BBP (only boobs) and TBBP (boobs and butts) are for animations, they only work with animations compatible to them and will always make the same movement fixed by the animations you use (dragonfly for exemple). HDT is physics, that means that even if you use vanilla animations (not modified for movement) the breasts and butts will move depending on movement and may act different ways. You should always look for armors that are HDT as they are weighted for it but BBP and TBBP are compatible, you just won't get butt movement on BBP. For Collision (google is your friend): 1 - Download Nifskope or "HDT Collision by head" somewhere here on LL. 2 - Download a XML that is collision enabled like Minou's. 3 - Download HDT Havok Object to enable it to NPCs. 4 - Make the HDT body/armor, install hdtPhysics latest version, overwrite with the collision XML. 5- Link the XML to the femalehead.nif if you didn't just get the "HDT Collision by head". 6 - ??? 7 - Profit!!! I'll attach my XML for test or use. It's a modified version of Minou's hdtPhysics, I put more movement in the butts, breasts and some collision on the arms. hdtPhysicsExtensionsDefaultBBP.xml