news:458ea2b9$1@news.povray.org...
>> I've experimented with that.. rendering one at 1920x1080 then downscaling 
>> to
>> 640x360.. I've also tried Gaussian average on 3x3 before and after
>> downscaling.... it's too much of a loss, and doesn't fully repair the 
>> rings.
>>
> Don't do it after rescaling, that won't fix anything and you will
> lose some sharpness. If you want to apply such a filter, do it
> before downscaling.

Yeah... what I meant is .. first I tried averaging -before- downscaling... 
and then on another copy, I tried averaging -after- downscaling.  Although 
the -before- method made better results, it still was not enough.

>
> What software and settings did you use for downscaling?
>

Software is XnView.. Settings is the simple Bilinear method... it's the 
simplest, most straight-forward, and doesn't produce the strange wavy jpegy 
edge effects that most algorithms do.  The algorithm I would prefer is... 
interpolation when increasing the size and average when decreasing size... 
but I'm still developing it in my graphics projects.

Is there anything I can do in POV-Ray?

Here's a section of code I use... so you can see I use the "disc" object and 
use the "onion" function in the object.  Is there a function I can use in 
this object that will smooth out the rough rings?

#include _ringimage
 #local ABdiff=_outer-_inner;
 #local Xring=_outer/_nscale;
 #local Malpha=_nscale*_inner/_outer;
 #local Step=ABdiff*_nscale/(_divisions*_outer);
 #local i=1;
 #while (i<=_divisions)
  object {
   disc
   {

    <0, 0, 0> y, Malpha+(i)*Step, Malpha+(i-1)*Step
    pigment
    {
     onion
     colour_map
     {
      Planet_RingMap(i)
     }
    }
    finish
    {
     ambient 0
     brilliance 1
     albedo(_ringalbedo)
    }
    scale Xring*unitscale
   }
   hollow on
   double_illuminate
  }
  #local i=i+1;
 #end

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