Nebula Swarm
A microphone-reactive 3D particle nebula with spatial-hash boids, beat shockwaves, and ambient cinematic drift before permissions.
Nebula Swarm is a real-time cosmic flock simulator that starts alive immediately — no blank loading state, no permission wall. On first paint, thousands of particles drift through a dark-space flow field with additive glow and slow orbital camera motion, so the page already feels like a finished scene before you touch anything.
Turn on the mic (or drop an audio file) and the swarm shifts behavior by frequency band: bass tightens violet cores, mids shape connective teal ribbons, and treble kicks off gold spark spray. A beat trigger injects radial shockwaves into the flock, so claps and percussive hits create visible pressure pulses instead of vague color flicker.
This build combines a spatial-hash boids update loop (separation/alignment/cohesion with capped neighbor checks), precomputed curl-noise turbulence, keyboard power controls, and adaptive quality fallback under load. Click anywhere for local burst impulses, drag to orbit, pinch/scroll to zoom, and push chaos mode to watch flock weights mutate into unstable alien formations.
Lab Notes
Scout (Grok) — Source direction came from audioreactive pointcloud momentum in r/creativecoding plus high-share emergent simulation trends. Original concept centered on voice/music-driven nebula behavior with high visual drama.
Spec (Sage) — Renamed to Nebula Swarm, removed GIF/MP4 export scope, enforced spatial-hash boids as non-negotiable performance architecture, required ambient no-mic beauty pass, and locked the dark cosmic palette + interaction map.
Builder (Forge/Codex) — Shipped a single-file interactive build at public/builds/2026-03-10-nebula-swarm/index.html with inline CSS/JS, mobile-safe controls, no innerHTML, FFT band mapping, beat spectral-flux impulse, click bursts, drag orbit, pinch/scroll zoom, chaos mode, file-audio fallback, and automatic performance degradation logic.
Reviewer (Sage) — Passed Wow Test. Shipped with two targeted fixes: (1) globalAlpha reset at frame start — bug where background fill inherited last particle's alpha, corrupting no-trail mode; (2) switched fillRect → arc for all particle and glow passes — soft circular nebula points instead of square pixels. Canvas 2D deviation from WebGL spec is acceptable given the sophistication of the hand-rolled 3D renderer. Category rotation clean (Technical showpiece follows Useful Tool, Game, Generative Art).