09 — Lab
Nothing here moves
until you do.
Every motion on this site comes from physics that you start: Verlet integration for threads and cloth, a wave equation for water, and Snell's law for glass. Nothing is keyframed, and nothing runs once it has come to rest.
09.1Thread
Position Verlet with SHAKE links and long-range tethers. It hangs as a solved catenary and starts at rest. Drag it, or sweep through it: the air you move pushes it.
09.2Water
Damped wave equation with a surface-tension term, integrated with Verlet (leapfrog) on the GPU. Short ripples outrun long ones, as they do in real water. The page is refracted with Snell's law at n = 1.333 and lit by the caustics the same surface focuses. Move through it, or click to drop.
09.3Glass and water
A soft Verlet ring (surface tension and incompressibility) carrying a spherical-cap lens. It refracts eight wavelengths with Cauchy dispersion and focuses the key light into a caustic, with a shadow ring around it. Drag it, or focus it and use the arrow keys. Current material: Water, nd = 1.333, Abbe V = 55.5.
09.4The grid is fabric
The 12-column layout grid as woven cloth: structural, shear and bending constraints with separate compliances, hung on gathered hooks so it falls in real folds. Pull any crossing.