The Random Per Island attribute is a random float associated with each
connected component (island) of the mesh. It is particularly useful
when artists want to add variations to meshes composed of separate
units. Like tree leaves created using particle systems, wood planks
created using array modifiers, or abstract splines created using AN.
Reviewed By: Sergey Sharybin, Jacques Lucke
Differential Revision: https://developer.blender.org/D6154
