Ten particles move linearly at various constant speeds, in randomly chosen directions. For each pixel, determine the set of distances from the pixel to each particle. Sort this set. Create the adjacent difference set of this set (e.g., if the sorted set was (a,b,c,d,...) then the adjacent difference set would be (b-a,c-b,d-c,...)). Sort and repeat. Each successive set has one fewer elements than the previous set: repeat until a single number is reached. Color the pixel a grey color determined by a non-decreasing function of this final number.
Made with Processing ( processing.org ).