Oliver nous apporta ses lumieres en ce 2007/08/18 08:40:
> The solution in the end was to increase the number of photons to 100000 (I
> was using 10000 before).  Also, it was necessary (but not sufficient) to
> either make the box with the fog in it a target or make the photons
> pass_through (thanks, Christian), although making it a target didn't really
> make that much difference and only slowed things down.
> 
> I have a few other questions about this.  It seems that the number of
> photons had to be increased because the beam of light was quite narrow.  Is
> this actually the case and if so, why?
> 
> For the scattering media, I used in the end 'intervals 3 samples 40' because
> this seemed to produce acceptable results, but what is the best advice for
> choosing samples and intervals?  I read somewhere that increasing intervals
> was slower than increasing samples.

It depends on the sampling method used.
Using method 1 or 2, increasing intervals have a medium effect in the speed.
Using method 3, the default, increasing intervals have a huge impact on the 
render speed, while increasing samples have a medium to low impact. With method 
3, you need to keep intervals at 1 and increase samples as needed.
Also, with method 3, if you use 2 values for samples, the second will be ignored.

> 
> Thanks for everyone's help so far.
> 
> Regards,
> Oliver
> 
> 
> 
> 


-- 
Alain
-------------------------------------------------
I find that the harder I work, the more luck I seem to have.
Thomas Jefferson

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