The seeded floor from chat2/05 — FloorNorth/FloorSouth, the PCG32 placement, StampWeight,
StampRadiusFrac/StampCoreFrac/StampEdgeJitter, the centre separation and land gap, the
floor self-check and oracle (h), the centre rings on the tag overlay — is reverted out
whole, as a forward commit. It looked stamped. It is one checkout away at 3b96e06. What
remains is ONE island mechanism: the organic noise-field layer, with chat2/05 stage 2's
shape untouched (freq 16, crest 24 m pre-curve, core 0.25, sharpness 2.5, corners on,
moat + falloff test + outer bound unmoved), now OffshoreSettings.Organic(). The count per
hemisphere is a statistical outcome of the tuning, read off a table, never guaranteed.
The south was measured before anything moved (OffshoreDiagnosis, over task 01's pool at
2048): the premise that the south generates fewer islands is not what the field says.
The NORTH has 1.75x less island-eligible ocean (56 % of its ocean is zone vs 69 %; 233
zone rows per column vs 407) and under half the island candidates (1,183 over-threshold
peaks in zone vs 2,422). Per cell the south is richer too (484 vs 414 candidates per
Mcell). The gate that loses candidates is the moat in the north and the falloff test in
the south — the bulging south coast pushes the 0.72 contour out — but neither binds
enough to suppress it. So the fix is density, and the binding constraint for "a couple
north, consistently" is the north.
The knobs: Density (the main one, the calibration quantile) and SouthWeight (south density
= Density x weight — applied to the quantile, so a south island looks exactly like a north
one; there are just more). Three levels batched on 12 seeds at 4096, SouthWeight 1.25:
0.016 N 2/4.4/10 S 8/13.8/21 (every seed clears N >= 2, S >= 3, but N's minimum IS 2),
0.022 N 3/6.3/12 S 15/19.9/29 (the preset — the first level whose north minimum sits
comfortably above the target), 0.030 N 3/7.8/15 S 19/25.2/33 (the too-many bookend). The
south weight is the developer's stated preference, not a fix; the SouthWeight 1.0 tables
(S 6/10.9/16 at 0.022) are in the batch's scratch/ for the comparison.
The guards, so more density does not buy slop, each a revert by component membership:
specks (< 3e-5 of the map's area, ~500 cells at 4096 — 70-100 per field at these
densities, the noise caps the reference also surfaced), clusters (the smaller of two
islands whose shores are within 0.8 % of the map width — 0-7 per field), blobs (> 6e-4 —
never bit). And the reference's submerged humps, now attributed by HUMP rather than by
bounding box: the first 4096 plate probe showed hollow ghost rings beside islands — a
guard-dropped island's cap went back to seabed but its rim survived inside its
neighbour's bbox keep-region. A hump (one connected raised region) now stays only if it
holds a kept island, and a dropped island's own cap goes even inside a kept hump.
Oracle, all passing: a1 (Phase-1 dump), a3 (task-03 dump), a4 NEW — offshore OFF at 8192
bit-identical to the terrain-curve-v1 tag's own 04 gallery dump over 67,108,864 cells —
j0 shelf inert on land, and per field moat / mainland unmoved / tag-coastline / HMaxSeed
(unchanged, 1.289169) / classify on all 36 table fields and 4 plates. Batch:
BatchRoot(6, "offshore_organic_tune") — exactly 4 plates (three densities on 1063685222,
density_mid on 424242, the table's sparsest south) + count_table.md/.csv + diagnosis.md.
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
Ports MapGenerator.GenerateTopography's pass-1 loop (reference ~:553-619 at tag
pre-rewrite-reference / ab78883) into Tools/. Working code and its tuned constants
carried over verbatim, read from source rather than re-derived from a design
summary (D-050). Six elements, in the reference's execution order — the order is
load-bearing: the sinker lands before the Pow (superlinear), the Trench after it
(a raw additive wall), preTrenchFalloff captured between them.
The fractal config is now PINNED. The reference set only NoiseType/Seed/Frequency,
so the island's entire fractal character was Godot 4.7.1 constructor defaults that
nothing recorded. Measured on 4.7.2 (NoiseDefaultsProbe): Fbm / 5 / 0.5 / 2.0 / 0.0
— identical to the 4.7.1 values, so pinning reproduces the look with no delta. The
terrain no longer depends on an engine default, and the probe makes a future drift
visible instead of silent.
Two deliberate departures from the reference's literals, both flagged in-code:
- the latitude noise offset is expressed in map widths, not the reference's raw
+1000 px, so a resize no longer samples a different slice of the noise field
(chat1/00 §4.2). Pinned to 1000/8192 so the 8K realization is unchanged.
- the `if (temperature < 0.65f)` spine gate is dropped as the provable no-op it
is — southernFade already reaches exactly 0 at 0.65. Bit-identical.
The reference's "temperature" is ported as a latitude field and deliberately NOT
named temperature: it is stage-1-local input to terrain geometry, and climate is
stage 3 (D-049 §2, D-056). The ±0.1 wobble is kept — it is what stops the spine's
southern terminus being a ruler-straight line.
Deferred to Phase 2 with the seam open: coast shelf and offshore islets (below-sea,
judged once water renders). Pass1Result exposes PreTrenchFalloff at their exact
consumption point, plus HMaxSeed for the seed-dependent curve.
Render is a direct Godot.Image, not the SubViewport capture path — that machinery
exists to composite vector overlays and is why --headless hangs; Phase 1 has none.
Hypsometric above 0.15, bathymetric below, fixed ramp anchors so seeds and ablation
rungs are comparable. No biome words anywhere.
Verified: land fraction 51.5% identical at 1024, 2048 and 10240 — the scaling
discipline holds across a 10x resize. Full-size 10240 pass: 36.3 s.
No curve, erosion, rivers, water, crater, biomes, roads, or mesher.
