Mesh Sphere Collision

Hello,

I am trying to make my script work with having a mesh that I create that then can be altered by the spheres. The script uses Kangaroo. 

It works when I have a mesh or rectangle made in grasshopper but not if I try to input a mesh from grasshopper.

The error that I get in the script is from kangaroo and reads:

1. Solution exception: object reference not set to an instance of an object

I would like to be able to input my own mesh so as to increase the density of the mesh and to create different mesh types such as a circle. Also Eventually I would like to create meshes with holes and see the different effects.

I have attached the script that I am using and a drawing that I created from the script which is the outcome that I want but with an increased density.

Any help would be really appreciated as I have tried many different solutions but with no success. 

Thank you

Rebecca