Spider, I can't tell exactly without the code, but it sounds like you are
experiencing a moire pattern. This is the effect where 2 frequencies are close
together and produce an undesirable harmonic. When the frequencies are linear, the
solution is to angle one relative to the other about 30 degrees.

However, yours sounds like a circular frequency where the pattern in the art is
harmonizing with the pattern of the screen pixels. To test this, render at a higher
resolution to see if the effect changes.

There is no known method to elimate moire where pixels are used, all we can do is
try to minimize the effect by making the harmonics pleasing rather than
undesireable. This is done using 4 frequencies in the printing business. In the
case of a frequency that has no direction, like the grooves in an old record, you
cannot employ the angling technique.

A secondary improvement might be achieved by altering one of the frequencies. The
frequency of your monitor might be 72 dpi and the frequency of your art might be
143 dpi producing an undesirable harmonic along the 45 degree angle. Try doing your
art at a frequency that is in golden proportion to the screen frequency ( ( sqrt 5
) +1 ) / 2

With a circular pattern you'll probably never eliminate the effect. However, in an
animation the effect can be exploited by making it change over time.

steve

Spider wrote:

> Hello. I've been modelling a bit on a pice of decoration here, one of the few
> real-life objects I've been doing after measurements and aiming for a good scale
> of things..
>
> I'm rather satisfied with the model as  it is, but I have a really hard time
> getting the texture to look "right" .
>
> It is a silver texture, fairly dull (i've got this one). But then the hard part
> comes. It's brushed in a spiral pattern (a disc in the x-z plane, radius approx
> 5 pov). I've tried using the spiral patterns, but I can't seem to get them thin
> enough to look good without a great deal of "interference"(the best description
> I have)
>
> does anyone have tips/ideas for a solution to this ?
> --
> //Spider    --  [ spi### [at] bahnhofse ]-[ http://www.bahnhof.se/~spider/ ]
> And the meek'll inherit what they damn well please
>         Get ahead, go figure, go ahead and pull the trigger
>                 Everything under the gun
>                         --"Sisters Of Mercy" -- "Under The Gun"

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