I start to think that after all, Global Illumination system that TG boasts every now and then is either not working at all or too tough to set up. One way or another, it is so cumbersome for me that I'm back to using FILL LIGHTS! ???
I have a part of a rock arch that is covered from sunlight and it is ALWAYS BLACK no matter how many ways I try to tweak the settings. I tried various configurations, increasing ambient light power and the shadow part is just pitch-black, regardless of GISD, cache detail, sample quality or whatever else there is in this stupid GI window. It just doesn't make a difference.
There are also no clouds yet in the scene apart from a touch of cirrus clouds. Something is completely messed up with that thing. ??? Perhaps it is time to revise it...?
Well, this might be a less-than-friendly rant but it is not the first time. I'm quite frustrated with subtle lighting effects in TG by now...
No image and no file to look at it?
Not saying that there are no problems but with a file to see and test we could see at least if or where the problem is.
I'm sure there is something else that's causing your frustration. I can't remember any problem I had with GI. As Kadri said a file would be nice.
Yes, we'd really like to help, but we can't do much without seeing an image showing the issue, or better yet a TGD. I'm sorry to hear you're so frustrated though. Hopefully we can figure it out together.
If you're anything like me it will be an unclamped black somewhere ;)