
Kari Kivisalo

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