"wich" <wich_@no-spam-hotmail.com> wrote in message
news:3d52e713@news.povray.org...
>
> I have a problem with Moire effects with usign a texture with a fine
> vertical striping (simulating a trapeziod shaped vertical cladding).
>
> Any method to prevent this ugly Moire effects (see sample input)?
>
> Here is a photo that shows what I approximaty want to achieve with my
Povray
> model:
> http://www.priclad.nl/images/wallnikeklein.jpg

It isn't really something wrong with your scene file or in fact anything
much you can do to prevent it within the script. Aside from using more width
in the lines, or less color contrast (except then I believe AA [see below]
will not clean it up as well as high contrast would, a bit give and take
there).

What the trouble is involves antialiasing and you can use far more
refinement of that than the default amount to try and eliminate the moire.
Try +a0.1 +r5 and compare that to your image from before, assuming you did
only use default AA or none at all. For the INI settings, in case you are
using a INI file with that render, it would be:

Antialias=On
Antialias_Threshold=0.1
Antialias_Depth=5
Sampling_Method=1
Jitter=1.0

Note that Jitter (or +j1.0) should help to randomize pixels along edges and
so scatter the moire out some. You could also try Sampling_Method=2 (+am2)
and see if that results in a better rendering for you. If you use the second
"method" lower the Antialias_Depth to 3. Then from there you can increase it
if rendering isn't too slow for you and better results are apparent.

Read at section 5.2.6.4 Anti-Aliasing Options of the Scene Help to learn
about all this.

P.S. questions of this sort can get more response at the povray.general
group. Hopefully I've helped you out anyway.

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