deadlight.sub.rig

The submersible Nautile, built out of primitives, plus the five emitters it puts into the water.

local Rig = require("deadlight.sub.rig")
local h = Rig.build()   -- idempotent: an existing Nautile is taken away first

build() returns the handles the driver writes to: the root, the three thruster hubs, the three lamp pivots, the beacon, the four arm joints, and the five particle systems (beamPort, beamStbd, beamSpot, wash, ballast).

The vehicle's local frame

-Z is the way it faces — the same convention the wreck's bow uses and the one Transform.quatFromBasis calls forward. +Y is up through the sail, +X is starboard. The hull is 8.2 m long, 2.9 m across the fairing and 3.6 m from the skids to the beacon, which is the envelope the shot list is framed against: shot 3 puts the camera 1.7 m to port of the root, just outside the skin. The landing gear sits 1.1 m under the origin, because Film.SUB_PATH puts the origin 1.1 m off the silt in the debris field.

Materials

Nine .material assets under deadlight/sub/materials/, authored by build() with overwrite = true. They are referenced by their FULL identity (deadlight.sub.materials.dl_sub_foam): a bare leaf that also exists elsewhere in the world is ambiguous, and a Model handed the ambiguous name keeps the raw string unresolved and renders untextured.

On the pbr shader emissive is the glow COLOUR and emissive_intensity is how hard it glows. There is no emissive_color.

The lamps

face = "Back" on every SpotLight — that is the lamp's local -Z, the direction the vehicle is aimed along. "Front" is +Z and shines out of the stern (#8632).

Each lamp carries a beam cone: a dense additive emitter firing along the lamp's own axis, its particles widening and dimming down the cone. The engine's participating medium reports active and never dispatches (#7760), so the beam is the suspended matter drawn rather than a fog march — which also means the specks in it drift, and a marched medium's never would.

The emitters are bare particles.create calls with autoUpdate = false: the clock belongs to the film, and SubRig steps each of them by exactly Film.DT per film frame.