col_sky

Dusk skydome for the collapse part, rendered on the inside of a large sphere (Geo.inside(Geo.sphere(...))). A smoggy industrial sunset: deep blue zenith over a burnt-orange horizon, streaked smog banks, high cirrus, a low sun disk with halo, a two-ring procedural city-skyline silhouette with sparse lit windows, and faint early stars overhead.

The sun position tracks the scene light (-light_direction), so Lighting.applySetup steers both the visual sun and the shading of every col_* surface at once. col_env here is the environment shared by col_glass and col_steel reflections — keep the copies identical.