The lead blade: its angle is mergeSix pairs of glass drops, one distance field per pairA spot plate with six channels, as a three.js scene, each holding a pair of glass drops (30 and 22 px) at gaps from 4 to 44 px. Each pair is one distance field whose glass surface is rebuilt as merge changes, so a pair closer than merge runs together into one piece of glass. The fan sets merge: each feeler blade stops at its own gap. At 20 px the 4, 10 and 16 px pairs have joined.