Looking for JFF tutorial which could explain me how 2 add buttcheecks collisions

[Iolya]

Hey, everyone!

 

I'm looking for a tutorial which could explain me a thing or two about adding collisions to the body. What I want to do is to add collisions to left and right buttcheecks and, AFAIK,  JFF is capable of doing this, but I just don't know what to start with, which parameters should I change and which I shouldn't etc. Could anyone please point me towards a guide which explains that topic? Or, if it is not so hard, I would've been very grateful if someone could explain me how to do this step by step.

 

Either way, thank you in advance for your help!