OK that's how I did it as well in one process of trying to recreate this effect.
I didn't quite go to the extent as you did Vector Doctor.
Then I tried to do it by making a vector pattern using diamonds.
But it was getting very very time consuming. I think the Vector Doctor is right on with his way then applying a clipping mask for the shape you want it on. Vector Doctor can you tell me if you used a grid or guides or something to get the spacing and sizing differences exact. Thanks for the help guy's