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>
Three things that were built and never connected, connected.
**The weather was already there.** `observe()` has always taken a
`WeatherObservation` and `main.ts` has always passed null, so the cloud,
precipitation, visibility and marine-layer paths in atmosphere.ts had never run
outside a test. The server already shipped NWS, met.no and Open-Meteo, all
configured off. What was actually missing was that a single TERA_ORIGIN_LAT/LNG
served one metro and lied to the other — so weather and traffic are per-region
now, derived from the city's own bounds, and the Bay Area gets its fog while
Long Beach gets its own sky. The route takes ?city= or a validated ?lat=&lng=
and refuses to become an open geocoding proxy for the planet.
**The heightfield moved to a Worker.** 2.3 s of blocked main thread at boot, and
another ~950 ms of point-in-polygon on top of it: the park mask is filled in the
worker now, and block placement samples four corners and only runs the exact
test on a cell that straddles an edge — 8 buildings differ out of 185,036.
createScene is async and takes a Stage as a consequence, and there is a
main-thread fallback because "clone it and it works" has no exception clause.
**Spaces is a chunk you fetch when you reach for the door**, not one everybody
downloads. Same for the godmode tools. The entry chunk is 722 kB rather than
772; three.js is most of what is left and splitting it is a different job.
**Godmode is an instrument panel now** rather than one slider: the date and the
season, not just the hour, so the Meeus moon and the sun's seasonal arc become
visible instead of merely correct; a weather override that says on screen when
it is lying; a frame-time and draw-call readout; and a pose editor that emits a
paste-ready Chapter block, which is the thing that makes adding New York cheap.
Two blockers the review caught:
- Every city switch leaked 8 GPU textures — one of them a 2048x2048 shadow map
— and ~10.5 shader programs, and deleteTexture had never been called once in
the app's lifetime. The renderer was being built per scene; it belongs to the
canvas, for the life of the page.
- An upstream fetch that threw rather than returning null skipped the cache
stamp, so the TTL — the only rate limit on outbound calls — collapsed to one
upstream request per inbound request, and the caller got a 500.
Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
Six agents in parallel, and the two city packs independently reported the same
blocker: `focusRegions` and `coarseFactor` existed on the `City` type and
nothing implemented them. Uniform lattices would have been 2.9M points for
Southern California and 3.7M for the expanded bay. Both packs were unloadable
as written.
`buildAxis` is the answer, and it is honest about its limits: refinement is per
axis, not per rectangle, so a focus region sharpens its whole row *and* its
whole column. Two regions at opposite corners refine nearly everything between
them. Measured, not guessed — the bay went 0.53M points with one region and
1.64M with three, for detail nobody is looking at from a board this wide. One
region each, coarse factor ten, and the builds land at 3.8 s and 2.3 s.
Then three things that were only ever right because San Francisco was the only
city. `maxDistance: 340` and a 170-unit shadow box were constants tuned for a
230-unit board; the bay is 1003 units across and the camera physically could
not retreat far enough to frame it. Fog distances were scene units pinned to
the same assumption. And `minVisibilityM` defaulted to 4.5 km of honest
weather, which over ninety-four kilometres of bay correctly hides three
quarters of it — the night view was a black rectangle for a completely
reasonable reason. All three now derive from the board.
The moon is a real ephemeris and its light is a deliberate lie: 1.15, against a
physical ratio of one to four hundred thousand. What is being reproduced is
what a moonlit night looks like on a screen in a lit room.
The CI gate caught itself, which is the part worth keeping. Port 8431 was
already held by a server from an earlier session, so the boot check polled a
healthy stranger while the process it started died on EADDRINUSE. It now
refuses to run rather than pass.
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