Coral colonies grow as polyps bud and branch outward toward light and current-borne nutrients, producing the fractal branching structures seen on real reefs. Five colonies are generated with a recursive branch algorithm (depth 5-7, 2-4 children per branch) and animated with a custom vertex shader injected via onBeforeCompile that sways branches based on height and simulated current strength. A 180-strong InstancedMesh fish school orbits the reef, and additive-blended plane "god ray" shafts fake volumetric light.