lightmap_bake

Bakes a lightmap on the GPU — one thread per lightmap texel. Each thread reads its world position + normal, evaluates the shadowed direct irradiance (every scene light, visibility via a BVH shadow ray), then gathers indirect irradiance by tracing indirectSamples cosine-weighted path chains of up to bounces surface interactions. Every path vertex contributes its emissive plus its albedo (carried on the triangle records by compute.buildBvh) times the shadowed direct light there; a segment that escapes contributes the sky. Direct + indirect accumulate as RGBA into output (A = coverage).

Bindings (see bindings.yaml): output (read_write), texel_positions, texel_normals, bvh_nodes, triangles, lights, params — all array<vec4<f32>>.

Usage: dispatch by identity with compute.dispatch("@builtin::systems.globalIllumination.lightmap_bake", ...) (buffers in bindings order) — it resolves to the shader's stable guid and auto-compiles on first use (no setup).