Ovikar

Ovikar is a crease-pattern designer built for anyone who wants to go further than paper diagrams allow. Draw mountain and valley folds directly on a sheet, then watch the pattern fold itself in real time — dragging one handle takes it from flat to fully collapsed at frame rate, with no commit button and no waiting. The engine checks your work as you draw. Every interior vertex is evaluated against Maekawa's theorem, Kawasaki's theorem, and the Big-Little-Big rule simultaneously. When a vertex cannot fold flat, Ovikar tells you exactly which one and exactly why — something no printed diagram and no drawing app does. Tap any theorem result to jump straight to the Glossary entry that explains the maths behind it. Four tessellation families — Miura, tapered Miura, arched Miura, and Herringbone — are computed in closed form from a single fold parameter, so every metric updates live as you scrub: compression ratio, footprint, height, measured Poisson ratio, total crease length, and layer-stack height. The same flat-foldability analysis runs on patterns you draw yourself, vertex by vertex. The Model Library ships with a set of classic patterns, each rendered by the same engine and each carrying its own verdict badge — because some well-known patterns are not flat-foldable, and Ovikar will not pretend otherwise. Export a print-ready crease sheet at true 1:1 scale, pair folded-model photos with their patterns in the Gallery, and step through the derived fold sequence one precrease at a time, with a live 3D inset showing the partial state at every step. Everything works offline.