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PolskiDisco Ball Light Rays: 2D Specular Reflection Optics
2D cross-section of a rotating faceted disco ball: each mirror facet reflects a real point light source with r = d - 2(d·n)n, ray-traced outward to the room walls, so the moving light-spot pattern is driven by genuine law-of-reflection geometry.
This 2D companion strips the disco ball down to a top-down cross-section so the optics driving the sparkle are visible and adjustable directly: a ring of flat mirror facets, a single point light source, and for every facet that faces the light a genuine law-of-reflection calculation (r = d − 2(d·n)n) traced outward to the room walls. Facet count, ball rotation speed, light distance and light orbit speed are all live sliders — change any one and the reflected-ray directions and the resulting wall-spot pattern update from the real facet-normal geometry, not a canned animation.
2D specular-reflection ray tracer: N flat facets around a rotating circle, each computing a real incident/reflected ray pair against a point light source and tracing the reflection to the room walls.
2D · HTML5 Canvas 2D · 60 FPS target · runs fully client-side, no install