lum_sky_mat

Pre-dawn skydome material for the lumen opener (preseed/parts/p1_lumen). Carries the shared asc_sky gradient/sun/stars shader on the inside of an inverted sphere: deep indigo zenith, dusty violet mid-band, pale gold horizon, and a tight HDR sun disc that sits behind the westwork's central slit. The night setting keeps a handful of stars alive near the zenith so the oculus shot reads as the last of the night, while the horizon already burns.

The part drives game_t (cirrus drift) and exposure (the end-of-part swell into the drop) per frame; everything else is authored here.