3D Geometry — Interactive Interview Prep

An interactive 3D playground for the geometry that shows up in graphics, game-engine, robotics and computer-vision interviews. Thirteen draggable scenes — dot & cross products, point-to-line and point-to-plane distance, reflection, ray–plane and ray–sphere intersection, line–line closest points, sphere–sphere and AABB collisions, sphere–plane, barycentric coordinates / point-in-triangle, and a nested-gimbal rotation demo that makes gimbal lock visible — each recomputes its formula, live values and edge cases as you drag. Plus knowledge cards covering rotation representations, transforming normals, handedness, an intersection cheatsheet, numerical gotchas and a drillable interview question bank. Built with Vite + Three.js.