Dithering is a technique to avoid banding or moire patterns. This technique consists in a probabilistic choice of values instead of a deterministic one. Photoshop has a dithering filter called “Spatter”, while Gimp offers precise options for dithering purposes.
However, using an external image editor to reduce the range of a number of values is cumbersome and unnacurate, so I strove to get it right inside of Grasshopper. The strategy lies in creating a weighted list of (0,1) values which will be picked with a random number. One of the issues to get it right is to use a different seed in each value picking.
In this image, you see the cluster in action:
Here is the inside of the cluster:
Undesired results which led to the creation of the above algorithm:
a) R domain of values; b) Banding effect