How does one contraction crack affect the growth of subsequent cracks?

i) Draw an example of the cracking pattern to be expected in a material experiencing uniform contraction, starting with a single initial crack shown in the diagram. Choose cracks that originate at random within the space, and propagate both directions. Assume that a crack alters the stress field over a distance of about 1 cm.

ii) How do you know when to stop this drawing? (is the pattern a fractal?)

iii) Find an example of such a surface (my coffee mug’s glaze is an excellent example as I write this question)