#409Fresnel Lens

A lighthouse Fresnel lens, collapsed to a face-on disc of concentric facet zones. Each ring carries a sloped riser — steeper the farther out it sits — so a sawtooth of the radius stands in for the ridged glass. A pseudo-3D facet normal catches a sweeping light, and the grooves flare into arcs of highlight on the lit side, brightest where the risers step. All of that light is gathered to a single hot focus that blooms at the core and throws a collimated shaft back out along the beam — the lighthouse turning. Scroll to add or drop ring zones; hover to steer the light.