A pane of fogged glass is a lens factory.
Breath and cold do the work. The whole surface hazes over — a thousand tiny beads of condensation, each too small to see through, together soft enough to turn a city into a field of warm, drifting bokeh.
Then gravity finds the heavier ones. A drop gathers weight, hesitates at the top of the glass, and slides — swallowing beads as it goes, growing, leaving a clear wet trail where the fog is wiped away.
Look closely at a single running drop. It is a real lens: it bends and magnifies the lights behind it, flips them, and sharpens what the fog had blurred. A whole city, rendered upside-down, held for a second inside a bead of water.
Every effect on this page is that optics, computed live in a fragment shader — a height-field of drops perturbing the light behind the glass. Drag to wipe the mist. Click to leave a new drop.
The train hums a note it has hummed a thousand nights.
Platforms slide past like slow film. Sodium orange, a stray cyan sign, the amber wash of a window still lit in a tower where someone is also awake. The carriage is warm and nearly empty. You could sleep. You don't. You watch the rain rearrange the skyline, drop by drop, and let the day come apart quietly behind the glass.
Distance is just light, slightly blurred.
The far things go soft; the near things sharpen and slide away. Somewhere out there is a street you'd know in the dark, a door, a lamp left on. From here it's only a smear of warm colour on cold glass — but you're moving toward it, one drop, one platform, one held breath at a time.