so the butts and boobs are connected to each other? no separate sliders for either?
Correct. Though that's not exactly what I was getting at. I imagine Volition could have done separate Morph Keys for each if they wanted to, but I guess they wanted to keep things simple.
Morph Keys are essentially preset morphs of the Body/Facial Features which go at either end of the slider. So for the Vanilla "Fatness" slider, on the left you'll have a "fat-" (Skinny) morph key, and on the right, a "fat+" (Fat) morph key. The slider lets you blend between the two. In SR2, doubling up a morph key results in double the strength of the morph. So having two "fat+" morph keys on the right of the slider results in double Fatness at slider position "100".
The Vanilla "Body Style" (Gender) Slider works the same way, with a Female Morph Key on the left, and a Male Morph Key on the right. The slider blends between the two.
I believe the modern WWE games do Create-A-Wrestler morphing the same way, but for independent body parts. Which goes to show how far this system can be taken. But consider that SR2 is a 2008 Open World Xbox 360 game, with much less memory to spare.
(This video showcases what I mean quite well. It's essentially the same thing, but more advanced.)
Here is the body mesh, which is what the vast majority of characters in SR2 (including Playa) are built upon:
Regardless of how the body is morphed, it's still the same number of polygons being stretched. Having more polygons on the chest just for use with female morphs would be wasteful, as all males would also be carrying around those polygons unnecessarily, wasting resources.
