🕳️ 3D Black Hole Simulator: Geodesic Ray Tracing, Lensing and the Photon Ring

A real-time Schwarzschild ray tracer: every pixel integrates a null geodesic (RK4 in the Binet form) through curved spacetime, producing the shadow, photon ring, secondary image, Doppler-beamed and redshifted thin accretion disk, with a flat-space versus general-relativity split screen, a tap-to-trace ray inspector and in-page checks of the shadow radius 3√3/2 r_s, the 4GM/(bc²) deflection and the Einstein ring. Unlike the existing black-hole pages, which animate pre-drawn lensing, orbit particles or show mesh models, this one traces light rays per pixel on a Blender-baked Milky Way sky.

3D · Three.js / WebGL renderer · 60 FPS target · runs fully client-side, no install