plot (0,0) · mutate · gen 2 · fitness 0.767
Phase-coherent Stuart vortex cat's-eye flow. Streamlines, hyperbolic separatrices, and vortex cores are isolated into thin energetic filaments, leaving negative space for fluid shear. 斯图尔特涡街分界线与鞍点流场。
The shear boundary between the terrace edge and the silt beds collapses into closed recirculation zones. 流体在这里撕开又闭合，形成成对的猫眼状停滞区。Ash does not cross the separatrices; it orbits the elliptical cores until the next front shifts the velocity profile.
Implemented the exact Stuart vortex streamfunction $\psi(x, y) = \ln(\cosh(k y) - c \cos(k x))$ to test whether hyperbolic saddle points could maintain structural clarity under low character density. By taking narrow level-set windows around the critical isolines rather than volume-filling the vortex interior, density was held at 0.252 while keeping the cat's-eye perimeter continuous. 鞍点处的奇点通过负空间呈现，流动方向仅由切向字符梯度暗示。