On 8/26/25 19:42, Cousin Ricky wrote:
> Cousin Ricky <ric### [at] yahoocom> wrote:
>> I'm taking a stab at reproducing Bruno Cabbason's "Extreme optics," but
>> as far as I can tell, he has not published his source code.
> 
> Yikes!  I just noticed I spelled "Cabasson" wrong.  My apologies.
> 
> 

And, I followed right along... :-(

I don't recall ever seeing that image. It's really cool! For others who 
might have been distracted too at the time:

https://news.povray.org/povray.binaries.images/thread/%3Cweb.4d54f6b329b411e54aa45fdf0@news.povray.org%3E/

He mentioned having to run with jitter off to avoid splotchy results - 
but then getting the banding (interference fringes). I think the banding 
spoken about is likely the photon distribution issue mentioned 
previously in this thread - which is fixed in the yuqk fork. Attached an 
image of your scene (plus previously mentioned adjustments), global 
photon jitter off, no AA, with v38 results on the top and yuqk on the 
bottom (1).

---

Aside: Puzzling performance results. I am unsure why yuqk is so much 
faster with the scene set up for the attached image?

v3.7
577.29user 0.33system 2:42.95elapsed 354%CPU

v3.8 beta 2
572.11user 0.35system 2:33.45elapsed 373%CPU

yuqk
105.71user 0.13system 0:33.08elapsed 320%CPU

Bill P.

(1) - Yuqk's global photon jitter on|off results look pretty much the same.

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