> Now I have a question .... because holy crap my first stab at photons in
> this scene took 28 hrs and it just didn't suit. I think some of the rays
> are getting through the gaps between the peppercorns. I've been reading
> (and re-reading) the docs on photons and I'm unclear about the setup I'm
> using. I'd like to trim some time off that process and here's what I have:
>
> union {
>    object { PepperMill scale 1.01 #if (UsePhotons) split_union off #end }
>    object { Peppercorns #if (UsePhotons) split_union off #end }
>    translate <-120,0,12.5>
>    rotate y*60
>    #if (UsePhotons)
>      photons { target reflection on refraction on collect off }
>    #end
>    }
>
> The peppercorns are a union of all the peppercorns is why I did it like
> that, and just wanted a reality check so I don't waste another 28 hrs!

I'm not sure that turning split_union off help you. If the union is 
split, you stop checking if you hit any object of the union, but, if you 
don't split it, each ray must test against all of your 2000 peper corns, 
even those on the oposite side or in the middle that have no hope of 
ever interacting with your photons...
Anyway, do a test using only mockup spheres and one photons target 
object shining photons on the whole thing. Compare with and without 
split_union off.

Not splitting the union of the peper mill itself may help in some cases, 
but it also may not.
Do a test render with the empty peper mill and simple planes to collect 
the photons and compare the performances with and without split_union off.

You don't need to use the conditional expression for your photons block. 
In a non-photons scene, any photons block is just silently ignored.


Alain

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