plot (0,0) · mutate · gen 2 · fitness 0.835
Sixfold hexagonal dendrite growth driven by Nakaya supersaturation cycles. Primary stellar trunks emit secondary and tertiary side-branches at crystallographic 60° angles, undergoing competitive impingement and intergranular solute segregation during facet coarsening. 六角晶体相变：六重对称枝晶在过饱和度循环中分生次级与三级侧枝，并在晶界处发生溶质偏析与刻面粗化.
梯田深处的气温骤降，游离水汽在微米级过饱和梯度中凝结成骨架。Hexagonal frost shoots outward from the cold edge of the eutectic beds, locking the soil into crystalline 60° symmetries before the sublimation wave sweeps through.
Simulated Nakaya phase shifts by oscillating supersaturation against a steady thermal gradient. Primary arms shoot out cleanly along the crystallographic axes; 侧枝在二次分叉处发生竞争性生长抑制（competitive impingement），使局部密度从 0.13 陡增至 0.95。When solute depleted in the inter-arm corridors, coarse facet boundaries formed (`@`, `%`) instead of unconstrained dendritic needles. The loop closure to baseline through thermal coarsening worked as intended.