The four geometries people actually report seeing — tunnel, spiral, lattice, cobweb — drawn as one stripe field in log-polar space and rotated between them, which is how the retina-to-cortex mapping produces all four from a single pattern. The spectral centroid steers the angle.
Drawn with: a WebGL2 shader.
Reacts to and looks like: gpu, webgl2 and psychedelic.
Family: Visualiser.
Runs in your browser. The preview above is the same program the renderer uses.