A crystal with two refractive indices splits a ray in two, and between crossed polarisers the retardation paints the Michel-Levy colours — the interference chart every petrologist reads a thin section with; the stress field is the music and a drop rotates the analyser.
Drawn with: a WebGL2 shader.
Reacts to and looks like: gpu, webgl2 and audio-reactive.
Family: Visualiser.
Runs in your browser. The preview above is the same program the renderer uses.