clipka <ano### [at] anonymousorg> wrote:
> I don't mean to dispute the fact that the assumed_gamma 1 mode
> effectively uses different defaults for ambient than the 3.6 default
> mode (in a nutshell, assumed_gamma 1 uses a factor of 0.1, whereas the
> 3.6 default effectively used a factor of 0.0064 in otherwise pitch black
> regions), but I mean to get all the facts on the table.

The ambient finish is the simplest, "cheapest" way of kind of emulating
radiosity in a simplistic renderer. POV-Ray has used it from the very
beginning so that shadowed parts (ie. surface that do not see any light
source) will not be pitch-black by default, but will be a bit visible,
simulating in a simplistic manner real life, where nothing is really
pitch-black because light bounces from surfaces to illumate things in
shadows.

It is, essentially, a kludge. Its default value is just completely
arbitrary. Something that's not too bright, not too dark. Something
that gives an acceptable default brightness in non-illuminated areas
in simple scenes. Something that when you quickly write a scene and
render it, gives you an ok result.

However, it becomes way too bright when assumed_gamma 1.0 is used.
It destroys its purpose to exist. Now it becomes a detrimental effect
rather than a useful one. Now you have to find out what the cause is,
and write additional settings to tone it back down to an acceptable
level.

I see no reason for this. It serves absolutely no useful purpose like this.
I think that by default it should remain the same brightness regardless
of what assumed_gamma is. That way it retains its original purpose (ie.
that of serving as a simplistic "radiosity" simulator for simple scenes;
not too bright, not too dark.) I see no reason why it shouldn't be like
that.

The problem with it as it is now is that when a new user, or even an
existing user, specifies assumed_gamma 1.0 as recommended, all of his
scenes will become needlessly bright, diminishing the visual quality
of the result. Usually he will not know that there's something wrong
with the ambient finish setting and that he needs to manually adjust
it. I see absolutely no reason why it should be manually adjusted in
order to retain the good-looking level of brightness. That should be
the default. You only need to adjust it if you really want some other
level of brightness.

-- 
                                                          - Warp

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