Implements god ray / crepuscular ray effect using cone-shaped meshes
with custom GLSL shaders and additive blending. Nine rays emanate from
the upper skybox at varied angles, colors (gold, blue, cyan), and phases.
Each ray has animated shimmer rippling down its length.
Also establishes the full Three.js scene foundation:
- Renderer with ACESFilmic tone mapping + UnrealBloom post-processing
- Star field (4000 points) distributed on a sphere
- Nexus Core: animated wireframe icosahedron with glow halo
- OrbitControls with damping
- Loading screen with progress animation
- Audio toggle wired up
Fixes#111
Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>
