ffe_deck

The cloud deck of Fire For Effect — the unbroken white floor 140 m below the saddle that fills the valley to the horizon and reads as ground. The vertex stage lifts a flat grid into cumulus tops from a three-octave field of world XZ, so all 64 deck tiles share one continuous surface with no seam. The fragment stage hand-shades it as a scattering medium (wrapped light, a silver forward-scatter rim, blue-violet troughs) off the scene's own directional light, and reads three per-instance hole records to tear the deck open and let the underfire orange up through it.

Per-instance lanes: 0,1,2 = the three nearest holes as (world x, world z, radius, heat); 3 = (film time, ruin, -, -). The material blends as cutout, which is what makes a hole a hole.