Task 17's hard 1.2 x CraterRadius cutoff left a visible un-eroded disc with a hard
edge. Measured (radius dump, seed 1280587109): the carve writes only inside 0.80 x
(640 px) and its displacement is EXACTLY 0 beyond that, so the 640-960 px annulus
was 620,811 LAND cells of ordinary terrain held smooth for no geometric reason.
That annulus is now eroded — 98% of those cells are touched.
The protected core is the carve's own extent (CraterErosionCore, 0.80 x).
CraterErosionMode selects the transition: "full" applies full strength at the core
boundary (older-crater look), "feather" ramps 0->full out to CraterErosionFeather
(1.05 x, mirroring the detail pass) for a younger-crater look with no seam.
Implemented as a WEIGHT that scales carve and deposit amounts, not a skip, which is
what makes feather a one-liner. Default "feather" pending the gate.
Core = the carve radius is load-bearing, not tidy: the carve runs AFTER erosion and
scales height toward the sea target, so it amplifies any erosion delta inside its
radius. Measured at a 0.50 core: 79 cells newly below the rendered sea and 113,310
below-sea cells disturbed — the in-pass flood guard cannot see this because it
measures before the carve. At 0.80 the two passes touch disjoint cells and the
guarantee is exact again (0/0/0). A narrower core also reclaims nothing extra, since
the over-protected annulus lies entirely outside the carve. MapGenerator now owns
CRATER_CARVE_FACTOR as the single source of that 0.80 and warns loudly if the
configured core is narrower.
Verified both modes, seed 1280587109: 1_biomes/0_water md5-identical to erosion-OFF,
BIOM/WBID bitwise equal, 0 newly below/above sea, 0 below-sea cells modified, 0
cells modified inside the core, island top 457.65 m unchanged, isotropy 1.005/1.007.
Bay-to-ocean connection demonstrated explicitly by flood fill through rendered
water to the map's north border (2,122,935 cells), not merely argued from the sea
clamp.
EROS body version -> 3: craterExclFactor replaced by craterCoreFactor +
craterFeatherFactor + craterMode. Round-trip harness PASS with a real v3 payload.
Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
Deposition now spreads over the same cone brush as carving, and the per-cell
erosion ledger becomes a signed NET displacement ledger, so both caps are
measured from the height the pass found. Brush-spreading alone cut the spike
15.49 -> 6.12 m at task-17 dials, but NOT at hierarchy dials (long paths carry
far more sediment; a loaded droplet meeting a rise dumps min(rise, load) at
once -> 25.5 m). So deposition also gets governor 4, ErosionDepositCap
(default 6 m, <= 0 = unbounded), asserted on exit like the carve cap.
Dial defaults retuned for a drainage HIERARCHY: 250k droplets x 384 steps at
inertia 0.35 / evaporation 0.004, erode 0.12, carve cap 15 m. Diagnosis was
that lifetime 48 let a droplet travel at most 48 px on a ~3000 px island
radius, so paths could not overlap into trunks: the deepest task-17 features
were 43x36 px patches. Now 177 channel systems of 200+ cells at the 3 m
threshold, top one 204x279 px with 14 tributary tips; cells past 5 m up 8.6x
(4,948 -> 42,385) while the fine rills are retained. Verified descending, not
contour-locked: 0/155 components have drop/extent < 0.12 (median 1.13).
EROS body version -> 2 (deposit cap inserted after the carve cap); v1 payloads
are skipped whole by the existing rule. HydraulicErosion.VERSION now reads
BlueprintFormat.EROS_VERSION instead of restating it — the local copy had
already drifted and stamped a v2 body as v1, which readers decode with every
float shifted by one field.
Oracle green on both seeds (1280587109, 1512575962): 1_biomes/0_water
md5-identical erosion-ON vs OFF, BIOM/WBID bitwise equal. Flood guard 0 new
water px, 0 below-sea cells touched, crater zone untouched, island top
unchanged, carve field isotropic to 1.4% across the folded 45deg period.
Erosion pass 34 s at these dials.
Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
Erosion: "off"|"v1" gate (default off, pending the developer's gate). Output-only:
applied to the render map after detail, before the crater carve; the classify path
reads pre-erosion heights, so biomes/water stay byte-identical (verified: OFF run
bit-identical to the task-14 reference; ON run BIOM/WBID identical to OFF).
Governors: droplet count / lifetime / per-cell carve cap (ledger-enforced, thrown
on violation). Sea clamp: below-sea cells read-only, land never carved below
sea+margin — rendered coastline provably fixed (asserted per generation). Crater
excluded at 1.2×R. Deterministic from resolvedSeed+9271 (PCG32). New EROS
blueprint section (writer/parser/harness/format doc). Supersedes the reverted D8
approach with the organic droplet model.
Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>
The task-10 draft's PASS B shipped and produced the canonical grid
artifact: thousands of straight, disconnected, pooling scratches. Per-
cell steepest descent on a regular grid can only route along its eight
neighbour headings, so at map scale the "channels" read as hatching,
not drainage. Reverted entirely rather than tuned -- no K, p or mask
setting fixes a directional basis. Rivers and erosion move to Phase C
as a hydraulic-erosion pass over FINAL terrain.
Removed: FlowAccumulation / IncisionWeight / EdgeBlend and the INC_*,
SEA_CLAMP, SHELF_INC_WEIGHT and CRATER_* constants; RunIncisionPass and
the pass-2b call; the six incision fields from TDTL (writer, parser,
harness). KEPT, untouched and developer-approved: pass A, the shelf
micro-relief skin, and its ShelfReliefAmp dial.
The crater carve folds back into the single pass-2 loop it came from,
carving two LOCALS written once each. That is what the code did before
the draft split it out, and it makes the aliased double-carve that the
split introduced (fix 1b98fb5) structurally impossible rather than
merely fixed -- there is no longer a read-modify-write to get wrong.
TDTL bodies are now versioned (BlueprintFormat.TDTL_VERSION = 2) and the
parser skips a body version it does not know instead of misreading the
longer v1 layout into plausible nonsense. The only v1 payloads that
exist are in the reverted batch's own tree.
Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
Two paired detail passes on the locked v5 skeleton, output-heights
only (classify path untouched):
PASS A — shelf micro-relief: +-ShelfReliefAmp (default 3 m) Simplex
skin (seed resolved+7409, ~40 undulations/island ~ 200 m features),
weighted by shelf-ness (full mid-shelf, feathered to zero 30% of a
band half-width into the risers) — both shelves get their rolling
texture back; risers and peaks untouched.
PASS B — drainage incision: D8 steepest-descent routing + height-
ordered flow accumulation over the curved+relieved land
(TerrainDetailPass — pure array machinery, named C++ candidate per
D-035); depth = K*accum^p*slope (K=0.78, p=0.45 concave, cap 30 m),
masked full on risers / 30% on shelves / zero on the toe, above the
plateau top, and within 1.2x CraterRadius (feathered to 1.4x); hard
clamp: carved height >= sea + 1 m. Ordering: curve -> relief ->
incision -> crater carve (the carve stays the final authority; carve
moved to its own pass 2c, bit-identical expression on both maps).
The pass prints its own MEASURED depth distribution.
Gate TerrainDetail "off"|"v1" (default v1; both passes one judged
unit; no-op without the curve) + ShelfReliefAmp dial. New TDTL section
(38 B: version + relief/incision params + seed offset) across
writer/parser/harness — blueprints stay self-describing.
Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>
0_height: hypsometric storm-ladder tint x Lambert NW hillshade over
the curved heights, captured after topography in both curve modes —
relief is finally visible. Renumbers nothing.
TCRV (50 B, emitted when the curve is on): curve version + input knots
+ output bands, so blueprints are self-describing about the map their
heights went through (H7 spirit). Parsed into
WorldBlueprint.TerrainCurve (null = raw legacy profile); server treats
it as metadata. Round-trip harness compares it when present.
Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>
Three new v2 tagged sections carrying the water-bodies stage output:
WBID (MapSize^2 u16 body ids; 0 none, 1 ocean, 2..N lakes), WBTB
(count-prefixed 20-byte records: id, type, provisional salinity,
transitional flat surface level, pixel count, centroid), WSRF
(MapSize^2 u16 quantized levels; 0 = no-water sentinel, 1 + L*32768
encoding, ~7.7 mm world resolution). Written only when the blueprint
carries water; absent on legacy re-encodes. Parser registers all
three (length + type checks) into new WorldBlueprint members —
consumed by nothing at runtime. Round-trip harness now compares the
water sections whenever the source carries them; v1-source baseline
stays green.
Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>
v2 tagged-section container (D-030): raw ISLA magic + u32 version gate,
[u32 tag][u64 length][payload] sections — params (resolved generation
inputs incl. impact centre), heights f32, biomes u8, towns with the
highway-node flag, four road tiers identified by tag not position.
- BlueprintFormat.cs: the single tag/constant registry.
- BlueprintWriter.WriteV2: blueprint-typed, callable outside a
generation run; generator and harness are both just callers.
- ExportMapData dual-writes: v2 under the primary seed name, legacy v1
beside it as _v1.dat (safety net; removal is a future task).
- MapDataParser: LoadMapDataFromPath entry point; v1 parse body
extracted intact as LoadV1 (v2 reader lands in the next commit).
- RoundTripHarness scene: load v1 -> write v2 -> load v2 -> semantic
equality, headless, seconds per cycle.
Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>
