Satellites, end to end: CelesTrak element sets behind the same TTL cache
the weather and the flights use, served as TLEs rather than as positions,
and propagated in the browser with SGP4.
Sending elements is the same trick `flights/plan.ts` plays and it has a
better excuse here — a TLE *is* the closed form, valid for days either
side of its epoch, so one cacheable fetch every six hours replaces a poll
and every viewer agrees about where everything is.
Two things are worth knowing about the shape of it:
- There is no region parameter. An aeroplane at 10,000 m is local and
a satellite at 550 km is above the horizon for a circle two thousand
kilometres across, so one catalogue serves both boards and the client
decides what is above its own horizon. Only the observer is per-city,
which is why `main.ts` shares the elements and rebuilds the catalogue.
- The layer draws on a dome, because it cannot draw anywhere else.
`world.metres(550_000)` is 21,000 scene units against a far plane at
3,000. Azimuth and elevation are real; the radius carries nothing.
Off by default: a clone that started pulling CelesTrak on `npm run dev`
would have volunteered somebody else's bandwidth for its onboarding.
Godmode gets the two dials that point at the sky rather than at the
light — fabricated traffic, which composes with a live ADS-B feed instead
of replacing it, and a switch for the satellite layer with a count beside
it. Both are god-only lies about the inputs, in the manner of the weather
override.
`satellite.js` is the second runtime dependency this package has taken.
Its entry point star-exports an Emscripten build that cannot be shaken
out, so `noWasmPropagator` in the Vite config cuts it: 308 kB of WASM
loader for a bulk propagator nothing calls, against 26 kB for the SGP4
that does the work.
Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
`shots.mjs` renders the product imagery for lumbridgecorp.com/simulate: seven
frames of the running `dist/`, at chapters and times chosen rather than
defaulted, written as WebP into the sibling site checkout together with a
generated manifest that carries each picture's caption and alt text. The pages
there had described a renderer in prose for their whole life without ever
showing one, which is a strange way to sell a renderer.
The captions live next to the camera poses in this repo, not on the site, so
re-aiming a camera cannot leave a caption behind describing the old view. The
manifest emits a `ShotId` union, so a page asking for a picture that has been
renamed fails the site's typecheck instead of rendering a hole.
Along the way: the share cards were never reproducible. `scenekit.ts` eases a
chapter change over about two seconds of scene time, `stage.ts` clamps `dt` to
50 ms a frame, and SwiftShader here draws about three frames a second — so the
flight takes twenty seconds of wall clock and `capture.mjs` waited four. Every
run caught the camera at a different point over the bay, and none of them at
the chapter the key press asked for. Both scripts now open the page with
reduced motion, which is the app's own answer to "somebody clicked a name in a
list": `flyTo` sets the pose outright. `og-tera.png` is regenerated and is
Hayes Valley for the first time. The bytes still differ run to run, because
aircraft are crossing and cloud shadow is drifting; the framing no longer does.
`harness.mjs` is the static server, the SwiftShader flags, the two-hostnames-
one-dist trick and the clock shim, extracted because there are two consumers
now and two copies would have drifted apart while both claimed to photograph
the same app.
Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
Ten agents wrote this in parallel against CONTRACT.md, which exists because the
five design agents before them collided on fifteen blocking points — four files
specified twice with incompatible contents, three separate backends for one box,
and `Environment` exported twice meaning different things.
What landed: a Stage owning only the renderer and the loop, with the city and an
office as two scenes over it. They cannot share one — San Francisco is ~94 m per
scene unit with 3.6x vertical exaggeration and an office is 1 unit = 1 m — and
the city is paused rather than disposed on the way in, because rebuilding its
336,864-point heightfield costs about a second on the way back out.
Offices are data. `src/offices/lumbridge-hq.ts` is fifteen rooms and seventy-six
seats, and it is the file a self-hoster copies. Walls are a segment list with
1-D openings, so doors and windows are holes punched in a wall rather than
placed objects, and the pass that splits a wall around its openings hands the
walk-mode collider its segments for free.
The sun is real. `solar.ts` is a NOAA/Meeus implementation with no imports at
all — not even three.js — so time of day keeps working on a laptop in a field.
Verified against known values: 75.45 degrees at the June solstice in SF, 28.79
at December, sunset at 03:15Z. The first screenshot after wiring it was a black
rectangle, which turned out to be correct: it was midnight in San Francisco.
Presence binds to a seat id and never to a coordinate. The pack knows where
`eng-04` is; who is sitting in it is private data behind an API. Same shape as
the marker rule, one level in.
Two corrections to ARCHITECTURE.md are in here. Containment does not discharge
ODbL — publishing OSM-derived coordinates is Public Use of a Derivative Database
wherever the rows live, so the rule is about the geocoder (US Census, public
domain) and not the storage. And a person at a desk is not a Marker; markers are
geographic.
One contract gap surfaced only in a screenshot: two agents read `height` on a
viewpoint differently, so the establishing shot aimed at empty air fourteen
metres above the roof. It now means what the same field means for a city.
Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
LSE is the third of the three, beside lumbridge-compute and lumbridge-bench: a
3D engine for walkable places. This first commit is the outside of the world —
San Francisco — plus the seams the inside will attach to.
The engine renders a City and a list of Markers and knows nothing else. It does
not know markers are usually companies and it will never learn that "rejected"
is red; that mapping lives in an adapter. Which is what lets one renderer serve
a private map, a public one, and a self-hoster with no Lumbridge account, none
of them a fork of the others.
Three things were designed around the licence rather than discovered after it,
because each one is a promise Apache 2.0 makes that is easy to break by
accident. No trademarks in the repo — logos are fetched at runtime, and
public/logos/ is gitignored. No OpenStreetMap-derived coordinates, which is why
every coastline in cities/sf.ts was traced by hand: Nominatim output is ODbL,
share-alike, and would attach to the whole pack. And no FlightRadar24 client —
their terms forbid scraping and redistribution, so flights are an interface
with a simulator and open community ADS-B behind it.
The privacy constraint and the licence constraint turned out to want the same
thing. Geocoded company positions and pipeline status both stay behind Workie's
API; the open repo holds the city and the renderer. The tempting shortcut —
commit an sf-companies.json — breaks both at once.
Ported out of Workie, where a 3D city engine had no business living. Workie's
/live is deleted rather than deprecated.
Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
karti
Karti Tripathi