POV-Ray : Newsgroups : povray.documentation.inbuilt : Anti-aliasing mode 3 : Re: Anti-aliasing mode 3 Server Time
1 Dec 2021 05:14:15 EST (-0500)
  Re: Anti-aliasing mode 3  
From: clipka
Date: 22 Sep 2018 19:39:36
Message: <5ba6d2b8$1@news.povray.org>
Am 23.09.2018 um 00:26 schrieb Jim Holsenback:

> please review:
> 
> http://wiki.povray.org/content/Reference:Tracing_Options#Anti-Aliasing_Options

My thoughts on it:


Stochastic Seed:

- Typo: "Set's a value" should read "Sets a value".

Sampling Methods Synopsis:

- Excellent! Love this mini section!

Details, Type 1:

- The section states that "the adaptive non-recursive method is the
default". I would suggest adding "if anti-aliasing is enabled" or
something along those lines, because the "out of the box" default is no
anti-aliasing at all.

- It may or may not be worth also considering an optional alpha channel
in the formula given (but see further below).

Details, Type 3:

- The formula for the actual maximum number of rays per pixel is
literally written as "4^n" (four-caret-n), rather than using proper
superscript notation. Not sure if this is an oversight or technical
necessity. In the latter case, maybe Unicode character U+207F would be
an alternative to genuine superscript.

- The word "moire" in "moire pattern" lacks an accent.

Common section:

- The common section ("With all methods..."), as currently written,
implies that the `Jitter` setting affects all anti-aliasing modes; that
is incorrect: Anti-aliasing mode 3 always uses a constant amount of
jitter. I would suggest to use something like the following wording instead:

----------------------------------------------------------
Another way to reduce anti-aliasing artifacts is to introduce noise into
the sampling process. This is called jittering and works because the
human visual system is much more forgiving to noise than it is to
regular patterns, and is inherent in anti-aliasing mode 3. When using
one of the other methods, the location of the super-samples is also
jittered or wiggled a tiny amount jittering by default, but may be
turned off with the Jitter=off option or -J option, or the amount of
jittering can be set with the Jitter_Amount=n.n option. When using
switches the jitter scale may be specified after the +Jn.n option. For
example +J0.5 uses half the normal jitter. The default amount of 1.0 is
the maximum jitter which will insure that all super-samples remain
inside the original pixel.
-----------------------------------------------------------

Additional noteworthy information:

- It may be worth noting that if the image contains an alpha channel,
that channel will also be considered in the comparisons, pretty much
like the colour channels, except that unlike the other channels it is
not subject to `Antialias_Gamma`.


> besides the am3 additions i also did some general cleanup and added a
> few visual cues to help better separate the method detail descriptions

Would it make sense to use sub-headings instead of just bold text?

Also, I guess it might be useful to add another visual cue between the
type 3 description and the subsequent description of common features.


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