Hand tracking v14 — Reveal
The webcam hides under a grid of opaque cells and your hands wipe it open, the exposed blob outlined in white.
The camera feed sits under a grid of cells painted in a single hidden colour. Fingertips wipe cells open to expose the video underneath, and a cell fades back to hidden once the hand leaves it, so the picture is only ever as visible as your hands keep it. The blob of currently-open cells is outlined on its outer edge only, which is what makes it read as a hole rather than as a mask.
The hot path is one full-screen shader doing the composite, the cut-out outline and the camera's cover-fit in a single pass; the CPU only marks which cells a finger touched and eases each cell's fade. Everything — the video included — stays in the browser.
