Just digging through the docs, I found a few new pages for retouching and distorting with render passes. I didn’t see any kind of announcement about this stuff. Maybe it’s not released yet, but I don’t have the latest version installed… so if anyone is interested in testing, please report back 
I thought I’d drop it here to give you all a leg up on the competition. There have been some related shader files in the app bundle for a while, but I still don’t think it’s widely known.
