Antialiasing removes the details of a background, so that
something like flames, explosions and starfields get severely
impacted by the process. In some cases, totally removed
from the picture. Is there a way to only antialias specific
objects? Or is this a post-process only?
Thanks in advance!
=Bob=

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In article <40030368$1@news.povray.org> , "=Bob=" 
<was### [at] threestrandscom> wrote:

> Antialiasing removes the details of a background,

Antialiasing does not remove any details!  Probably you are misinterpreting
what you see.  Posting a short sample scene will allow others to help you to
adjust your scene such that details do not disappear.

    Thorsten

____________________________________________________
Thorsten Froehlich, Duisburg, Germany
e-mail: tho### [at] trfde

Visit POV-Ray on the web: http://mac.povray.org

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> Antialiasing removes the details of a background
Anti-alias works in a realistic and natural way.

> so that something like flames, explosions and starfields
> get severely impacted by the process.
Only to the same degree as photos.

> In some cases, totally removed from the picture.
The stars are too small then.

> Is there a way to only antialias specific objects?
No, currently not with POV-Ray.

> Or is this a post-process only?
Post-processing anti-alias is possible, but is a rather cumbersome method.

I agree with Thorsten; if you post an image maybe we can help you find a
solution to the problem.

Regards,
Hugo

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"Thorsten Froehlich" <tho### [at] trfde> wrote in message
news:40030971@news.povray.org...
: In article <40030368$1@news.povray.org> , "=Bob="
: <was### [at] threestrandscom> wrote:
: > Antialiasing removes the details of a background,
: Antialiasing does not remove any details!  Probably you are misinterpreting
: what you see.  Posting a short sample scene will allow others to help you to
: adjust your scene such that details do not disappear.
:     Thorsten

See p.b.i "antialiasing problems"
=Bob=

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"Hugo Asm" <hua### [at] post3teledk> wrote in message news:40031ac1$1@news.povray.org...
: > Antialiasing removes the details of a background
: Anti-alias works in a realistic and natural way.
:
: > so that something like flames, explosions and starfields
: > get severely impacted by the process.
: Only to the same degree as photos.
:
: > In some cases, totally removed from the picture.
: The stars are too small then.
:
: > Is there a way to only antialias specific objects?
: No, currently not with POV-Ray.
:
: > Or is this a post-process only?
: Post-processing anti-alias is possible, but is a rather cumbersome method.
:
: I agree with Thorsten; if you post an image maybe we can help you find a
: solution to the problem.
:
: Regards,
: Hugo

See p.b.i "antialiasing problems"
=Bob=

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=Bob= wrote:
> 
> Antialiasing removes the details of a background, so that
> something like flames, explosions and starfields get severely
> impacted by the process.

You can code your starfields so that each star is guaranteed to be hit
by at least one ray.  That will ensure that no stars drop out.

Regards,
John

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> Antialiasing removes the details of a background

The real problem is that *aliasing* causes artifacts. An image should not
rely on aliasing for special effects, because it is mathematically
innacurate and produces poor images.

Therefore, the best solution here is to design starfields / flames /
explosions so that they don't rely on aliasing.

I've never seen flame/explosion problems related to aliasing, but the
starfield problem is a common one. It can be avoided by using actual objects
randomly placed in the sky as stars, or by texturing more carefully so that
a star is about one pixel wide in size.

 - Slime
 [ http://www.slimeland.com/ ]

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Slime <fak### [at] emailaddress> wrote:
> The real problem is that *aliasing* causes artifacts.

  What do you mean? Antialiasing *removes* artifacts. Aliasing artifacts,
to be more exact.

produces a more photorealistic image.

  If a starfield is based on making a pigment with white spots of
size 1/100 of a pixel, what do you expect antialising to do?
The fact that such 1/100 size of a pixel spot covers the whole pixel
is an artifact. Being that small it should be almost invisible, and
that's what antialiasing does.

  This trick relies on the artifact (which antialiasing tries to correct)
and thus no antialiasing can be used with it.
  In other words, the starfield pigment is based on an artifact. It's not
antialising which causes the artifact.

-- 
#macro M(A,N,D,L)plane{-z,-9pigment{mandel L*9translate N color_map{[0rgb x]
[1rgb 9]}scale<D,D*3D>*1e3}rotate y*A*8}#end M(-3<1.206434.28623>70,7)M(
-1<.7438.1795>1,20)M(1<.77595.13699>30,20)M(3<.75923.07145>80,99)// - Warp -

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> > The real problem is that *aliasing* causes artifacts.
>
>   What do you mean? Antialiasing *removes* artifacts. Aliasing artifacts,
> to be more exact.

Right, you're saying exactly what I was saying. Note that I said "aliasing
causes artifacts"; not "antialiasing causes artifacts".

 - Slime
 [ http://www.slimeland.com/ ]

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Slime <fak### [at] emailaddress> wrote:
> Right, you're saying exactly what I was saying. Note that I said "aliasing
> causes artifacts"; not "antialiasing causes artifacts".

  Ooops! My mistake... :)

-- 
#macro M(A,N,D,L)plane{-z,-9pigment{mandel L*9translate N color_map{[0rgb x]
[1rgb 9]}scale<D,D*3D>*1e3}rotate y*A*8}#end M(-3<1.206434.28623>70,7)M(
-1<.7438.1795>1,20)M(1<.77595.13699>30,20)M(3<.75923.07145>80,99)// - Warp -

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