spineforge

The geometry forge for the Ironspine. A small flat-shaded mesh builder (Forge.builder() → :poly :quad :box :prism :tube :torus → :mesh()) plus the shape recipes the tower is assembled from: vertebra, disc, rung, lip, pipe, bolt, crumble, piton, pitonLens, cable, chain, wreckSlab, seaRib, crownRing, beaconLens, baseDeck, floodMast, floodLens.

Each recipe returns a builder, so a whole vertebra — drum, end flanges, bolt rows, rib spurs, dorsal blade, hull plating, conduit — is one mesh and one draw call rather than forty entities.

Vertex colour carries two things at once: RGB is the surface's own albedo tint (the Forge.TINT table: iron, plate, rust, brass, verdigris, salt, sodium), and ALPHA is the wear mask the wet_iron shader reads, 0 pristine to 1 eaten. That is why one material dresses the entire tower and the geometry decides where it has rotted.

Hardware is modelled in a fixed frame so the placement code can orient it with one call: local +X runs along the route, +Y is up, +Z points out of the wall.