Diffusion-reaction systems were an inspiration in general. Using a Laplace operator (or the discretised equivalent for our 2D grid) might have trouble learning

Diffusion-reaction systems were an inspiration in general. Using a Laplace operator (or the discretised equivalent for our 2D grid) might have trouble learning to generate these patterns - the Laplacian wouldn’t always provide unique information as to where a cell might be based on its neighbours. It’s possible the network would learn to exploit the hidden channels to bypass this directional invariance. Starting from a single pixel in such a setting would indeed need some mechanism to break the symmetry (stochastic updates as used here, for instance).