Cephalopod Skin Development Simulator
Squid, octopus, nautilus & cuttlefish are all cephalopods. They can change the color of their skin almost instantly using thousands of colored spots. These are called chromatophores. They are actually tiny elastic sacs full of pigment, which can be expanded into large disks when the squid wants to change color (kind of like a pixel on a digital display). They can also activate each other, without the squid’s brain getting involved.
This simulator models the interactions between chromatophores in a small patch of skin, as if you were looking at a squid under a microscope! When a chromatophore is stimulated, it expands visually and also stimulates its connected chromatophores.
You can be the squid’s brain by clicking within the sim area to directly stimulate a local crew of chromatophores.
Hover near the top of the sim area to play around with two simulation parameters to control (1) how quickly the activation dies down (refractory speed), and (2) how much activation spreads from unit to unit (connection strength). Here you can also reveal connections between the various chromatophore colors, restart the simulation to watch the chromatophore pattern develop, and toggle a "twitching" macro-level muscle simulation.
Source code: CephSkinDevo