Thomas de Groot wrote:
> This is almost 'perfect' :-)
> Still a bit of artifacts visible, but not much.
> Essentially, what I have changed since the preceding render are:
> increasing nearest_count to 10
> increasing error_bound at 0.5 in the first pass
> increasing low_error_factor to 0.9
> increasing count to 250
> decreasing recursion_limit to 2
> decreasing brightness to 0.8 in the second pass

It looks much better (although difficult to judge at this small size) 
but under the aspect of the argument i gave concerning the adaptive 
error_bound using a higher one in the pretrace than in the final trace 
is counterproductive.  Of course the adaptation will automatically 
increase it in the final pass but this will make it slower than 
necessary.  If you set the starting value of the adaptation to the same 
as in the pretrace this will probably make it quite a bit faster and not 
much worse (although it is difficult to say for sure). Since there have 
not been a lot of tests made with the adaptive error_bound it might be 
interesting to see the (non-jpeg-compressed) results of this in 
comparison.   If you could quote the number of samples taken in pretrace 
and in the final pass that would also help to say if these assumptions 
are correct.

BTW using different brightness in two passes is handled by POV-Ray AFAIK 
but there is not much point in doing this.

Christoph

-- 
POV-Ray tutorials, include files, Landscape of the week:
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