POV-Ray : Newsgroups : povray.advanced-users : Speeding up media : Re: Speeding up media Server Time
6 Jul 2022 18:50:50 EDT (-0400)
  Re: Speeding up media  
From: Alain Martel
Date: 17 Feb 2021 11:40:01
Message: <602d46e1$1@news.povray.org>
Le 2021-02-17 à 08:23, William F Pokorny a écrit :
> On 2/15/21 6:58 PM, Alain Martel wrote:
>> Le 2021-02-15 à 06:00, William F Pokorny a écrit :
>>
>>> (a) For the purposes of documentation see (a1) and ignore the rest of 
>>> this footnote. Someone can set the intervals in method 3 to more than 
>>> 1 and if they do ratio does come into play with a lit and un-lit 
>>> intervals scheme internally which 'probably' doesn't have much of an 
>>> end effect for method 3, but... Always true, sometimes, almost never, 
>>> never? Not sure... When using multiple medias with mixed sampling 
>>> types, I know of some bleed through in the keyword settings between 
>>> methods.
>>>
>>> Bill P.
>>>
>>>
>>
>> This probably explain why using several intervals bog down method 3 so 
>> much. It tries to compute ratios and variances when it's not needed.
> 
> Only ratios(a) I believe, but yes, expect this a part of the typical 
> slow down (always? sometimes not?). I don't understand all the whys.
> 
> The most obvious reason is the number of interval acts as a multiplier 
> for the starting number of samples with method 3 and this is 10.
> 
> (a) and the underlying light interval stuff. This code is tied to light 
> types. My guess is it's aimed at speeding up (or better resolving 
> perhaps?) spotlights and cylindrical lighting when using media(a1). 
> Maybe it all more or less works - but I have doubts about how well 
> beyond the simplest test set ups. I'd like to pull all the lit/unlit 
> interval code out too.
> 
> Bill P.

In my testings, intervals 5 samples 10 run MUCH slower than samples 100 
and default intervals 1.


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