Revisited: Clothing shape change with Genesis 3/4 movement (but not Genesis 1/2)

wizardofozz47

I posed a question about similar content some time ago, but I figured I'd try asking about it differently since I never figured it out.  Basically I am trying to understand what it is about certain clothing that allows it to move and deform in a 'life-like' fashion when Genesis 3 (and 8) are bent in one way or another.  Note that I have only oberved this phenomenon with a small handful of clothing products, and it only works when those items are fit onto Genesis 3 or 8.  Pictured below is a side-by-side of Genesis 1 (background) and Genesis 3 (foreground) wearing the same shirt (H&C skinny jeans top, to be exact).  As can be seen in the image, the shirt changes shape on its own to fit Genesis 3 as she is bent forward, and flattens out like a real shirt (and does something entirely different when she is bent backwards or sideways).  On Genesis 1, the shirt really doesn't change shape at all, but instead clumps up in the front and stays rigid in the back.

What I would like to do is be able to tell the shirt to behave on Genesis 1/2 the same way that it does on Genesis 3.  I want to know if it is possible to make other clothes that normally do not exhibit this property do so.  This all might not actually be possible of course.  In the past, people have suggested looking into weight mapping, which I have been doing.  While weight mapping might be a factor here, I can't help but feel like I am missing something very basic that allows the clothing to conform in different ways to one model as that model is posed (and conversely why it does NOT work when those clothes are put on another model).

Any ideas?