Take a doubly-curved or twisted surface and find out how many of its panels are genuinely different. Six built-in surfaces that each fail differently (saddle, dome, torus, twisted tower, freeform roof, and a developable cone as the control), or import a quad mesh (OBJ, Relax's OBJ, a Rhino .3dm mesh). Measure exact planarity, paint the curvature field, classify every panel FLAT / COLD-BENDABLE / HOT-BENT and read the UNIQUE PART COUNT — how many moulds it would really take. A repetition slider loosens the leash and snaps panels onto shared moulds — the part count falls, the surface visibly deviates, and both numbers sit side by side.
Runs entirely in your browser — nothing is uploaded, no account needed for the solver. A teaching rationalizer: the planarity measurement is exact, the planarize solve is first-order (it stalls honestly where the net fights the surface), and the unique-part count is an upper bound, never a quote. The optional coach requires sign-in.