i m piLLo.
i would like to share with you a strange (but it may be normal) thing happened to me.
i was simulating light behavior in a bilding (using radiance, as usual) and in particular i was calculating DGI indexes for different points at different time.
the strange thing is that DGI values are sometimes minor than zero...

the answer is: is it possible and what does it means? (...a part that i m a beginner...)