# wormBody The animal's geometry. Every piece of the sandworm is a runtime mesh built here and uploaded once: the carapace plates the body is made of, the head, the counter-rotating maw rings, the lit gullet behind them, the tail, and the sand ridge that rides above the buried body. Everything is built at unit radius around the local +Z axis, so the caller scales a piece to whatever size that part of the animal is. The head is the exception: it is built in its own real proportion — radius 1 at the neck, 3.4 long — and scaled uniformly, which is what lets the maw rings and the gullet hang off it as children in the head mesh's own units. `M.loft` is the shared builder: a profile function gives the radius and z of each ring, a shape function gives the extra radius at an angle. The plates, the head, the gullet and the tail are all a few lines of those two. The plates carry UVs the `chitin` shader reads as (angle around, distance along) and tangents that run around the circumference, which is the axis its anisotropic stretch is taken on. `M.plate(spines)` returns a plain plate, one with a raised dorsal keel, or one with a keel and a lateral spike either side — every few segments takes the heavier variant, so the silhouette against the sky has a rhythm without costing another entity. `M.mound` is one slice of the furrow, and it is a single sheet rather than a closed prism: the flanks run out and dive under the ground instead of dropping to a vertical wall, so there is no face that can catch the light the wrong way at a grazing angle — which is exactly the angle the film watches the furrow from.

# film <!-- zero:scaffolded-readme --> <!-- Replace the line below with what this module provides and who consumes it, then delete both comment lines. --> TODO: describe this module.

# worm The animal's route and its choreography, as pure maths. It spawns nothing and reads no entity, so any slice may require it to ask where the animal is. `M.cp` is a Catmull-Rom through the whole 181 seconds — in from the north-west deep under the dune sea, shallow enough to raise a ridge as it crosses the pan, a slow hook under the rig, then straight up out of the ground at the breach point, over in a two-hundred-metre arc, and back in at the impact point. It is sampled once into an arc-length table, so `M.at(u)` is the point `u` metres along it. `M.headU(t)` says how far along the route the head is at film time `t`, interpolated with a monotone cubic through keys pinned to `film.mark.*` — move a beat there and the animal moves with it. Every part of the body is then a function of one number: a segment `s` metres behind the head sits at `M.at(headU(t) - s)`, wearing the radius `M.radiusAt` gives it. Nothing accumulates and nothing integrates, so the film is the same on every run. `M.frame(u, t, radius)` adds the animal's own motion to the rail — a travelling wave that runs the length of the body, wider in the air than in the ground — and returns the world position with the three axes that orient a piece there. Two calls answer questions other slices ask: `M.head(t)` for where the head is and how far out of the ground it has come, and `M.groundTrack(t, back)` for where on the pan the buried body is running and how close under the surface it is.

# filmClock <!-- zero:scaffolded-readme --> <!-- Replace the line below with what this module provides and who consumes it, then delete both comment lines. --> TODO: describe this module.