HELP:Barnacle pattern on srf/mesh

Hi everyone, I am new here.

I am doing a school design project to create a barnacle patterns on a wall (the wall could be srf or mesh, mesh preferred). The pattern should show randomness. I have tried several different methods but they are not as successful as expected. 

Actually I found a similar script online shows exactly what I want but the first half of it is missing. 

If you have any suggestions please post here I am highly appreciated.