With some help from here I generated a geometry in grasshopper and then made a surface from that geometry here is what I have so far:

Now, I want to bend the corners of that surface like this (I bend one of the corner in Rhino as an example):

Or push it down from the center of the geometry like this:

So far what I have is the geometry and the surface and I do not know how to bend it or add control points, etc. Basically what I want to do is to create a sort of a bowl and be able to change the deepness, geometry, etc.

This is what I have so far in grasshopper

Suface%20bending.gh