sub_floor

Polished studio floor surface shader for the substance part. Near-black tiles on the pedestal grid pitch with thin emissive seams (music-driven via seam_glow, fading with distance from the array), brushed micro-roughness variation, and a fresnel-weighted mirror term compositing three analytic reflections over the shared studio_env(): the sphere array (reflected ray marched to the sphere plane, nearest grid sphere intersected and shaded with the same array_albedo() ramp sub_sphere uses), the obelisk's four emissive strip columns (closest-approach glow, following the obelisk's rotation via obelisk_rot), and the cove itself blurred by local roughness.