If any of you have ever seen strange dark spots blanketing your model
when using Indirect Illumination, I may have found a cure for your PW2
Here is an image in which my room size is very small. In this case
the room is just large enough to encompass the model...
You can see how blotchy the dark areas are. If you look close, you
can see the spots. Sometimes they are very obvious.
Here is an image in which I enlarged the room by several hundred
As you can see, the larger room produces a superior image.
I hope this helps someone!