Noise is a shader contract.

A native WebGL2 study of the classic procedural-effects page: one fullscreen orthographic quad, three ShaderMaterials, and a mode switch that changes the fragment program without changing the render graph.

This route preserves the source-backed direct fullscreen noise contract. The pinned page’s Stats/lil-gui presentation, exact shader chunk expansion, page/pixel fidelity, device matrix, and whole-example fidelity remain unverified.