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
Presentation only. No generation file is touched — Topography, TerrainNoise,
IslandFalloff, Pass1Result, TerrainGenConfig and GenerationScale are all unchanged.
Batch naming, fixed in code. The prefix is the AUTHORING TASK number, not a running
counter: 04_review means "the batch task 04 authored", not "the fifth batch". It had
already drifted — tasks 02 and 03 produced 00_smoke through 05_trophy_10240 across
two tasks, so no folder name said which task made what. Now the task number is an
explicit argument to ToolingPaths.BatchRoot(taskNumber, descriptor), which composes
the prefix itself and REFUSES a descriptor that carries its own. All three tools
take it as ISLA_TASK. Verified: ISLA_BATCH=05_foo is refused with a stated reason
and exit 2, and creates no folder.
Also fixed: an exception out of _Ready does not stop Godot — it logs and the process
sits there with no main loop, so a misconfigured run HUNG rather than failing. A
hang looks like slow work, which is worse than a crash. The batch tools now catch,
print what was refused, and exit non-zero.
Grayscale mode: normalize a field to its own [min,max]. This is the one place
per-image normalization is correct — everywhere else anchors are fixed so images
compare, but here the point is to see one field at full contrast. The range is
printed and indexed so a shade reads back to a height. You cannot judge noise
through a palette: a ramp bends the distribution, a hillshade adds shape the data
does not have.
The wide Costa-Rica palette, and the reframing the developer asked for: the pretty
map is the WIDE GRADIENT RENDERED FLAT, and relief is no longer the hero. On raw
pass-1 noise a hillshade has nothing coherent to shade, so it renders fine fractal
bumpiness as fuzz that actively hides the elevation the colour is showing. Strong
hillshade is retained as diagnostic_relief and labelled a dev view — its bumpiness
is exaggerated slope, not extra terrain. Subtle relief is kept for comparison, with
the honest note that it still fuzzes until Phase 2 carves coherent landforms.
Legend: a colour bar with ticks drawn from the palette's own ramp, so it cannot
drift from the map beside it. Ticks are RELATIVE height and the image says NOT
METRES — the conversion is Phase 2's, and labelling it "m" would invent a fact in
the artefact a reader most trusts. Text comes from a 5x7 bitmap font written for
this, specifically so a legend does not drag in the SubViewport capture path.
Stands up the CODE_REPO the rewrite is written into (D-049, D-058). Godot 4.7.2 /
.NET 8 / Godot.NET.Sdk 4.7.2. Nothing is generated, meshed, or ported — this is the
shell and the two data contracts.
Four layers, each with its boundary stated in a directory README:
Core/ math + data only, and engine-free — depends on nothing above it
Server/ authoritative logic (empty this phase)
Client/ rendering (empty this phase)
Tools/ the offline generator — may NOT reference Client (Phase 1 fills it)
Contracts (compiling stubs, no algorithms):
- Column model (D-053): a 2D grid of columns, each a stack of (material, thickness)
runs, any material at any depth. Air is the TOP RUN — there is no air-vs-solid
height branch, and no surface-height accessor exists to reintroduce one. Water is
not a band; it stays an overlay.
- Material schemas (D-054): terrain and building as two append-only registries,
bridged by a recipe seam that is deliberately EMPTY. Identity is a registry key,
never a serialized ordinal. Mesh style is per-ORIGIN and is not a material field.
Rails, so Phase 1 inherits them rather than rediscovering them:
- GenerationScale: MapSize is a parameter, everything derives from it, nothing uses
a raw pixel number. Tightening over the reference — decorrelation offsets are
declared in map widths, not pixels (chat1/00 §4.2).
- ToolingPaths: config/blueprint/output paths all env-overridable, resolved in one
place, so a batch cannot touch the developer's live files.
- FileSafety: the permanent no-deletion rules as throws rather than sentences.
user:// isolation: project name and use_custom_user_dir both pin the runtime dir to
~/.local/share/islaApocalypse-v2/, away from the old prototype's preserved seeds and
batches. Tools/Scenes/UserDirProbe.tscn confirms it rather than assuming it.
