moisture_q was a single body constant (derive_moisture_q took only &BodyParams →
80 for every one of 2048 ocean-world districts), so vegetation/terrain/ecotones
were uniform — "nothing to fuzz" (the T-1080 believability bug).
- district_profile.rs: derive_moisture_q is now a body ceiling (hydrosphere+atmosphere)
× per-district gradient — latitude (equator wet → pole dry), elevation (orographic/
rain-shadow), continentality (100 − ocean_fraction_q). Integer/D-010, no new plumbing
(elev_q/ocean_fraction_q/latitude_deg already reach build_district_profile). Mirrors
D-240's temperature model. Coefficients in ClimateConstants + climate_constants.toml
[moisture_gradient] (provisional; Q-123 calibrates). Tuned so a wet body stays mostly
green with drier patches and a frozen body clamps mostly barren. + gradient unit test.
- region_profile.rs: region-tier moisture gets the region-latitude gradient (elevation/
continentality are district-scale).
- Propagates to precipitation_class / vegetation_class / morphology_zone (all read
moisture_q). D-239 §2 amended. Believability golden regenerated.
Probe (Arbour @ yolo): moisture_q distinct 1 → 49 (spread 0 → 48); 5/7 → 6/7 criteria.
Edict (frozen): moisture 0..20 ×21 — gradient within its low ceiling. Remaining fail
(vegetation-present) is the metric dividing by all-sampled incl. water on a 2/3-ocean
world — a Q-123 calibration concern, not a climate defect.
clippy --all-targets -D warnings clean; 1580 lib tests + harnesses pass.
Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
The water zones (OpenOcean/Lake/TidalFlat) fell through to the dry-land AlluvialPlain
fallback, so the sea rendered as dry forested land (the D-245 believability bug).
- voxel.rs: new MorphologyFamily::WaterBody (9th family) + generate_water_body,
dispatched from zone_to_family. Deep open water with a Shallow shoal band on the
district-anchored coast line (wider for shallower bodies); TidalFlat all-Shallow.
Seabed Rock (steep) / Sand (gentle) / Wetland (tidal mud); Vegetation::Barren;
water surface elevation_m = 0; seasonal Ice via derive_cover (frozen seas). Wetland
stays AlluvialPlain (it is land — a marsh, not open water). Integer/D-010. + 4 tests.
- believability.rs: fix a sampling bias in the T-1083 enforcer found while verifying
this — the metrics sampled the first 64 districts in BTreeMap order (a spatial corner,
e.g. all-ocean), which reported a forested world as "0 vegetated". Now a deterministic
seeded spread across the body (matches D-245's "randomly-sampled locations").
- D-239 amended (§5 8→9 families; §6 refined — the 3 water zones now dispatch to
WaterBody). Believability golden regenerated.
Probe (Arbour @ yolo): water-renders-wet 4/64 FAIL → 42/44 PASS; terrain-material
variety 1 → 4 PASS; 3/7 → 5/7 criteria. (Remaining fails — moisture gradient,
vegetation-present — are T-1080.)
clippy --all-targets -D warnings clean; 1579 lib tests + the harness pass.
Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
Promote the throwaway aliveness probe into a committed, repeatable believability
protocol — the instrument that found T-1080/T-1081/T-1082.
- atlas/believability.rs (new): BelievabilityReport (serde) + analyze() computing
CONTRAST (per-field min/max/distinct for moisture/elev/slope/ocean over all
districts; distinct morphology zones / vegetation classes / terrain materials)
and COHERENCE (water-renders-wet, drainage-monotonic, vegetation-present) — never
marginal per-tile counts (the lesson: that called a broken uniform world ALIVE).
evaluate_criteria() = advisory D-245 checks; cascade_for_body()/seed_to_u64()
loader shared by the bin and the harness. Unit tests prove the metric tells a
uniform world (fails) from a varied one (passes) + determinism.
- bin/aliveness_probe.rs: refactored to a thin CLI over the module — prints the
body-level report + advisory D-245 criteria, drops the naive per-tile verdict.
- tests/believability_harness.rs (+ golden): runs the real cascade for Arbour
(temperate/ocean) + Edict (frozen/ice), asserts determinism, golden-snapshots
the reports (regression — updates when T-1080/T-1082 land), advisory criteria
with BELIEVABILITY_STRICT=1 to fail on unmet D-245 criteria. Skips if committed
data absent. x86_64 golden (cascade has f32 warp paths).
Baseline @ believability-v1: Arbour 3/7, Edict 3/7 criteria pass — moisture
gradient, water-renders-wet, drainage all FAIL (T-1080/T-1082); Edict vegetation
0/64 (blank tundra — the frozen 'reads dead' case D-245 targets).
PNG layer maps (ticket item 3) deferred — explicitly optional; the contrast +
coherence metrics are the core enforcer.
clippy --all-targets -D warnings clean; 1575 lib tests + the harness pass.
Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
jpmschweitzerandClaude Opus 4.8