Okay... I'm pulling my hair out, and there must be something I'm missing...

I have modeled a simple skirt that I'd like to turn into a conforming figure.  I'd like the skirt to have a "sit" morph.  It does not seem to matter how I group the mesh to the bones, I cannot get the skirt to deform correctly when Vicky's thighs are bent much past 15 degrees.  Either her skirt is embedded halfway into her thighs, or there's a line of cloth between her legs that doesn't move up in the back... or both!   I've had somewhat better luck with shorts/pants than skirts, but am having similar issues with that too.  (Shirts are okay... perhaps Vicky will just go pantless?  giggle)

There must be something I'm missing here.  Can anyone offer some tips?  Tutorial?  Anything?  Do I need extra bones? More subdivisions in my mesh?  A FORK to poke in my eye??

My modeling was done mostly in 3ds max, which I'm admittedly VERY new to...  But the skirt fits delightfully in every other case, just not when conformed while V4's legs are bent in a sitting pose.

Help?

Thanks!

Intel Core i7-8700 6-Core 3.2 GHz (4.6 GHz Turbo), 32GB RAM, two GeForce GTX 1080 Ti GPUs

DS 4.10, Photoshop CC and CS6, Poser 11 Pro, Vue 2016, CarraraPro 64bit, Autodesk Inventor, Mudbox, and 3DS Max

One in 68 children is diagnosed with autism.  One is mine. ♥