Go anywhere — a square, a village, a vineyard, a valley, a mountain ridge — and
see what it is like to stand there. Drag two sliders, time of day and day of
year, and real shadows move across the same 3D world Google Earth draws; switch
on a layer and the ground shows which surfaces bake on a clear morning and stay
warm on a clear night, how the air sits street by street, how the wind threads
between the buildings. Hour by hour, season by season. No build step, no
server: a folder of static files that runs on GitHub Pages.
Sunrise to sunset over the Colosseum — try
it live. The ring is a compass card lying on the ground, the glowing arc is the sun's track
for that day, and the beam arrives from the sun's direction into the studied point.
What it does
- Google Photorealistic 3D Tiles as the world, via Cesium ion — real
buildings, terrain and trees, shadows cast by the actual mesh.
- Two sliders: time of day (sunrise→sunset, or a full 24 h) and day of
year, plus a date picker and a playback that sweeps the span in about half a
minute.
- Sun path overlay: a graduated compass card on the ground, the day's arc,
sunrise/sunset markers, live azimuth and elevation, and the shadow direction.
- Local wall clock at the place you are looking at, DST included.
- Sun-hours probe (ANALYZE tab): ray-casts against the loaded geometry to
estimate hours of direct sun at the pin.
- Layers, by theme — switched on in the rail, read at the pin in the
ANALYZE tab, with their legend on the map — from products precomputed by
pipeline/ over Europe and growing:
- Heat: the surface temperature of roofs, streets, fields and rock by
month, on a clear morning (Landsat, 90 m) and a clear night
(ECOSTRESS from the Space Station, 70 m) — when a city gives back the
day's heat; and the mornings of earlier decades back to 1984 (Landsat 5
and 7) on the year slider;
- Air: the five-year habit of NO₂, PM10, PM2.5 and ozone by month and
hour, street by street at 50 m; before 2020, that month of that year
since 2003 from the CAMS global reanalysis, in its 80 km blocks;
- Noise: road traffic as a day–evening–night level (Lden) at 10 m,
modelled from the class of every OpenStreetMap road and screened by the
buildings, calibrated on Berlin's official END noise map and checked on
Hamburg's — within one 5 dB band on nine cells in ten;
- Pollen: grass, birch, alder, olive, mugwort and ragweed on the
selected day, from the CAMS forecast or archive, each on its own bands;
- Light: how bright the night sky is overhead, in the magnitudes per
square arcsecond a Sky Quality Meter reads, with its Bortle class and what
is left of the Milky Way, year by year since 1992 on the year slider —
each year's VIIRS night lights (NASA Black Marble; the older DMSP
satellites before 2012, chained to VIIRS) spread by a glow kernel fitted on the World Atlas of Artificial
Night Sky Brightness, within a factor of 1.5 of it on 94 cells in 100
where it was never fitted;
- Growth: what was built after the year on the slider, tinted over the
3D city of today — the JRC's Global Human Settlement Layer, the built-up
share of every 90 m by five-year epoch from 1975 to 2020;
- Wind: the 10 m wind as drifting particles, threaded between the
buildings where a tile carries them;
- and the selected day's weather and air, read at the pin.
- Shareable links that restore the exact view, date and time.
- Works on a phone: the panel becomes a bottom sheet, the camera answers
to fingers, and the shadow and tile budgets start lower.
Out of scope: drawing, placing objects, editing the map.
How to use it
The same four things the in-app guide walks through — press ? in the
app to read it there, with the clips playing at full size.
Time of day
The upper slider is the hour. Drag it and the sun walks its arc while every
shadow in the mesh swings with it — the clock, the compass bearing and the
elevation readout all follow. The ends of the slider are that day's sunrise and
sunset, unless you ask for the full 24 hours in Settings.
Time of year
The lower slider is the day of the year, and it is the one that answers the
questions worth asking. Hold the hour still and sweep it: the same balcony that
takes full sun in June can sit in shadow all morning in December, because the
sun rises further south and never climbs as high.
Putting the point somewhere exact
The studied point follows the middle of the view while the padlock is open,
which is what you want while you are still looking around. Close the padlock and
it stays put — and then you can pick it up and drop it exactly where you mean,
on a doorway, a terrace, a particular window.
How many hours of sun
The ANALYZE tab ray-casts against the buildings actually around the point and
counts the hours of direct sun it gets on the selected day, sampling every ten
minutes. It can only test geometry that is currently loaded, so zoom in
until the surroundings are sharp before you trust the number.
This is the beginning of the README. Read the rest at the original. Read the full README ↗
