Explicit direct lightning

gives a lot,

unmatched quality:

A fireflies happen to appear from time to time (there is one on the ceiling for example) and, what's funny, it's a random thing while my PRNG has constant seed values.

I'm almost sure its because all threads share one random number generator and what seem to happen they are at times calling random procedure ALMOST in the same time, reassigning the values unpredictably.

Edit:

Multithreading and some GUI

Hi there,

I've added some multithreading and was playing with gui in swing.

As far as everything was a very pleasant experience, I'm concerned that
I got only ~190% load on my two cores, what means that the speedup is not exactly 2x.

So I've tested sunflowand noticed
that it also doesn't get anywhere near 200% - 180%-190% most likely. So I don't know...