Am 29.11.2013 22:12, schrieb FlyerX:
> On 11/29/2013 10:08 AM, clipka wrote:
>> Am 29.11.2013 12:42, schrieb FlyerX:
>>
>>> With SSLT (marble):
>>> http://imgur.com/MoGWfDq
>>> The edges between the colors are strongly aliased. Almost looks as if AA
>>> is switched off but the edge of the sphere shows that AA is active.
>>
>> Try to avoid zero color components; for instance, you could use an
>> "average" pigment with a small bit of white mixed in. Something like
>> 0.001 shoud already be sufficient.
>>
>> What happens is that currently the SSLT code cannot yet cope with zero
>> color components, belches out a "Not a Number" (NaN) value for that
>> particular color channel, and the AA step is unable to handle that,
>> computing the average of NaN and any other valid number as NaN. The
>> image encoding algorithm then happens to encode the NaN as 0.
>>
> Clipka,
>
> Thank you very much for the tip. No wonder the red area in the render
> was completely noisy.
>
> I added the following to the material:
>
> #declare pave=pigment{average pigment_map{
>      [1 p_map1]
>      [1 color rgb 0.001]
>    }
>    }

I would instead suggest

   #declare pave=pigment{average pigment_map{
      [1 p_map1]
      [0.001 color rgb 1]
    }}

as this leaves the resulting color almost unchanged, whereas your 
solution gives any non-black color a significant blackshift.

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