ZBrushCentral

Knifebrush and Bradius turned on, but not creeting polygroups

Hi everybody. My question : I want to do some slicing with the knifebrush I have turned on Bradius turned on+polygroups, but its not creating any new polygroups when I slice. I’m on latest build. Anybody?

I forgot It needed thickness. Then It works. I was cutting on plane only.