German KhokhlovandClaude Opus 5.5
e8fd1f2d01
Away from the galactic plane the ESO panorama keeps a mottled glow of unresolved stars and dust. With the black level at the darkest quarter of the sky and a hard cut, it showed as grey clouds with black holes around the globe. The black level now sits at the median sky and eases in with a soft knee on luminance, keeping each pixel's hue: high galactic latitudes are black, the band keeps its glow. Faces shrink from 247 to 85 KB. The changelog fragment also notes the anime fade and the new asset weight. Co-Authored-By: Claude Opus 5.5 <[email protected]>
3.1 KiB
Sky background
The space behind the globe (src/sky/starrySky.js): catalogue stars drawn as
sharp point sprites over a soft Milky Way cube map. It replaces Cesium's
default Tycho-2 sky box, whose six 1024² JPEGs stretch 3–6× around the
whole-globe view and show compression blocks.
| File | Content | Size |
|---|---|---|
bright_stars.json |
9,096 stars: J2000 RA/Dec, V magnitude, B−V | 235 KB |
milkyway_{px,nx,py,ny,pz,nz}.webp |
Milky Way glow, six 1024² cube faces, no stars | 85 KB |
Stars — Yale Bright Star Catalogue
Source: Yale Bright Star Catalogue, 5th Revised Edition (Hoffleit &
Warren 1991), CDS VizieR catalogue
V/50, file
https://cdsarc.cds.unistra.fr/ftp/V/50/catalog.gz (sha256
3dc44b1e90be8fbe5bcc7656032560f51275f985c7e3f783c9028e1838ec7bed, fetched
2026-10-19).
License: public domain (Yale University Observatory / NASA Astronomical Data Center). CDS asks for an acknowledgement; the in-app "Data attribution" popover carries it.
Build: node scripts/build-bright-stars.mjs [catalog.gz] — every record
with a J2000 position (14 novae and non-stellar entries dropped), RA/Dec
rounded to 0.001°, magnitudes to 0.01. The renderer maps magnitude to sprite
width and opacity and B−V to a desaturated black-body colour
(src/sky/stars.js).
Milky Way — ESO/S. Brunier
Source: "The Milky Way panorama", ESO image
eso0932a, full-size original
https://cdn.eso.org/images/original/eso0932a.tif (6000×3000 sRGB TIFF, sha256
10f209ab83e1fd89e7fa1ed70277ffc6ed19c43549f04ec637c6806d98aff035, fetched
2026-10-19). Plate carrée in galactic coordinates, centred on the Galactic
Centre.
License: CC BY 4.0 (https://www.eso.org/public/outreach/copyright/). Credit: ESO/S. Brunier.
Changes made (CC BY 4.0 asks for them to be stated): resampled to
4096×2048, stars removed with a 7×7 morphological opening, two planets
(Jupiter, by position) painted over with the median of the surrounding sky,
blurred (σ = 0.4°), reprojected from galactic coordinates to ICRF cube faces,
black level set at the median sky with a soft knee (the faint glow away
from the galactic plane fades to black), gamma-encoded and saved as
WebP. Build:
node scripts/build-milky-way.mjs <eso0932a.tif>.
The panorama is a photographic mosaic, not an astrometric map: bright stars sit up to ~2° from their catalogue positions. That is invisible in a glow blurred this much, and every sharp star on screen comes from the catalogue.
The NASA SVS "Deep Star Maps 2020" Milky Way layer was considered and not used: it is derived from Gaia DR2, which ESA distributes under CC BY-NC 3.0 IGO with prior authorization required for commercial use.
Frame
Both layers are in ICRF/J2000. The cube faces use the standard WebGL face
layout with +X towards the March equinox and +Z towards the north celestial
pole, uploaded without flipY. At runtime one rotation —
Transforms.computeIcrfToFixedMatrix at the scene clock — turns both into
Earth-fixed coordinates.