Fifteen lines of physics

experiment · spring engine

01 — The whole engine

That is genuinely all of it (doubled for the y axis). While you hold an element, a stiff spring chases the cursor with heavy damping, which is why dragging feels weighty instead of glued to the pointer. The moment you let go, whatever velocity your hand had is simply left in the system — throw a sticker and it actually travels, coasts, and dies out at 3.5% per frame.

02 — Why those exact numbers

None of these came from math. They came from throwing the HIRE ME sticker at the edge of the hero a few hundred times and adjusting one digit at a time. Feel is not a formula — it is a parameter you tune with your hands.

03 — One spring, everywhere

The engine knows nothing about what it moves. Each draggable element just registers a tiny state object — position, velocity, bounds, rotation — and one shared loop integrates all of them every frame. That is why the hero stickers, the draggable name box, and every polaroid, ticket, and language pill on the about board behave identically: they are literally the same physics. Adding a new draggable thing to this site costs one line.

The bounds are computed from the real container each time you grab something, so elements bounce off the actual edges of the frame they live in — including on the about board, where the whole canvas is scaled and the math has to divide your cursor movement by the zoom factor before the spring sees it.

04 — What it taught me

Motion libraries sell you hundreds of easing curves, and none of them can answer a simple question: what happens if the user throws the thing? Easing is choreography — it plays back a decision you made earlier. Simulation is behavior — it responds to what the user actually did, at whatever speed and angle they did it. For a site whose whole argument is “this canvas is alive, touch it”, only one of those was ever going to work.