A Topological Picture Book, Rendered

This interactive visualization renders topological surfaces like the torus using hand-hatched line drawing techniques inspired by mid-century mathematical illustrators. The tool allows users to manipulate 3D parametric or implicit surfaces while applying artistic effects such as principal curvature hatching, silhouette contours, hidden line rendering, and hand-lettered labels to create aesthetic mathematical diagrams. The rendering is stroke-based rather than pixel-based, employing GPU-accelerated visibility calculations and carefully tuned effects like ink pooling and paper bleed to emulate classical mathematical illustration styles.