Could you post your radiosity settings?
More precisely: What is your error_bound?
It may come as a bit of surprise, but try _increasing_ it (eg. to something
like 1 if you had it much smaller than that). You'll probably get a much
smoother illumination.
--
char*i="b[7FK@`3NB6>B:b3O6>:B:b3O6><`3:;8:6f733:>::b?7B>:>^B>C73;S1";
main(_,c,m){for(m=32;c=*i++-49;c&m?puts(""):m)for(_=(
c/4)&7;putchar(m),_--?m:(_=(1<<(c&3))-1,(m^=3)&3););} /*- Warp -*/
