VibeVoxelProbes Demo v1.3

This Three.js demo is a rapid prototype of "VibeVoxelProbes", a dynamic, voxel-based global illumination approximation, "vibecoded" by Trent "Tront" Sterling and AI assistant (Gemini 2.5 Pro Preview 05-06). It serves as a conceptual testbed for a high-performance lighting system intended for Unity, particularly for VR and other performance-constrained platforms.

Core Concept: "Light Probes on Crack"
The system aims to replace expensive traditional real-time dynamic lighting (per-pixel or per-vertex) with a more performant and scalable solution. It works by baking lighting information (dominant direction, color, and directional coherence/spread) from multiple dynamic light sources into a relatively low-resolution 3D voxel grid. Meshes in the scene then sample this single 3D data structure (conceptually a 3D texture) to determine their lighting. This trades some VRAM (for the voxel data) for significantly increased rendering speed, as the cost per mesh becomes a fixed lookup rather than iterating through many lights.

Advantages Over Traditional Methods:

• Performance & Scalability: Efficiently handles many dynamic lights, ideal for forward rendering.
• Improved Visuals vs. Vertex Lit: Avoids common vertex lighting issues like "long triangle" artifacts and LOD pop-in, while providing spatially consistent lighting.
• Normal Mapping Support: The per-pixel light direction sampled from the grid allows for proper use of normal maps.
• Static Light Optimization: If lights don't move, the voxel grid isn't rebaked, becoming extremely fast.
• Efficient Updates (Future): A Unity version would leverage compute shaders for partial/patched grid updates.

Lighting Model in this Demo:

This prototype focuses on a single dominant light direction (blended weighted average from point lights + a global ambient directional base), an accumulated light color, and a calculated "directional coherence" (spread factor) per voxel. Probe spheres use a Half-Lambert diffuse model (blended with an omni-directional term based on coherence) for soft falloff, combined with a Blinn-Phong specular component for highlights.

Features Demonstrated:

• CPU-based real-time baking (up to 20 dynamic lights).
• Blended dominant light direction, accumulated color, and directional coherence per voxel.
• Visualization of dominant light directions.
• Movable and static "probe spheres" sampling the voxel grid.
• Inverted hull rendering for voxels; surrounding encasing box.
• Dynamically adjustable grid resolution, voxel size, and number of active lights.
• Extensive GUI controls.

This collaborative prototype helps visualize and refine "VibeVoxelProbes" concepts before full-scale Unity development.

Learn more about "Vibecoding" at Tront's Blog.