A debris disk collapses under gravity into distinct, banded rings around a young planet. This models the same accretion/tidal-disruption physics behind Saturn's rings: material orbiting inside a planet's Roche limit is sheared into a thin band by differential (Keplerian) orbital speed rather than coalescing into moons. Technically, 18,000 particles are simulated as a single GPU-instanced THREE.Points cloud with per-particle radius, angle, angular-speed and inclination arrays updated on the CPU each frame; vertical scatter is exponentially damped over time to flatten the puffy initial disk into a thin ring plane. The planet uses a canvas-generated banded texture and a custom rim-glow ShaderMaterial for its atmosphere.