p_fire — PYRE

Part 9 of the Raising Preseed demo (t = 215–240): a raymarched bonfire raging inside a ring of rune-carved standing stones on open moorland, under a moonlit star field with a milky-way band.

Every surface runs a fyr_* shader (materials in preseed/fire/):

• fyr_sky — night dome: stars, milky way, mottled moon + halo, horizon cloud wisps.
• fyr_ground — moorland terrain (vertex height field, flat inside the circle) with a scorch ring and pulsing coal bed; the flickering fire light is cut by analytic shadows from the eight standing stones, so the circle dances with the flames.
• fyr_rock — faceted granite (Geo.rock meshes) for menhirs and fire-ring boulders; the menhirs carry a carved rune band that the music build charges with ember light (rune_glow).
• fyr_log — charred teepee logs glowing through crust seams.
• fyr_ember — a 240-strong GPU ember swarm (Geo.pointCloud octahedra, vertex-stage spiral flight, zero per-frame CPU).

The flame + smoke column is the part-owned raymarched volume (Vol.spawn fill shader in this module): ridged-noise licks, white-hot core punched by the toms, tip breakup, domain-warped smoke with orange underlight.

The part drives game_t on every material per frame (deterministic director seeks) plus flick, heat, ember_glow, ember_boost and rune_glow from the music analysis.