PhysX cloth: change/set rest values

Hello everybody,
I am developing a clothes editor, and for my purpose some connection between cloth’s particles needs to be set to a rest value different from initial distance. This because I don’t know the final shape.
It is possible create a PxClothFabric specifying the rest values?, or change them?
The best would be change them on PxCloth…
Antonino Perricone