The same emitted field.glsl() drives four scenes, switched live: snow
(flakes fluttering in the field's gusts), rain (wind-sheared streaks), fireflies
(slow wander on the field's streamlines, phase-hashed blinking) and an aurora (curtains
whose sway is the field, sampled along the arc). All advection and rendering on the GPU;
the only per-frame CPU work is a handful of uniforms. Drag to orbit, scroll to zoom.