image based packing of custom shape

I was hoping someone here would be able to help me with my dilemma, I am fairly new to grasshopper and cant seem to figure out how to get my desired effect. I am trying to pack a custom shape onto a dynamic surface, or a group of polysurfaces if possible, using a grayscale image to determine the size of the shape. Something like this video at around 2:00, but with my own shape instead of a circle, and along a surface. 

https://www.youtube.com/watch?v=SSWudanJc7c

Can anyone help me with this problem? Thank you!