carrington.light.rig

Every source of light in Carrington Night, and every property of the medium it travels through. One module, one function of film time.

What it owns

The one idea

AUR_W(t) — how much of the ground's light comes from the sky — is the film's arc as a single number. It runs 0.03 → 1.00 and it drives the ambient colour, the sun's tint, the fog's colour and in-scatter, the sky's zenith, the environment lighting and the aurora fills together. Everything warms down and greens up on one curve rather than on six.

Things learned here that will bite the next person

• HeightFog has a color field and the package readme's field table does not list it. It defaults to (0.62, 0.68, 0.78) — a daylight grey — which turns the entire far field of a night scene into a white band along the horizon. fog.get() reports it; the docs do not. Pin it.
• EnvironmentLighting re-pushes its own fields to the ibl module EVERY frame, not on change, so ibl.set{...} from content is overwritten before it reaches a pixel. Its siblings (HeightFog, AmbientOcclusion, ScreenSpaceReflections) push only when their signature changes, so a module set on those does stick. Drive EnvironmentLighting through the component.
• component.add on an entity that already carries the component changes nothing, and a scene persists whatever was last poked into it. pin() in this module adds if missing and then always writes every field, so the rig is the same rig on every boot rather than inheriting a stranger's tuning.
• A hot reload drops the module's upvalues and stage.boot()'s build() runs once, so resolve() re-finds every entity at the top of update(). Without it, editing this file while the film runs silently stops the rig instead of changing the frame.
• The film is metered dark on purpose. targetGrey = 0.075 and an EV range of about a stop each way. Given three stops of authority the meter finds them in an empty snow plain and undoes the night; a stop is enough to protect the practicals and to make the detonation read as an overload.