Foxfire: Fungal Bioluminescence (2D)

A cross-section of a decaying log where oxygen diffuses inward from the bark and mycelium spreads cell by cell through the wood grid. Every colonised cell's glow is computed from the same real rate law as the 3D version — an Arrhenius temperature term, a Michaelis-Menten oxygen term, and moisture/decay-stage substrate factors — but here it plays out over a full 2D diffusion field rather than a discrete branching network, so you can watch the reaction actually starve at the log's core when it is thick, cold, or waterlogged.