[Radiance-general] mkillum with 400 sources?

[Lars O. Grobe]

Hi Greg,

thanks for your reply.  In fact, I am using surfaces not for each pane, 
but for each opening now, so that is why I have "only" these 400 faces 
;-) I tried reducing -ab, -ad and -as, but rendering times are *really* 
slow now. I have all these zero-radiance illums (sealings), do they 
have an effect on the rendering speed, even when zero?

You know the scene, it is this church scene I showed you, so it has a 
lot of these small windows, and as the fenestration is rather complex, 
I hoped that using illum "coffers" around the windows would improve 
rendering speed as well as accuracy. However, so far the speed is 
really disastrous. Outside the building, there is not much detail. I 
even tried to apply skyfunc to the window panes, but as I have to apply 
it to *every* small pane than (because I can't use the coffer trick to 
integrate the whole window than), I get so many hundreds of light 
sources that calculation is almost impossible.

TIA+CU Lars.

> Putting illum surfaces inside of your windows rather than using a 
> separate surface for each window pane is one way to reduce calculation 
> times if your mullions are not particularly large or prominent.
>
> All else being equal, you can reduce -ab by 1 and decrease -ad and -as 
> (by a factor of 2 or so) and even increase -aa by 50% and still get 
> similar results.  However, you may also have to set -dj .8 and -ps 1, 
> which will undermine the calculation speeds a bit.  Overall, illum's 
> pay off most when you have smaller windows or skylights and/or complex 
> goings on outside.