Core/Scripts/RegionLabeling.cs is the shared-infra contract, built to the letter: it runs on
the CLASSIFY (raw) field; land is 8-connected, the deliberate complement of water's 4 (a
diagonal isthmus joins; the water either side stays separate); a component is a maximal
8-connected set of land cells; the MAINLAND is the component containing the map centre —
not merely the largest, which a later fragmentation step could flip — with a flagged
fallback to the largest if the centre were ever water (asserted, never needed: oracle m);
every other component is an island; per component id / sizeCells / centroid / hemisphere
(by centroid, one label per island) / isMainland. Ids come from a fixed scan order and are
proven stable across two generations (oracle o, 16.8M cells). It knows nothing about
offshore or stamped. Engine-free, in Core as C++-candidate math; the hemisphere convention
moved there with it, OffshoreAnalysis aliases it.
Tools/Scripts/RegionPass.cs is pass 1c: label, revert, relabel, tag. The island tag
(renamed IsIsland; IslandHemisphere from the component's centroid; Pass1Result.Regions
carries the whole table) is now a CONSEQUENCE of labeling — every non-mainland component.
That is the fix for the chat2/06 overlay, which tagged only what the offshore pass raised:
1063685222 has 11 natural islands including a 94,511-cell detached mass, 20260821 has 19,
all grey in 06's tags.png and all coloured now. The offshore pass itself is untouched; its
internal Tag stays for its own guards and is no longer exported.
The speck revert (TerrainGenConfig.SpeckRevert / MinLandComponentFrac) lowers every
non-mainland component below the threshold to the mean of its ring of adjacent sea cells,
held strictly below sea. Origin-blind: a natural nub goes the same way as an offshore dot
(6 natural components / 273 cells on the bare 1063685222 field at threshold_mid — reported
as a3r, informational). Lower-only and component-only are asserted cell by cell in the
pass and re-proven on the finished fields by oracle n (mainland bit-identical filter OFF
vs ON; every changed cell in a sub-threshold island, lowered below sea); the mainland is
never a candidate and its size is asserted unchanged across the revert. A reverted
offshore island leaves its submerged skirt as a shoal — not this component, by the rule.
Classify/render consistency is by construction (pass 1, curve identity at sea) and
asserted by oracle k. Deliberately OFF in the bare TerrainGenConfig for the reason the
shelf and islets are: the raw field has natural specks, so default-ON would move the
calibration pool and every regression dump; the batch turns it on.
Thresholds swept on 8 seeds at 4096 (1e-5 / 3e-5 / 1e-4 of the map = 168 / 503 / 1,678
cells): low removes 0–6 nubs per seed, mid (the config default, equal to the offshore
guard) 2–11, high 26–36 — most of the offshore islands, the "fewer, bigger" bookend. The
count/size table carries natural / pre / post counts per hemisphere, min/median/mean/max
and a log-spaced size histogram — the instrument for the southern-stretch step.
Oracle, all passing: a1, a3, a4 (8192, 67M cells) with labeling ON + revert OFF; a6 NEW —
labeling ON + revert OFF on the 06 preset bit-identical to the 06 batch's render field
(labeling is pure analysis); j0; m, n, o, i, j, k, l, b per field. Batch:
BatchRoot(7, "region_labeling") — exactly 4 plates (three thresholds on 1063685222,
threshold_mid on 20260821, the table's most-natural-islands seed), each with grayscale /
.f32 / relief / the labeled-regions overlay / the tag overlay, plus count_size_table.md/.csv.
Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_013EY3ZTF6NwzF8ukBHQXSK7
Stage 1 fills the IslandFalloff.cs stub from the reference, verbatim: the coast shelf
(below-sea only, depth-preserving, held strictly below sea by MathF.BitDecrement — the
clamp that makes "cannot move the waterline" exact rather than statistical) and the islet
layer (OffshoreBlob, CalibrateThreshold against the field's ACTUAL distribution, the
OffshoreZoneWeight moat + pre-Trench-falloff test). Both run as pass 1b — OffshorePass, a
second sweep over the finished pass-1 arrays with the same per-pixel arithmetic in the
same order — and HMaxSeed is retaken AFTER them, as the reference did. That closes
chat2/00 Drift §2. The value did not move on any of 15 runs; the order is now right by
construction and oracle (l) prints it every time.
Stage 2 is the reshape, OffshoreSettings.Hybrid(): a seeded floor of ≥2 N / ≥4 S islands
placed by a PCG32 off the world seed — min-separated, clear of ALL existing land by a gap
so each stamp is its own connected component by construction, fully inside the zone so
the moat and falloff protections gate the floor exactly as they gate the organic layer —
plus the noise layer on top, smaller (freq 16), lower (24 m pre-curve, which the
preserved toe squashes to ~5 m and keeps there across curve tweaks), flatter (core 0.25),
crisper (edge sharpness 2.5, stamp rim jittered so it is rigid without being a compass
disc), south-weighted (0.007 N / 0.012 S, blended across the midline), corners allowed
(trench mask 0.90→0.97). Every lifted cell is tagged with its hemisphere — NORTH is rows
[0, N/2), y runs south, read off the spine's southern fade and the southern sinker, not
invented — and carried through Pass1Result → Pass2Result for a consumer that does not
exist yet.
Two things the probes taught, both now in the code: the first organic densities produced
183 blobs of which 174 were noise debris (a six-config sweep fixed that), and the
reference's lerp-to-crest leaves shallow humps across the seabed wherever a blob fails to
surface (a guard reverts them outside any surviving island's skirt; specks by component
membership, bumps by location). The faithful control keeps both, because it is the
reference — its islets measure min 1 cell, median 28.
Oracle, all hard checks passing: floor met on every hybrid seed (N 2–4, S 9–16); zero
land bridges; every offshore-OFF land cell bit-identical with offshore ON; tag ↔ coastline
consistent in both fields; curve-off still bit-identical to Phase 1's dump and
continuous_restored to task 03's. Both gates default OFF, deliberately: flipping them is
the act that retires the Phase-1 regression dumps, and that belongs in a task that
re-baselines the oracles.
The faithful control on seed 8675309 produced one north island. That is the gap the
floor exists to close.
Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01DCWNaDZPfTiAy3meGNGgqt
rev 3 of the curve redesign. The developer's verdict on the 01 baseline was that the
LOWLANDS ARE GOOD; the fault is the terracing above them. So this adds a second curve
mode that preserves the low plain bit-for-bit and replaces everything above the flood
line with one smooth monotone climb.
Core/ContinuousCurve — piecewise, and the pieces have different loyalties:
- at/below sea: identity, as ever.
- above sea to K2: DELEGATES to HeightCurve's own toe+red branches. Not "equivalent" —
the same code path, so the same floats. Oracle (d) holds it to that.
- above the ceiling: a Fritsch-Carlson (PCHIP) monotone spline to the 420 m cap,
C1-joined to the red band's exit slope. Monotone by construction for any ordered
control points, which retires the 24-corner sweep; a 10k strict-increase sample runs
per seed anyway, because "cannot fail" is worth a millisecond.
- Build() REFUSES rather than degrades: a ceiling near the old bench, a drama that folds
the summit under its own onset, control-point secants that are not strictly increasing
(the no-magnet rule, enforced rather than hoped for).
Only BENCH_*/PLATEAU_* are dropped. SEA/ORANGE_CEIL/RED_CEIL survive because they are
the storm-ladder FLOOD TIERS and they live inside the preserved lowland; PEAK_CAP and
the per-seed spikeMax normalization survive as the summit.
Shelf detail is forced off in continuous mode: the flat benches it de-slabbed no longer
exist, and painting noise on the climb now would pre-judge what erosion should carve.
Oracle, all hard checks passing:
- (a1) curve off is bit-identical to Phase 1's dump.
- (a2) staircase mode is bit-identical to TASK 01's dump — the control is provably the
control, not a re-derivation. (CurveBaselineTool is pinned to Staircase so the config
default moving to Continuous cannot drift it.)
- (d) lowlands bit-identical to the staircase over 3.6M cells, every continuous variant,
both seeds. The lifted_WRONG bookend fails it on 1.6M cells, as intended.
- (f) sea identity per CELL, not per count, including 67M cells at 8192.
The finding, measured and recorded in the batch scratch: the massif SHRANK. Land above
100 m goes 14.9% -> 4.8%, above 220 m 4.5% -> 0.6%. A feather sweep to the practical
floor recovers ~1.3 points, so this is structural, not a tuning miss: the staircase's
highland area was an artifact of the bench and plateau acting as magnets, and a curve
with no magnets preserves the raw distribution's bottom-heavy shape. "No terraces" and
"the same land up high" are not both available from curve work alone.
Exploration batch, not convergence. A tuning pass follows once a direction is picked.
Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01DCWNaDZPfTiAy3meGNGgqt
Ports the reference's v5 height curve and shelf-detail passes onto Phase 1's shape
and re-calibrates them against this repo's actual pass-1 distribution. This is the
BASELINE the reshape gets judged against, not the reshape.
Core (engine-free, D-060):
- WorldScale — THE vertical yardstick. One metres/raw number (251), replacing the
prototype's three duplicate M_PER_UNIT constants and ~20 bare literals. The
chunk-height coupling it had there is recorded as a DEFERRED vault decision, not
inherited. RawFromMetres divides, matching the reference bit-for-bit.
- HeightCurve — the 7 bands, the frozen corner-fix blends, the per-seed spike
normalization, the 24-corner monotonicity sweep that throws and refuses.
Identity at and below sea, which everything downstream rests on.
- CurveKnots / CurveAnchors — input knots (measured percentiles) and output anchors
(storm ladder) split apart and both made parameters, so the anchors are A/B-able
without editing source. The reference's shipped knots are kept beside the measured
ones as the fidelity yardstick.
- TerrainDetailPass — micro-relief skin plus the shelf-edge KNOT warp (which slides
K3/K4/K5, not height — that is what keeps monotonicity structural). The crater
exclusion is ported and inert until the carve lands.
Tools:
- Shaping — pass 2a, producing the two height fields. classify is bit-for-bit the
raw pass-1 field; render is curved and detailed. Aliased when the curve is off,
as the reference did. Pass1Result is left immutable so the oracle can compare.
- LandHistogram — the calibration engine AND the diagnostic. The reference shipped
six knot literals and threw the measuring instrument away; this rebuilds it.
- ShapingOracle + CurveBaselineTool — four automatic checks before anything is
looked at, and the batch that runs them.
Measured, not assumed:
- Knots re-measured over a 6-seed / 12.8M-sample pool. They differ from the
reference's by at most 5.6 m of world height, against a 44.7 m per-seed spread —
the pass-1 port is faithful.
- Oracle all pass, including pass 1 bit-identical to Phase 1's own .f32 dump.
- Band shares land on 60/13/10/5/8/3/1 to 0.00 pp.
- Knots hold across map size: the 8K delta (5.8 m) sits inside seed noise.
The finding the histograms deliver: 83% of land ends below 100 m and 96% below
220 m, with the median column at 13 m. That is the share targets doing exactly what
they say, not a bug — and it is the developer's call, which is why nothing here
reshapes it and the palette was deliberately left mis-fitted rather than recalibrated
to disguise it.
Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01DCWNaDZPfTiAy3meGNGgqt
