WeatherPP

Presentation and quality contracts for weather in Godot 4.7: quality tiers, the frozen forcing ABI a compiled plant kernel reads, the climate clock, and sea state.

The weather simulation is not here. It lives in the WorldMaker plugin, which owns the world and therefore owns its climate. WeatherPP describes weather for a presenter.

Status

Version 0.3.0. 0.2.0 was a scope reduction: the plugin previously shipped its own weather engine, sampler, wind field, climate profile and grid. Those moved to WorldMaker when EnC's real simulation did, which left this plugin as a second implementation of the same atmosphere. 0.3.0 then gave SeaState the fetch-limited wave model EnC's water actually uses: a growth (wave age) term with build/decay, and a WaveSpectrum that couples each band to the local wind. What remains is what a game actually consumes. See docs/MIGRATION_FROM_ENC.md.

What it provides

WeatherConfig	Quality tiers: edge scaling, relaxation passes, worker caps, cloud display heights
WeatherSample	One tile's weather, and forcing() — the frozen Vector4 axis contract
ClimateCalendar	Ticks per day, year length, axial tilt, season phase, declination
SeaState	Swell growth from wind and exposure, build/decay easing, chop, foam
WaveSpectrum	Wave shape as a pure static function: per-band wind alignment, mesh fade

Install

python3 tools/package_addon.py /path/to/consumer/project

Installs addons/weather_pp/. Runtime use does not require the editor plugin; the dock only reports which version and ABI are installed.

# Quality for the terrain the atmosphere is running on.
var config := WeatherConfig.for_tier(WeatherConfig.QualityTier.HIGH)
var edge := config.effective_edge(terrain_edge)

# The contract a compiled kernel reads. Check the ABI version first.
if WeatherPPManifest.forcing_abi_version() == WeatherSample.FORCING_VERSION:
    var forcing := sample.forcing()   # (temperature_c, rain, snow, evaporation)

# Sea state for a water presenter.
var sea := SeaState.from_wind(weather.wind_speed, weather.wind_direction, tile)
sea.exposure = shelter_factor(tile)          # 0 sheltered cove .. 1 open ocean
sea.advance_toward(fetch_target(tile), dt)   # wave age: build/decay, or omit for open ocean
var y := sea.height(vertex, cells_across, stride, time)

Layout

addons/weather_pp/   the installable plugin
  core/              data contracts (config, sample, calendar, sea state, spectrum)
  runtime/           the manifest reader
docs/                architecture, API, and what moved out of this plugin
scenes/              playground.tscn — a runnable headless demonstration
tests/               standalone SceneTree suites
bench/               standalone benchmarks + committed baseline
tools/               package_addon.py, run_tests.sh, run_bench.sh, compare_bench.py

Verify

godot --headless --path .        # the playground demo, then quits
./tools/run_tests.sh             # 5 suites
./tools/run_bench.sh --compare   # benchmarks against the committed baseline

Everything runs with no game and no world present: the contracts are pure, and the benchmarks construct no grid, no engine and no terrain.

Benchmarks

Case	Median	Notes
sample_forcing_100k	68 ns/op	The per-tile ABI packing a kernel reads.
sea_height_10k	~2.0 µs/op	Per-vertex cost. Worth knowing before evaluating it across a large mesh.
calendar_season_100k	~810 ns/tick	Three calendar queries per tick.
config_resolve_1000	~3.5 µs/op	Allocates a WeatherConfig; do not call it per frame.

Not in this plugin

The weather simulation (WeatherSystem, AtmosphereGrid, WorldTopology) — that is WorldMaker's. Rendering: cloud lobes and the water mesh stay in the game, which also supplies sea exposure and the fetch-limited growth target because only it knows the coastline.

Licence

MIT. See LICENSE.