This texture was generated in Filter Forge, a Photoshop plugin that allows you to create your own filters.
This snippet illustrates a method of using gain for bulge and pinch control and much more
Control Description
Control-1 controls the gain in the curve "this affects all examples"
Repeat
this is strictly for example 3 and uses an elevation control
Offset
this controls example 4 and can be used for curve shpes drapes and more
snippet curve gain bulge pinch