Commit Graph

69 Commits

Author SHA1 Message Date
Fr0zka 8a303cc085 test(opstack B5): prove the bNearCaveSurface gate -- a voxel outside it is bit-identically untouched
STAGE B group 5 of 5, and the only one that adds no operator. Stage B is complete: 19 ops, all
twelve detail modifiers ported.

THE DECISION, restated where it is paid for
The gate is a repeated early-out inside each operator (VF_NearCaveSurface), not a scoping
container. Reasons live in the code at that function; the short form is that the stack is a flat
list ClassifyBox folds op by op, a container would have to re-implement VF_FoldOp and would hide
its children from the fold, and an op that only exists inside a container cannot become a Phase-3
asset. What that choice buys in composability it pays for in risk: TWELVE places to forget the
gate instead of one. Hence a check aimed at exactly that.

NEW CHECK 1d
Classify each sample by its final SDF (nothing downstream of the room source writes that channel),
then compare the full stack against one with the eleven controllable amplitudes zeroed:
  - outside the gate the two must be BIT-IDENTICAL -- asserted, and the leak count is printed;
  - inside the gate they must differ often -- printed, and ZERO is an error, because "nothing
    leaked" is worthless if the answer is "nothing happened anywhere". Same trap as a coverage
    guard that only fires at zero, one level up: a check can be vacuous as well as a counter.
  - the outside-gate sample count is printed and warns below 10%, since deep rock is the common
    case in production and a sample set that never leaves the cave does not exercise the gate.

WHAT THIS CHECK CANNOT COVER, stated in the output rather than left implicit: the column operator
(STEP 4d) has no amplitude to zero, so it cannot appear in the zeroed stack. Its gate rides on
check 1's bit-identity against the original instead. That is sound but invisible, which is why the
info line says so.

Also corrected in the test header: the modifier count is TWELVE, not the thirteen that had been
carried in the notes, and only ELEVEN of them read the per-room param copy -- surface roughness
(4b) sits before the shadow declaration and reads strate params. Both numbers matter for C1.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
2026-07-28 03:33:34 +02:00
Fr0zka b063d437c1 feat(opstack B4): port Columns (4d), Domes (4g), Pinch (4h), FloorBias + Column op in the test pool
STAGE B group 4 of 5 -- and with it, ALL TWELVE detail modifiers are ported. 19 ops:
  ConstantRock -> RoomGraph -> SdfCarve -> Roughness -> Terrace -> LayerLines -> Ribbing
  -> Overhang -> Cliff -> Scallop -> Arch -> RoomColumn -> Dome -> Pinch -> FloorBias
  -> Worms -> [structural x3]
Still NOT wired: UsesOperatorStackForChunk returns false for TunnelNetwork. What is missing is C1,
the per-room op override -- which adds NO operator, it changes what eleven of them READ.

TRANSCRIBED
- FRoomColumnMod (4d): walks SDFCache.Columns. Not FGridColumnMod -- that one rolls cylinders on a
  world grid for FlatPlain/CrystalChamber; this one iterates a per-room bake.
- FDomeMod (4g): upward half-ellipsoid, up to 2 per room, capped at 0.85 * room radius.
- FPinchMod (4h): perimeter-anchored ellipsoid with the SideFactor term that leaves the passage
  axis clear.
- FFloorBiasMod: quadratic fill below room centre, only in definite air. LAST in the chain and not
  interchangeable -- it exists to undo what roughness (4b) did to floors. That is why the operator
  order in BuildTunnelNetworkStack is the original's order line for line.

THE TRAP IN THIS GROUP, WHICH IS THE PIT LESSON A THIRD TIME
Columns have NO strate parameter. The per-voxel loop has no `if (ColumnDensity > 0)`, and the bake
reads OpParams (a FRESH struct with only the room's op applied), so FStrateGenerationParams::
ColumnDensity is read by nothing. Consequences, all three of which shaped this commit:
  1. The `ColumnDensity = 0` line in the old DisableStageBModifiers was inert. It was never what
     kept columns off; the absence of a Column op in the pool was.
  2. No FeatureProbes entry can cover columns -- there is no param to switch off. And a second
     stack built on a pool without the Column op would SHARE the thread_local SDF cache (the pool
     is not in its key) and return identical densities, i.e. it would lie. Exactly the trap that
     was documented for pits.
  3. So the stage-A guard that ERRORED on TotalColumns > 0 is inverted in this same commit: it now
     REQUIRES TotalColumns > 0. Asking the bake what it baked is the only sound check here.

DisableStageBModifiers is deleted rather than left empty: its emptiness is the measure of stage B
being complete, and an empty function still being called is how a step gets forgotten.

TEST (same commit): op count 15 -> 19; MakeShaftOpPool renamed MakeRoomOpPool and given a third
entry (Column, Probability 1.0 on all three so every room draws one of the three evenly); three
more param probes (dome/pinch/floor bias); the column guard inverted.

⚠️ THE POOL MUST STAY Pit/Chimney/Column UNTIL C1. Eleven of the twelve modifiers read the per-room
param copy in the original and the strate params here; those agree only while no room carries a
DETAIL-type op, and ApplyTo(Pit/Chimney/Column) writes only pit/chimney/column fields. A Terrace
entry would break the equivalence -- which is precisely the test C1 adds, and the only possible
proof that the override works.

IF THIS GROUP IS WRONG: dome/pinch/arch diffs land inside open cave near room centres and
perimeters; a column error shows up as a ring of diffs at fixed XY through the whole room height.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
2026-07-28 03:31:55 +02:00
Fr0zka 6ec60099d6 feat(opstack B3): port cave Overhang, Cliff, Scallop, Arch (STEP 4c)
STAGE B group 3 of 5. The stack is now 15 ops:
  ConstantRock -> RoomGraph -> SdfCarve -> Roughness -> Terrace -> LayerLines -> Ribbing
  -> Overhang -> Cliff -> Scallop -> Arch -> Worms -> [structural x3]
Still NOT wired: UsesOperatorStackForChunk returns false for TunnelNetwork.

TRANSCRIBED
- FCaveOverhangMod: fBM with Z frequency at 0.15x of XY, positive lobe only (rock extends INTO
  the cave, never away), quadratic fade. Note this is the THIRD unrelated thing called "overhang"
  in the plugin -- FOverhangShelfMod (SurfaceWorld) borrows the uphill terrain height and shares
  nothing with it but the name.
- FScallopMod: cellular noise, positive lobe carved out. Second consumer of VoxelNoise::Cellular3D,
  which is the second reason B1 shared that body instead of copying it.
- FCaveArchMod: the first ROOM-RELATIVE modifier -- it needs the room's hash, centre and radii, so
  it is what makes FRoomGraphSource::GetNearestRoomIdx() necessary. Its gate is NOT the shared one:
  CaveSDF < SDFBlendRadius (inside the cave), not < SDFBlendRadius*3.

PORTED AS-IS THOUGH THE ORIGINAL'S OWN COMMENT DISAGREES WITH ITS CODE
FCaveCliffMod's comment promises "sample density at Z+1 and Z-1, compute vertical gradient". The
code samples nothing: it draws a Perlin whose Z frequency is 3x its XY frequency and names the
result VertGrad. It is a gradient-shaped PROXY, decorrelated from the wall's actual slope; the
multiply by CaveSDF still gives it the right SIGN either side of the surface, which is why it
produces steeper faces at all. Fixing it would change the world, and saying nothing would leave it
to be "fixed" later by someone reading the comment instead of the code. Ported, documented in the
op, recorded in OPSTACK-PROGRESS.

ONE DELIBERATE ADDITION
FCaveArchMod bounds-checks NearestRoomIdx with IsValidIndex before indexing; the original tests
only >= 0. The index comes from EvaluateSDFCached so it is valid by construction, which is exactly
why this can never change output -- only prevent a crash if that invariant ever breaks. Same class
of decision as the params fingerprint in the cache key: err on cost, never on result.

Overhang is FillOnly, Scallop is CarveOnly, Arch is FillOnly; only Cliff needs Both. Four of the
eight modifiers ported so far keep a usable direction for the fold, which matters for the
DECOMPOSITION 0.2 work later.

TEST (same commit): op count 11 -> 15, four params groups move into EnableTunnelFeatures, four
more per-operator coverage probes. ArchDensity is set to 0.9 rather than its 0.1 default and the
reason is written down: at 0.1 a room draws ~0.3 arches and the probe would report zero with
nothing wrong. Test coverage settings are not production values.

IF THIS GROUP IS WRONG: diffs concentrate inside open cave (arch) or in a band |SDF| < range
(the other three), and the roughness/terrace probes stay green.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
2026-07-28 03:26:40 +02:00
Fr0zka ab1a996cc5 feat(opstack B2): port Terrace, LayerLines, Ribbing (STEP 4c) + hoist the room source's per-worker state
STAGE B group 2 of 5. The stack is now 11 ops:
  ConstantRock -> RoomGraph -> SdfCarve -> CaveRoughness -> Terrace -> LayerLines -> Ribbing
  -> Worms -> [structural x3]
Still NOT wired: UsesOperatorStackForChunk returns false for TunnelNetwork.

STRUCTURAL CHANGE THIS GROUP FORCED
FRoomGraphSource's thread_local SDF cache moved out of Eval into a `static FState& State()`
accessor, because terracing re-queries the cache at Z+-1 and (from B4 on) columns walk it and the
room-relative ops need NearestRoomIdx. Kept `static`, i.e. SHARED BETWEEN INSTANCES, on purpose:
that is what the original does, and the test's stale-cache check (check 3) rests on two stacks
sharing this cache while the params CRC in the key keeps them from serving each other's rooms.
Making it a member would have turned that check green for the wrong reason.
This is the established pattern in this file, not a new one: FOverhangShelfMod reads
FSurfaceColumnSource, FShaftLedgeMod reads FShaftFieldSource, both via a non-owning pointer
handed over at build time. Terrace now reads FRoomGraphSource the same way.

TRANSCRIBED
- FCaveTerraceMod: the Z-only SDF gradient orientation gate, the optional noise displacement of Z
  before the staircase, the Edge = lerp(0.45, 0.02, Hardness) stair profile, the quadratic fade.
- FLayerLineMod: sine along Z, half-wave rectified, CUBED, subtracted.
- FRibbingMod: same sine shifted by PI/2, rectified, SQUARED, added.

THINGS THAT LOOK WRONG AND WERE PORTED AS-IS
- Terrace's two gradient probes use UNWARPED X/Y and RAW Z, while the field they probe was
  evaluated at WARPED coords and effective Z, and they exclude pits/chimneys. So the probe does
  not sample exactly the field whose slope it measures. Real, in the original, load-bearing for
  the look; noted in OPSTACK-PROGRESS rather than fixed.
- Terrace/LayerLines/Ribbing use raw WorldZ while roughness uses EffectiveZ. Deliberate in the
  original (geology stays horizontal whatever the strate's vertical scale).
- `&& CaveSDF < FLT_MAX` is redundant under the bNearCaveSurface gate; kept.
- NearestRoom is now reset to -1 unconditionally, which the original does not do (its thread_local
  keeps the previous voxel's value when RoomDensity <= 0). Unobservable there because no consumer
  runs; here the consumers are separate objects, and a stale value crossing an operator boundary
  is not something you find later.

Ribbing and LayerLines are FillOnly / CarveOnly rather than Both -- two detail modifiers that keep
a usable direction for the fold, which is more than the roughness or the terrace can say.

TEST (same commit): op count 8 -> 11; the three params move from DisableStageBModifiers into
EnableTunnelFeatures with spacings deliberately small against the sample window; three MORE
coverage probes, one per operator rather than one per group -- a single "B2" probe would stay
green while two of the three were wrong.

IF THIS GROUP IS WRONG: diffs cluster where |SDF| < spacing*1.5 near horizontal surfaces
(terrace) or in thin Z bands (lines/ribs). If instead the whole equivalence collapses everywhere,
suspect the FState hoist, not the three new ops.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
2026-07-28 03:22:21 +02:00
Fr0zka 6e29cbfe4c feat(opstack B1): port TunnelNetwork surface roughness (STEP 4b) + share the cellular noise
STAGE B of TunnelNetwork, group 1 of 5. The stack is now
  ConstantRock -> RoomGraph -> SdfCarve -> CaveRoughness(4b) -> Worms -> [structural x3]
8 ops (was 7). Still NOT wired: UsesOperatorStackForChunk returns false for TunnelNetwork.

TRANSCRIBED
- FCaveRoughnessMod (VoxelDensityOpStack.cpp): STEP 4b literally -- two octave sets
  (main + fine x3 with the +2000/+2500/+3000 offsets), the optional domain warp, the four-way
  noise switch, the min(TotalRough, 0) anti-fill clamp inside definite air, and the quadratic
  fade by distance from surface. Reads EffectiveZ, not WorldZ.
- VoxelNoise::Cellular3D moved verbatim from VoxelGenerator.cpp's `static CellularNoise3D` into
  VoxelCaveMorphology.h; the generator keeps a one-line forwarder, exactly as FractalNoise3D and
  RidgedNoise3D already do since T2.a. It lands in the cave header rather than VoxelNoise.h
  because it needs VoxelHash, and VoxelNoise.h must not depend on the cave header. Forking a pure
  function is how AUDIT C1 happened.
- HRidged3D added next to HFractal3D (same FVector round-trip, deliberately).

TWO THINGS THAT LOOKED WRONG AND WERE PORTED AS-IS
- The domain warp computes ONE offset and adds it to BOTH noise positions, so the main and fine
  octave sets are warped identically. Two independent warps would be tidier and a different world.
- Roughness reads the STRATE params, NOT the per-room override. The original's
  `const FStrateGenerationParams& Params = LocalTerrainParams;` shadow is declared INSIDE the
  `if (bNearCaveSurface)` block that begins after step 4b. So eleven of the twelve detail
  modifiers read the room copy and this one does not -- flagged in the op so C1 does not
  "uniformise" it. (The handoff's "all 13 modifiers read the shadowed copy" is off on both counts:
  it is twelve modifiers, and one of them is outside the shadow.)

STAGE B5 DECIDED HERE, WITH REASONS (VF_NearCaveSurface)
The gate is a repeated early-out per op, NOT a scoping container: the stack is a flat list that
ClassifyBox folds op by op, a container would have to re-implement VF_FoldOp and would hide its
children from the fold, and an op that only exists inside a container is not a Phase-3 asset.
Cost stated rather than hidden: the original tests once and skips twelve, the stack tests twelve
times. Measured before optimised -- that is the C10 lesson.

TEST (same commit)
- Op count 7 -> 8.
- SurfaceRoughness/DomainWarp moved from DisableStageBModifiers into EnableTunnelFeatures.
- NEW check 1b, group coverage: rebuild the stack with the group OFF and count moved samples.
  Zero is an ERROR, not a warning -- a ported group that never executes is exactly how a bad
  transcription survives a whole green run (the PitDensity lesson). This diff-of-stacks is sound
  here although it lied for the op pool, because these are params and the params CRC IS in the
  SDF cache key.
- NEW check 1c: all 4 noise types x {warp off, warp on} compared to the original over 1500 points.
  The main equivalence only ever takes the FBM branch; three of four cases were untested.

IF THIS GROUP IS WRONG, what breaks first: the main equivalence reports diffs concentrated in
open cave and within |SDF| < SurfaceRoughness*2; if instead only check 1c fails, the fault is
inside one branch of the noise switch and nothing else is implicated.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
2026-07-28 03:18:21 +02:00
Fr0zka 7a87cdda14 docs: handoff — take the unattended queue all the way to 8 of 8
Jahni, twice and explicitly: he is fine with unverified work as long as it
is committed per group, and he wants the successor working toward full op
stack completeness. So the queue no longer stops at stage B.

Removed the hard stops on stage C and on flipping the ported list. Two facts
make that reasonable rather than reckless, and both are now written down:
committing per group IS the safety net (he reverts by sha), and reaching
8 of 8 does not change his world by itself — UsesOperatorStackForChunk still
returns false unless a strate has bUseOperatorStack ticked, so the flag flip
is inert until he ticks a box.

Queue is now B1-B5 (13 detail modifiers), C1 (per-room op override), C2
(Underwater, which §8 establishes has no density difference at all), C3
(both into the ported list = 8 of 8), then the §C2 audit question, the worm
amplitude cap, and making ClassifyTile consume ClassifyBox.

C1's design is settled here rather than left open, because an unattended run
should not be improvising architecture: take §2's option (a), and use the
mechanism this codebase already has three instances of — one op owns shared
state, others read it through a non-owning pointer (overhang <- column
source, ledge <- shaft source). FRoomGraphSource exposes LocalParamsAt();
detail ops read their fields from it. Same resolution as the pit/chimney
"fiddliest thing in the decomposition": the difficulty came from assuming
each op must own its params.

Still off limits: build, editor, push, ticking bUseOperatorStack on an
asset, and Phase 3.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
2026-07-28 03:05:33 +02:00
Fr0zka 473bccb43f docs: handoff — add an unattended-run work queue for stage B
Jahni may start a session and leave, then have it shut the PC down. The
successor still cannot build, so the section is about shaping ~680 lines of
mechanical transcription for ONE informative build afterwards rather than
pretending verification is available.

Work queue B1-B5 (roughness / terrace-layerlines-ribbing / overhang-cliff-
scallop-arch / columns-domes-pinch-floorbias / the bNearCaveSurface gate),
one commit per group with the group named in the subject line, since Jahni
reverts by group. Transcribe literally, note anything that looks wrong in
the log and port it as-is anyway — that is how C1 and the MinDivisor split
were both found without breaking anything.

Records the subtlety that lets B precede C: the 13 modifiers read a copy of
the params with the nearest room's op applied, so porting them against
strate-level params is equivalent only while the test's room pool stays
Pit/Chimney-only.

Hard stops: do not flip TunnelNetwork or Underwater on, do not start stage C
(design freedom without feedback), do not start the worm amplitude cap (it
changes the fold contract all 13 tests rest on), do not build or push.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
2026-07-28 03:02:43 +02:00
Fr0zka b888b86729 docs: stage A verified with real coverage; rewrite the handoff
The run that matters: bit-identical over 6000 samples with 23.9% of them in
open cave, and a bake carrying 49 rooms / 56 pits / 28 chimneys / 0 columns
— so the pit and chimney loops finally ran on real data, and 0 columns
confirms STEP 4d stayed dormant as stage A requires.

Same code and same colour as the previous green run, three different
strengths of evidence. That is the argument for printing coverage numbers
rather than pass/fail.

Handoff rewritten for a fresh context: the three-stage TunnelNetwork plan
and why stage A is verifiable while incomplete, the calls-not-transcribes
rule for BuildChunkCache, FRAME ops recorded as retired (0 of 3 candidates
needed one), the per-room override reclassified as load-bearing rather than
polish, and the method lessons regrouped around the three coverage traps.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
2026-07-28 02:58:33 +02:00
Fr0zka 68e43238bd test: pits and chimneys never ran — ask the bake, not the density
Check 3b earned its keep on its first run: 0 of 1500 points moved when
PitDensity was zeroed, because BuildChunkCache bakes pits inside
`if (!CR.RoomOp) continue;` and then reads a FRESH param struct with only
that room's terrain op applied. FStrateGenerationParams::PitDensity is
never read by the bake. Pits, chimneys and columns exist only through a
per-room UVoxelTerrainOpDefinition, and the fixture had none.

Not a product bug: those fields carry no UPROPERTY, so no editor surface
offers a setting that quietly does nothing. My reading was wrong.

Three attempts, and the second is the instructive one. Zeroing the params
tests fields nothing reads. Building a second stack with an empty op pool
would have LIED — the op pool is not in the SDF cache key (LayoutVersion
covers pool edits in production), so both stacks share the thread_local
cache and report "no contribution" for a third wrong reason. So: ask the
bake what it baked. Rooms > 0, pits > 0, chimneys > 0, columns == 0.

The test now attaches a real Pit/Chimney op pool. Safe at stage A because
ApplyTo(Pit) writes only pit fields, so none of the 13 unported detail
modifiers wake up — a Terrace op there would break it, which is exactly
what stage B adds.

Also reworded the green equivalence message, which claimed pits and
chimneys were exercised while zero existed. A success message that asserts
coverage instead of reporting it reads as evidence while measuring nothing.

Cave coverage 1.1% -> 21%, fingerprint 0.75% -> 95.8%.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
2026-07-27 19:22:07 +02:00
Fr0zka 5bf61c1815 test: stage A is bit-identical — strengthen the test its own counters indicted
The port is correct across 6000 samples. The only failure was arithmetic in
the assertion: 4 ops + 3 structural = 7, and I wrote 6.

But two numbers that PASSED are the real finding. 65 of 6000 samples landed
in open cave (1.1%), so the equivalence mostly compared solid rock to solid
rock — the carve, pits, chimneys and worm carve only run near the network.
And 3 of 400 probe points genuinely differed between the two param sets, so
the stale-cache check asked its question three times and said "fine" 397
times about points that could never have answered it.

Both counters were written to say exactly this, and did. Both guards only
fired at ZERO, so the run went green with the coverage of a much smaller
test. A coverage guard that only trips at zero does not measure coverage,
it notices absence. Both are now fraction thresholds that print a percent.

RoomSpacing 80 -> 42, RoomDensity 0.35 -> 0.85.

New check 3b: rebuild the stack with PitDensity = ChimneyDensity = 0 and
count the points that move. Enabling a feature in the params is not evidence
it fired — SDFCache.Pits can come back empty and the test stays green — and
these are the two loops DECOMPOSITION §2 calls the fiddliest in the plugin.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
2026-07-27 18:41:56 +02:00
Fr0zka ef5bda3d8a feat: TunnelNetwork stage A — the SDF spine, wrapping BuildChunkCache
The last archetype is ~1080 lines with 13 detail modifiers, a two-region
cache and a per-room op override. Porting it whole before anything can be
verified is ~600 unverified lines on top of ~200 — the pattern this
refactor has dodged six times. So: three stages.

Stage A = vertical scale, base rock, cave warp, room graph (+ pits and
chimneys), carve, worms, structural post. 6 ops. It is verifiable NOW
because every detail modifier is amplitude-gated and FStrateGenerationParams
already defaults them all to zero — zeroing SurfaceRoughness sends the
ORIGINAL down exactly the path stage A ported.

TunnelNetwork stays OFF in UsesOperatorStackForChunk until stage C.

The decision that matters: FRoomGraphSource CALLS BuildChunkCache and
EvaluateSDFCached rather than transcribing them. That is where §8.4's
two-region window-invariance discipline lives; a transcription would fork
it, and the fork would be "validated" by a test comparing it to the
original. Only the ~60 lines of glue are transcribed.

FRAME ops are retired. All three candidates are now ported and none needed
one: CaveWarp's scope is exactly one operator (pits/chimneys read unwarped
coords), VerticalScale is a one-line pure function, and the island warp was
already local. Not missing infrastructure — one idea seen three times from
a distance.

Also: check 3 was going to compare two interleaved param sets against the
original, which would have FAILED — the original's SDF cache key has no
params, so it serves B the rooms it built for A. Comparing there measures
its bug, not the port. Rewritten against each stack evaluated alone. The
same reasoning suggests a live production staleness across Gradient
transitions; filed in AUDIT §C2 as SUSPECTED with the check that would
confirm it, since it rests on a premise I have not verified.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
2026-07-27 18:28:06 +02:00
Fr0zka 96e75abe57 feat: port FloatingIslands — the stack that runs backwards
6 of 8 archetypes ported. This one starts from VOID and FILLS where the
other four start from ROCK and CARVE, which is what it was worth doing:
neither end of the pile needed a new operator, only the opposite sign.

  FConstantRockSource -> FConstantFieldSource(+/-Base)   AllSolid <-> AllAir
  FSdfCarveOp         -> FSdfConvertOp(Sign = +/-1)      carve    <-> fill
  FSdfRoughnessMod                                       4th archetype, unchanged

Only the island blob source is new. Multiplying by +/-1 is exact in
IEEE-754, so the three already-green ports are bit-for-bit untouched.

ClassifyBox can return AllAir for the first time in the plugin, and an
island strate is by construction mostly empty — the test counts AllSolid
and AllAir separately so an aggregate cannot hide whether that fired.

Two bounds that would have been holes if assumed rather than derived:
the island bound is one-sided (a hairline thread of matter hangs below
each island down its axis, so only the TOP may reject), and the domain
warp displaces X and Y independently, so the pad needs WarpAmp*sqrt(2).

Also: AUDIT C1 was NOT closed. The 2026-07-27 sweep matched `SeedF * K`
and this archetype's warp spells it `(float)S * K`, so one site survived
— at seed 2e9 the warp flattens and every island snaps back to a perfect
circle. Fixed in both paths in one pass so the equivalence test stays a
valid oracle. Expect island silhouettes to change at large seeds.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
2026-07-27 17:50:36 +02:00
Fr0zka f5d5a03ad1 docs: end-of-day handoff — 5 of 8 ported, 11 tests green
Rewrites OPSTACK-HANDOFF.md for a fresh context: the port table, what is left in
order, the two things Phase 2 invented that were not in the original design (height
space as a second operator family, and IVoxelBiomeField so ops depend on a capability
rather than the generator), and the method lessons that cost build cycles to learn.

Open items, none blocking: perf (parked by Jahni), C9's library half (no measured
risk), VerticalShafts' pessimistic box verdicts, and ClassifyTile still using
hand-written guards while ClassifyBox sits verified but unconsumed — which is where
the measured tile-skipping would actually become frames.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
2026-07-27 17:17:35 +02:00
Fr0zka d0a9ce3018 fix: the column key omitted the params — my perf fix broke the overhang
VerticalShaftEquivalence is bit-identical (966 samples inside a shaft), so operator
reuse across archetypes is measured now, not intended.

But SurfaceHeightEquivalence failed: 69/20000 overhang samples differ, 1 crossing the
isosurface. Cause is the ColumnKey from f3faa3b, which was
hash(StrateBottomWorldZ, LayoutVersion, Seed) and omitted the params. Two stacks of
the same strate with different overhang settings therefore shared a key, and the
second read the first's columns, computed with OverhangAmp = 0. The overhang silently
vanished wherever a column was already cached.

Not a test artifact: this is the weakness the codebase already documents for
GSurfColCache (extended AUDIT C2 note) — a live edit that changes params without
moving the strate leaves the key unchanged and serves stale columns. Production masks
it because RebuildStrates bumps LayoutVersion; my key inherited the hole.

Fixed by folding an FCrc::MemCrc32 fingerprint of the params, and of every per-biome
param set, into the key. FSurfaceGenerationParams is verified pure POD, so a memory
CRC cannot produce a false hit; padding can only cause a false miss, i.e. a recompute.

A perf optimisation introduced a correctness bug and the tests caught it the same
day. The failure was invisible to inspection and produced plausible terrain.

Known and not fixed: VerticalShafts proves 0 of 60 tiles because EffectOverBox
returns CarveOnly whenever any shaft sits within a Spacing*1.6 halo rather than
testing real connector capsules. Pessimistic, not wrong — lost CPU, never a hole.

UNVERIFIED: not compiled.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
2026-07-27 17:13:50 +02:00
Fr0zka 3acb3fbc6b feat: port VerticalShafts — three ops reused from Maze unchanged
The port that tests the thesis rather than the fidelity. Previous ports asked whether
the decomposition reproduces the original; this one asks whether operators actually
get reused across archetypes, which is section 2.5's claim and the only reason to do
this refactor instead of tidying the switch.

ConstantRock, SdfRoughness and SdfCarve are Maze's, reused without a line changed.
In the switch, GetMazeDensity and GetVerticalShaftDensity are two ~100-line functions
with nothing visibly in common; as operators they are the same three ops with a
different source and different tuning (freq 0.1 vs 0.12, window rough+4 vs R+rough+2).

New: FShaftFieldSource (infinite cylinders + hash-gated connectors into the SDF
channel) and FShaftLedgeMod (banded shelves on the +X/+Y half so the shaft stays
climbable).

Deviation from section 6, stated: it suggested splitting the source so the XY-pure
cylinder half could get an exact box verdict. Kept as one op because the connectors
derive from the same 3x3 roll and the ledge mod needs the shaft list anyway, so
splitting means rolling twice or sharing a cache between two ops. Forfeited: the exact
verdict on the cylinder half. Kept: a conservative EffectOverBox testing circles and
connector reach.

FShaftLedgeMod gates on the POST-roughness Sdf as the stack left it; re-deriving it
would use the pre-roughness value and shift every ledge. Reading the channel rather
than recomputing is what the two-channel sample is for.

Compile fix: FCells was declared below the functions returning it. Member bodies are
deferred, return types are not.

Ported: Maze, FlatPlain, CrystalChamber, SurfaceWorld (biomes included),
VerticalShafts — 5 of 8.

UNVERIFIED: not compiled past the FCells fix.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
2026-07-27 17:11:07 +02:00
Fr0zka f3faa3b5c2 perf: the column memo threw itself away every chunk
Jahni measured what I had only flagged: generation is slower on the op-stack path.
Two compounding causes.

The memo was keyed on InstanceId, which changes on every stack rebuild — every chunk.
GSurfColCache, the cache this path replaced, is keyed on (XY box, StrateKey, Seed,
LayoutVersion) with no ChunkZ, deliberately shared down the whole vertical strate
stack. So a 4-chunk strate recomputed every column four times, including the cliff's
four extra structural samples per column.

And the table held 256 entries where a chunk is CHUNK_SIZE^2 = 1024 columns, so it
thrashed against itself within a single tile before any cross-chunk question arose.

PrepareChunk now derives a shared ColumnKey from (StrateBottomWorldZ, LayoutVersion,
Seed) — the same identity GSurfColCache uses — and the table is 4096 entries
(~150 KB/worker, in line with GSurfColCache's 6 x 59 KB). The memo is thread_local so
it already survived rebuilds; only the key was discarding the contents.

Sharing across chunk Z is sound because heights are XY-pure by type and the biome
field is documented Z-independent — the same justification GSurfColCache rests on.

ColumnKey starts at InstanceId rather than 0: slots initialise to Key = 0, so a zero
key would falsely hit the pristine slot at (0,0). Without PrepareChunk you get
per-instance caching, which is less sharing but still correct.

This may not close the gap entirely and I am not claiming it does. Virtual dispatch
and the hashed lookup vs a direct-indexed box both remain; they are smaller than a 4x
column recompute, but "smaller" is a guess until measured.

UNVERIFIED: not compiled.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
2026-07-27 16:59:37 +02:00
Fr0zka c277931a08 feat: SurfaceWorld complete — biome blending wired, guard removed
The two biome checks added last commit printed nothing on success, so a passing run
was indistinguishable from a block that never executed — the exact flaw I flagged
twice this session and then wrote myself. Both now report their coverage.

Step 2c closes SurfaceWorld:

- FSurfaceColumnSource takes per-biome params and an OWNED IVoxelBiomeField. Empty
  params leaves the original path bit-for-bit unchanged.
- The field is owned by the stack rather than borrowed: the adapter points at
  GetDensityAt's thread_local biome context and cache, and the stack is itself
  thread_local rebuilt in the same refetch block, so all three live and die together.
  Structural ownership beats a convention the next reader has to infer.
- The overhang amp blends across biomes — Lerp(Amp(PD), Amp(PN), W) with slope and
  threshold from the dominant only, as ComputeSurfaceColumn does. Interpolating the
  slope would be meaningless; it measures the terrain rather than configuring it.
- FGeneratorBiomeField lives in VoxelGenerator.cpp, on the side that knows the
  generator. The op sees a capability, never an owner — which is what lets it become
  an asset in Phase 3.
- The no-biome guard is removed from UsesOperatorStackForChunk.

Also: the two constructors now delegate to one body with one id counter. The first
draft had two competing counters, one tagged with a high bit to avoid collision,
which is a smell rather than a design.

5 of 8 archetypes ported: Maze, FlatPlain, CrystalChamber, SurfaceWorld.

UNVERIFIED: not compiled.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
2026-07-27 16:51:18 +02:00
Fr0zka 1a3f6b6a72 fix: same stray-brace error as 7cd2bed — and label the boundary so it stops recurring
I anchored on the FACTORIES banner again, which sits after the anonymous namespace's
closing brace, so FBiomeBlendHeightSource landed at file scope and the `}` added with
it closed nothing. Identical to 7cd2bed, in the same file, for the identical reason.

Removed the early closer so the class keeps internal linkage with the other six.

The root cause is that the closing brace was unlabelled, so it reads as noise when
scanning for an insertion point. Both op files now mark it explicitly with what goes
above and what happens if you insert below. Cheap, and it turns a repeatable mistake
into a visible one.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
2026-07-27 16:46:18 +02:00
Fr0zka 6ad9f37a65 feat: the Mask combiner — biome blending in height space
Biome blending needs to ask which biome is at an XY, and the real answer is a warped
Voronoi with a per-chunk cache on UVoxelGenerator. The op must not hold a generator
pointer — Phase 3 wants ops to become assets, and one that owns a generator never
can. So it depends on IVoxelBiomeField, a two-line interface returning (dominant,
neighbour, weight), and the adapter that knows the generator stays on the generator's
side. Same move as cliff -> structural: depend on the capability, not the owner.

FBiomeBlendHeightSource holds one complete height stack per biome and lerps the
HEIGHTS in the border band. Each biome's stack computes its own relief and gates its
own terrace, exactly as the original makes two independent full calls and blends only
the outputs. Blending heights rather than params is what keeps borders continuous
across any param difference.

The ceiling SELECTS the dominant instead of blending, because that is what the
original does. Reproduced as-is rather than improved — a blended sky cap changes the
world's silhouette and a port is not where that gets decided.

Tested against a synthetic field rather than the real resolver: the resolver has its
own coverage, while a synthetic field sweeps the weight 0 -> 1 continuously, which is
where an inverted lerp hides. Five weights x 400 points, bit-exact against FMath::Lerp
of the two full stacks, plus a check that the ceiling still returns the dominant's at
weight 1.

UNVERIFIED: not compiled.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
2026-07-27 16:43:01 +02:00
Fr0zka 353c023dfd test: C9 is only half fixed — the libm half survives FPSemantics
All 9 tests green. LargeSeedSurvives proves C1 fixed by property rather than by
comparison: seed 2e9 (what FMath::Rand produces) now yields 400 distinct heights
over 400 samples where it previously gave a constant field. The three equivalence
tests stayed green through an 85-site rewrite.

The digest's NearIso warning fired at 2/115000 and its text blamed the /fp:fast vs
precise split, which is fixed. First instinct was "stale warning, soften it". Checked
instead, and the risk is real by a different mechanism:

sinf/cosf are not specified by IEEE-754. FPSemantics = Precise makes MSVC and Clang
agree on expression evaluation and says nothing about the math library; MSVC's CRT
and glibc's libm may differ by ~1 ULP. FMath::Sin/Cos are used throughout the density
path — layer lines, ribs, room placement, rotations. So C9's compiler half is closed
by construction and its library half is not, and no build flag can close it.

The measurement was also over-stating by ~100x: a single 1e-4 band is far too wide
for a libm-scale delta (~1e-6 absolute at densities of magnitude ~10). Replaced with
a three-band profile; only the tight band warns.

UNVERIFIED: the reworded test.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
2026-07-27 16:38:19 +02:00
Fr0zka cd4cf216f5 fix: AUDIT C1 — bounded, site-salted seed offsets across all 85 noise sites
The op stack had already inherited this three times and every remaining port would
copy it again, so fixing it now is cheaper than after.

The audit's documented fix was wrong: bounding SeedF while keeping the * 97.7f
multiplier still reaches 1.6e6, where the ULP is 0.19 — 9.5x the per-voxel step.
Less spectacular, still broken, ticket closed.

VoxelHash::SeedOffset(Seed, SiteKey) inverts the roles: the multiplier no longer
decorrelates by amplifying, it IDENTIFIES the site, and the hash decorrelates.
Output is in final units, bounded to [0, 16383], so the ULP is 10% of a voxel step.
Site-salted, so two seeds must collide at all ~50 sites rather than sharing one
global bucket.

Safe to apply without compiling because the transformation is a pure regex and the
literal stays visible at the call site, so each line remains eye-checkable against
the original. Applied to all three files in one pass so the archetype switch and the
ported ops changed identically — had they not, the three equivalence tests would say
so. 62 + 7 + 16 sites, none left, plus two bare `+ SeedF` worm sites by hand.

New test VoxelForge.Determinism.LargeSeedSurvives (seeds up to 2e9) because the
equivalence tests are structurally blind to this: they compare the stack against the
switch, both read the same faulty expression, so at a large seed both collapse
identically — bit-identical, green, and both flat. An oracle that shares the bug
cannot see it. This test asserts a property instead of a comparison.

EXPECT EVERY WORLD TO LOOK DIFFERENT: this re-rolls every noise offset in the plugin.
Intended, and covered by OPSTACK-PLAN 2.6.1.

UNVERIFIED: not compiled.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
2026-07-27 16:33:36 +02:00
Fr0zka f7ed9407bf feat: wire SurfaceWorld (biome-less) + fix a column-memo perf trap
All six checks green, 9399 samples inside the overhang window.

The single-entry column memo was correct only if the caller walks a Z column before
changing XY, which the mesher does not promise. Iterating X first within a Z slice
would miss on every voxel and re-run the whole height stack per voxel, cliff
resamples included — an order of magnitude on the plugin's most expensive archetype.

The tests could not have caught it: they sample random XY, where a one-entry memo
and a 256-entry one behave identically. Only reading the access pattern finds this.

Replaced with a direct-mapped 256-entry thread_local table hashed on the XY bit
patterns, full key compared on hit, so a collision costs a recompute and never
returns the wrong column.

Wiring: UsesOperatorStackForChunk returns true for SurfaceWorld only when the strate
has no biomes. The original blends heights toward the neighbouring biome across the
border band; the stack evaluates one param set, so a biome strate would get a hard
seam at every border rather than a subtle shift. The guard sits beside the archetype
list so "can this strate take the stack?" stays one question in one place, and
GetDensityAt keeps a defensive CP_BiomeCtx check that falls back if the two disagree.

UNVERIFIED: not compiled.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
2026-07-27 16:27:26 +02:00
Fr0zka 4dc55b1af3 feat: SurfaceWorld step 2b — the overhang shelf, the one op that is genuinely 3D
Step 2a green on all four counts, including FSurfaceColumnSource bit-identical to
GetSurfaceDensity over 20000 samples.

FOverhangShelfMod is the case that justifies where the two spaces were split: its
uphill reach grows with altitude (Frac = (Z - TerrainZ) / OverhangHeight), so it is
essentially Z-dependent and could not have lived in VoxelHeightOp.h. The boundary
falls where the code changes nature.

It needs TerrainZ plus a per-column gate (amp, uphill dir) the source computes.
Recomputing per voxel would pay the cliff's four resamples per lip voxel; adding a
third channel to FVoxelOpSample would put a COLUMN property in a per-voxel slot and
pollute a shared contract (section 11 has that open). Instead the source memoises
the column and the overhang reads it — the same shape as cliff -> structural.

The memo is keyed on (InstanceId, X, Y) with InstanceId from a monotonic atomic
counter, not on `this`: a freed stack and a newly allocated one can share an address,
a never-decreasing counter cannot collide. The stack evaluates every Z of a column at
one XY, so the hit rate is ~1 and this recovers per-column reuse without inventing a
second cross-chunk cache.

ComputeSurfaceColumn and SurfaceDensityFromColumn are now public: they are the only
oracle for the overhang, since GetSurfaceDensity passes OverhangAmp = 0. Private
declarations removed.

The test's third pass places half its samples inside the overhang window on purpose —
a uniform Z draw would almost never hit it and the test would pass having never run
the op, the same trap as WaterLevelRelative in the height pass. The in-window count is
reported and warns at zero.

Still missing before wiring: biome blending (the Mask combiner, section 5's Phase 3
prototype). Do not tick bUseOperatorStack on a SurfaceWorld strate with biomes yet.

UNVERIFIED: not compiled.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
2026-07-27 16:23:27 +02:00
Fr0zka 7cd2bed237 fix: stray brace — the sky cap class landed outside the anonymous namespace
My edit anchored on the FACTORIES banner, which sits AFTER the anonymous namespace's
closing brace. So FSkyCapHeightSource was inserted at file scope and the `}` I added
with it closed nothing — C2059 at the following `}`.

Removed the early closer instead of the late one, so the class keeps internal
linkage alongside the other five rather than leaking into the TU's global scope.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
2026-07-27 16:18:13 +02:00
Fr0zka 2b2afacd9e feat: SurfaceWorld step 2a — the bridge to density space; fix IsXYPure on the slab
Height stack is green: bit-identical to ComputeSurfaceTerrainZ on both passes,
including all four F20 terrain ops on. MaxDisplacement is loose (27% used) and left
that way — loose only costs CPU, tight-but-wrong is a hole.

FIX: FSlabVoidSource::IsXYPure() returned true and that was wrong. The contract is
"Eval does not depend on Z", and Eval computes min(Z - floor, ceil - Z). Section 3.1
made the SURFACES XY-pure; the density is a distance to them and never can be. I
conflated the two while writing the operator that quotes the warning against it.

Latent only because nothing reads the flag yet — and step 2b is where it would have
gone live, since a generic T1.a column cache keyed without ChunkZ would have shared
one density down the whole vertical chunk stack. AUDIT 6.3 says that corrupts every
chunk silently and ValidateDeterminism would not catch it.

That is also the clearest argument for the height-space split: what is XY-pure is
the HEIGHT, and in VoxelHeightOp.h it lives in a type with no Z to get wrong.

Step 2a:
- FSkyCapHeightSource: the ceiling is an altitude, so it belongs in height space
  rather than density space as section 5 had it — same category slip as the terrain
  ops. The subtraction happens later, in the combine.
- FSurfaceColumnSource: consumes both height stacks, IsXYPure false.
- BuildSurfaceStack: source + 3 structural, no per-column memo inside the op since
  T1.a already exists one level up and a second cache key is a second thing to get
  wrong.

NOT covered, and the test header now says so: the overhang (GetSurfaceDensity passes
OverhangAmp = 0, so only the cached path computes it) and biome blending. Both are
step 2b; do not wire SurfaceWorld into a biome or overhang world before then.

UNVERIFIED: not compiled.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
2026-07-27 16:14:39 +02:00
Fr0zka 921a9fb666 feat: height-space operator family — SurfaceWorld step 1, and C10 is solved
Maze and Slab now report BIT-IDENTICAL: FPSemantics = Precise, set for
cross-platform play, dissolved the ULP residue. Hypothesis 3 had the right
mechanism all along — under /fp:fast the compiler transforms by surrounding
context with no isolable axis, which is exactly why five one-variable experiments
all came back negative. Removing the permission removed the difference. Nobody
solved C10; C9 got fixed for an unrelated reason and C10 fell out of it.

SurfaceWorld step 1 forced an architectural decision. DECOMPOSITION section 5 notes
the height ops operate on Z values rather than density, then lists them as children
of FHeightfieldSource. Writing them made the consequence unavoidable: they do not
fit IVoxelDensityOp. No input Z (they produce one), XY-pure per column rather than
per voxel, and they write neither channel. Forcing them in would need a per-voxel
channel for a column property, or one opaque op — section 2.5's failure mode.

So height space gets its own contract: VoxelHeightOp.h (FVoxelHeightSample with
Height + Relief, IVoxelHeightOp, FVoxelHeightStack) and five ops. Relief is the
original's M — produced by the structural source, consumed by the terrace gate.
Section 0.1 found density needed a second channel; this found terrain needs a
second space.

The type system now forbids for free what AUDIT 6.3 warns about: a height stack
cannot hold Z-dependent data because there is no Z in the signature.

Deliberately staged — this touches nothing on the density path. If height space had
not decomposed cleanly, it shows up here for one test rather than after building the
adapter, the column cache integration and the dispatch on top.

The test runs twice; the second pass is load-bearing because the F20 terrain ops are
off by default, so a defaults-only run leaves all four modifiers untested. It also
brute-forces MaxDisplacement, since a false bound would later be a hole.

ComputeSurfaceTerrainZ moved private -> public for the test, same justification as
GetSlabDensity. Old declaration removed.

UNVERIFIED: not compiled.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
2026-07-27 16:06:50 +02:00
Fr0zka 25df4fceff build: complete the IWYU tail — APawn in VoxelWorld.cpp
VoxelWorld.cpp:526 dereferences the pawn, so APawn must be complete; Casts.h only
forward-declares it. Adds GameFramework/Pawn.h, and PlayerController.h which was
complete transitively only — the same fragility this change removes.

My earlier scan covered Public/ only. The shared PCH served .cpp files too, and
APawn was named in Build.cs's own error list. Everything else in the module
compiled, so this is the entire tail.

UNVERIFIED: not compiled.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
2026-07-27 15:56:06 +02:00
Fr0zka 6a60732c98 build: FPSemantics = Precise + clear the IWYU debt that blocked it
Jahni: cross-platform play (Linux and Windows, either side hosting) is a product
requirement, so fix C9 at the cause instead of measuring the symptom.

Verified in UE 5.7 source rather than assumed:
  VCToolChain.cs:1264    Default -> /fp:fast          Precise -> /fp:precise
  ClangToolChain.cs:712  Default -> -ffp-contract=off Precise -> -ffp-contract=off
Default really did mean opposite float models per platform; Precise collapses them
onto the same one, so a Windows host and a Linux client agree by construction.

Losing the shared PCH is what the IWYU debt hid behind. Every use turned out to be a
pointer, TWeakObjectPtr or TSubclassOf parameter, so forward declarations suffice;
only the templates and macros needed real includes. Seven headers fixed.

VoxelDensityVolume.h was the one worth catching: it tests ENABLE_DRAW_DEBUG in an
#if, and an undefined macro there is silently 0 — the debug block would have
vanished without a warning rather than failing the build. Include paths verified
against the engine tree, not guessed.

Expect a residual tail; the shared PCH hid these for years and only a build
enumerates them all. Build.cs now says so, and says the fix is to add the include
rather than revert FPSemantics.

Also adds VoxelForge.Determinism.CrossPlatformDigest: SHAPE digest (sign of density
= the world) and FIELD digest (bit-for-bit) over a fixed integer grid, plus NearIso
to bound how many samples could flip sign at all. Reports rather than asserts until
pinned. The cross-platform comparison itself is deferred per Jahni.

Expect a perf regression from losing reassociation and contraction on a noise-heavy
hot path — measure against ARCHITECTURE 8.10.

UNVERIFIED: not compiled.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
2026-07-27 15:53:23 +02:00
Fr0zka f1fd1e0b05 docs: new acceptance bar (peer agreement, not fidelity) — and C1's documented fix is wrong
Jahni: "I do not need your work to be identical or near identical to what I had
before, only having it 99.99% at worst reproducible if two people share the same
seed, since everyone rebuilds it on multiplayer."

Recorded as OPSTACK-PLAN 2.6.1, superseding 2.6's "recognisably the same place".
Consequences, each recorded where it will be found:

- C10 closed permanently rather than parked: it measures old-path vs new-path
  agreement and the two never coexist in a shipped world.
- The equivalence tests keep their value as PORT-CORRECTNESS checks, not fidelity
  checks. Isosurface hard-fail stays; ULP grading is diagnostic only.
- C9 promoted to top open risk. "Two people share a seed" is exactly what /fp:fast
  weakens across toolchains, and a Linux dedicated server against Windows clients
  compiles the density path under opposite float models. FPSemantics = Precise is
  the fix and the IWYU debt now blocks something that matters.
- C1 unblocked: it was deferred only because it re-rolls the world's noise.

Then, doing C1's arithmetic before applying its documented one-liner: THE FIX IS
WRONG. It bounds SeedF but keeps the * 97.7 multiplier, so the coordinate term
still reaches 1.6e6 where the ULP is 0.19 — 9.5x the ~0.02/voxel step. It would
have left the bug live for mid-range seeds while closing the ticket.

The real fix deletes the multipliers: they only decorrelate the ~40 noise sites,
which is a hashing job. VoxelHash::SeedOffset(Seed, Site) gives a site-salted,
bounded, final-units offset. Bounding SeedF alone would also funnel every seed
through 16384 offsets shared by all sites; per-site salting requires a collision at
all ~40 sites instead.

The op stack has already inherited the bug via FSlabVoidSource, so it must land in
both paths at once — and every further port copies it again.

Docs only; the C1 fix is not written.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
2026-07-27 15:43:23 +02:00
Fr0zka 51d8db842b test: fix the ULP yardstick — it measured output density, not where the error is born
The tuned pass warned: 121/20000 differ, 6 over the bound, worst 1.72e-05, still 0
isosurface crossings. The port is fine; the bound was wrong.

It was 16 * max(|Old|, 1) * FLT_EPSILON — ULPs on the OUTPUT density. But density is
min(Z - Floor, Ceil - Z), so near the isosurface the output tends to 0 while the
intermediates are in the hundreds. Rounding born at scale ~400 judged against a
yardstick of scale 1: 400x too tight, and tightest exactly where the test looks
hardest. Large amplitudes are what expose it, which is why the tuned pass earned
its place immediately.

Measured rather than assumed: amplitudes rose x2.25-3.33 and the deltas rose x4.5,
with the worst delta at 0.345 ULP of |Z| — sub-ULP at the scale it is born in. Error
proportional to amplitude is ordinary rounding. A wrong noise offset or a missing
abs() would move the surface by voxels, four orders of magnitude above this.

The bound now scales with max(|Old|, |Z|, strate Z bounds), and the warning prints
the discriminator instead of just the alarm: the density at the offending sample and
the delta in ULPs of the working scale. A few ULP at near-zero density is
cancellation; thousands is drift. That distinction is now readable rather than
re-derivable at a build apiece.

The box verdicts held under the worst case: 32/60 proved uniform, 0 unsound, under
tripled ceiling roughness and 3x the columns — exactly the case that stresses the
Max(CeilZ - noise, FloorSurface + 2) clamp.

Also recorded in DECOMPOSITION section 3: FlatPlain and CrystalChamber render
identical in the live world because nothing in the content distinguishes them. The
merge loses no distinction; it reveals there was none.

UNVERIFIED: the corrected bound.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
2026-07-27 15:39:03 +02:00
Fr0zka 85993199fb test: the slab test proved less than it claimed — add the pass that varies CeilingRoughness
SlabEquivalence came back green (FlatPlain 36/60 and CrystalChamber 40/60 tiles
proved uniform, vs zero for today's ClassifyTile; 52/20000 ULP-scale diffs, 0
isosurface crossings). But both archetypes reported the SAME 52 and the same worst
delta, which pointed at the fixture: FTestWorld::Build sets only GeneratorType, so
both slots carry DEFAULT slab params.

So the two passes were the same configuration at two depths. The test claimed to
demonstrate "one op, two archetypes" while never varying CeilingRoughness — the
only field that actually distinguishes CrystalChamber. The differing tile counts
come from the slots' Z ranges, not from the archetypes.

Third pass added: CrystalChamber(tuned), CeilingRoughness 6 -> 20, rougher floor,
3x the columns. It varies what matters and doubles as the worst case for the
ClassifyBox amplitude bounds — a large CeilingRoughness widens the ceiling band and
makes the FloorSurface + 2 clamp far more likely to bind, which is precisely where
a false verdict would be a hole. The default params were too gentle to stress it.

The ULP residue is left alone: deterministic, 0 isosurface crossings, and the same
shape C10 already cost six builds to prove not worth chasing.

UNVERIFIED: the third pass.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
2026-07-27 15:34:16 +02:00
Fr0zka 644339def5 feat: Phase 2 first port — FlatPlain + CrystalChamber collapse into one op
Jahni closed OPSTACK-DECOMPOSITION 3.1: the slab noise Z term was not
intentional character. Phase 1 also closed — the visual A/B on Maze passed.

Two changes, deliberately together, kept attributable by the test:

1. Design: GetSlabDensity's floor and ceiling noise lose their Z terms. A floor
   height no longer depends on the altitude you sample it from. The ceiling keeps
   its + 3000.0f, which is a decorrelation offset, not a Z term. The world
   re-tunes once — a different slice of the noise field, not a worse one.

2. Refactor: the now-XY-pure function ports to FSlabVoidSource + FGridColumnMod
   plus the three structural ops. BuildSlabStack has NO branch on archetype
   because GetSlabDensity never had one — CrystalChamber is FlatPlain with a
   bigger CeilingRoughness. 8 archetypes -> 7.

SlabEquivalence compares against the reference AS IT IS NOW and runs the whole
battery on both slots, so green means the port is a pure refactor and any visual
delta is attributable to the Z-term removal alone. The attribution comes from the
test, not from splitting it across two builds.

The payoff 3.1 was actually about: FSlabVoidSource::ClassifyBox is exact and needs
no sampling. FBM is contractually [-1,1], so both surfaces live in Z bands with
known bounds — a tile below the floor band is provably solid, a tile between the
bands provably air. ClassifyTile proves zero tiles for these archetypes today.
FGridColumnMod answers Identity when no column reaches the box, which is what lets
the source's AllAir verdict survive the fold.

UNVERIFIED: not compiled.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
2026-07-27 15:30:26 +02:00
Fr0zka 974e795b66 fix: call PrepareChunk and guard the degenerate strate on the wired path
Read the step-3 wiring against the equivalence test before spending a build.
The symbols all line up; the two PATHS did not.

- GetDensityAt never called FVoxelOpStack::PrepareChunk, though the test does.
  All seven concrete bodies are empty today so behaviour is unchanged — which is
  the reason to fix it now: the first op to hoist real per-chunk work would have
  been green in test and silently wrong in game. Builds an FVoxelOpContext in the
  same refetch block (chunk, seed, layout version, strate Z bounds). Step stays 1;
  GetDensityAt does not know the mesher's sampling step (T2.b).

- GetMazeDensity early-outs to air on a degenerate strate (height <= 0) and the
  stack has no such early-out by design. Unguarded that is air on one path and
  spine/seal-of-a-zero-height-band on the other, so the wired path now falls back
  to the switch there — the reference behaviour is the behaviour.

Docs: VoxelDensityOpStack.h's banner still claimed nothing here feeds the game,
and CODEMAP 3.2d repeated it. Both now state what is wired (GetDensityAt) and
what is not (ClassifyTile, hand-written guards, Phase 2), with C10's never-compare
rule at the point of use. CODEMAP gains UsesOperatorStackForChunk and
bUseOperatorStack rows, and BuildMazeStack's degenerate-strate precondition.

UNVERIFIED: not compiled.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
2026-07-27 15:15:59 +02:00
Fr0zka f7cccb044b docs: add OPSTACK-HANDOFF.md; install the 39 Unreal skills
Handoff: a pasteable resume prompt at the plugin root -- read order, exact state
(Phase 0.5 green, Phase 1 done and measured, step 3 written but not compiled),
the immediate next action, hard rules, open items, and the method lesson from
this session.

Skills: Jahni's UE library was at .claude/skills/core/<name>/SKILL.md, two levels
deep, where Claude Code discovers skills one level deep -- so none of the 39 were
loading. Flattened; 124 reference files intact, all frontmatter valid, folder
names already matched their name: field. core/category.md left as documentation.
Confirmed loading.

They are untracked and cannot be tracked without un-ignoring .claude/ itself
(git cannot re-include a file whose parent directory is excluded). Same shape as
AUDIT P1; flagged, not actioned.

Note for the next session: module-and-build-system documents PCHUsage, shared
PCHs and IWYU -- the exact mechanism that blocked C10's settling experiment. That
skill was in the repo, undiscovered, while it was worked out the slow way.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
2026-07-27 15:11:26 +02:00
Fr0zka 256a262140 feat: Phase 1 step 3 — wire the operator stack into GetDensityAt behind an opt-in
One branch on the density path, as OPSTACK-PLAN section 4 specified, and both
systems coexist.

- UVoxelStrateDefinition::bUseOperatorStack: the A/B switch section 2.6's
  acceptance bar needs. Flip it, regenerate, judge on a screenshot.
- UVoxelStrateManager::UsesOperatorStackForChunk(): the ported-archetype list,
  written down in exactly one place. An unported archetype ignores the flag and
  falls back to the switch, so ticking the box anywhere is harmless today and
  only Maze changes behaviour.
- GetDensityAt: CP_OpStack / CP_UseOpStack are resolved inside the SAME refetch
  block as the params, so the existing chunk + LayoutVersion key already covers
  them and there is no new invalidation logic to get wrong.

Hot-path cost is one bool test per voxel; the stack is built per chunk, the same
cadence as the param refetch. ApplyDisturbances and the diff layer stay outside
the stack and run once for both paths, so the tail of the pipeline is unchanged.

If UsesOperatorStackForChunk ever returns true for an archetype with no builder,
the code clears the flag and falls back to the switch rather than generating an
empty stack. An unported world is recoverable; a wrong one is not.

UNVERIFIED: not compiled. Likely spots: the `else switch` form, FVoxelOpStack as
a thread_local (move-only, reset by move-assigning a temporary), and the new
include.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
2026-07-27 15:03:00 +02:00
Fr0zka 34f06dfea7 docs: park the ULP residue as AUDIT C10; strip the diagnostic scaffolding
Jahni's call to pin it and move on, and the right one -- six builds spent and the
information stopped being worth the cost.

The final run closed it as far as it can be: SDFs identical everywhere (counted
unconditionally, 0 differ), yet two character-identical carve implementations in
the SAME translation unit fed a provably identical input differ by 1 ULP on
126/5000. That is only possible if they compile to different instruction
sequences, which /fp:fast permits based on surrounding context with no single
isolable axis. Hypothesis 3 was right about the mechanism and wrong about every
clean variable proposed for it, which is why four well-designed isolation tests
came back negative.

AUDIT C10 records the observation, what is proven (SDF bit-exact 126/126, zero
isosurface crossings), the five refuted hypotheses in a table so nobody repeats
them at a build each, why the settling experiment is blocked (shared-PCH / IWYU
debt), and the rule that actually matters: never run both density paths in one
world and never compare them for equality. That is NOT a client-desync risk --
within a binary the field is proven bit-pure and every peer runs the same path --
the cross-platform concern is C9, which stands on its own.

Corrected OPSTACK-PLAN 2.6 and C9: my earlier "/fp:fast across translation units"
explanation was measurably wrong and is removed rather than softened.

MazeEquivalence keeps the permanent value (equivalence with ULP grading,
window-invariance, box-verdict brute force) and drops the verbatim copy,
three-way, bisect, inlining and constness experiments.

Phase 1 closed: Maze decomposes into 7 ops, SDF bit-exact, 0 isosurface
crossings, window-invariant, and 23 of 60 tiles proved uniform where ClassifyTile
proves zero.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
2026-07-27 15:00:46 +02:00
Fr0zka b6ccb1c9f1 test: constness isn't it either — add the one unambiguous check, then stop chasing
CONST-Blend == runtime-Blend exactly (0 differ) and both miss the verbatim on the
same 126, so Blend's constness is not the variable. Five hypotheses, five dead.

Worse: one number I reasoned from was circular. "FORCENOINLINE == operator stack
: 5000/5000" cannot fail by construction -- it feeds S.Sdf to a carve and compares
against the density the stack computed from that same S.Sdf. It measures nothing,
and I read it as corroboration.

The two carve bodies are now dumped from the file and diffed: character-identical,
same translation unit. So one of expression / TU / input is not actually
identical, and the counters can't say which because the SDF comparison only ran
inside the mismatch branch.

Added: feed my carve the SDF the verbatim reports using and compare to the
verbatim's own output, plus count S.Sdf != VerbSdf directly with no enclosing
condition. That distinguishes "same function, same input, different output"
(measurement artefact) from "the SDFs were never equal outside the mismatch set"
(fault back in the lattice).

Proportion: this is the last build worth spending here. The port is already
verified where it matters -- SDF bit-exact 126/126, 0 isosurface crossings out of
20000, geometry identical, window-invariant, every box verdict brute-forced. The
open question is why the final rounding differs by 1-2 ULP, and no decision in
this project turns on it. If the check doesn't resolve it: accept, correct the
docs, strip the scaffolding, resume Phase 1 step 3.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
2026-07-27 14:57:21 +02:00
Fr0zka 7189d51b7b test: the variable is compile-time-constant vs runtime Blend — one line to confirm
The inlining experiment partitioned everything, just not along the axis it was
framed on:

  inlined != FORCENOINLINE  : 0          inlining is not the variable
  FORCENOINLINE == op stack : 5000/5000  test-TU carve == other-TU op, always
  inlined == verbatim       : 4874/5000  126 differ, in the SAME TU

The test-TU carve matches the operator stack across a TU boundary perfectly and
disagrees with the verbatim inside its own TU, so neither TU nor inlining is it.
Sorting the five implementations by the one remaining difference splits them
exactly: A (GetMazeDensity) and C (verbatim) hold Blend as a compile-time
constant; B (FSdfCarveOp, a member) and both parameter versions hold it as
runtime data. A == C, B == Inl == Noi, and the groups differ. Every observation
today fits that and nothing else does.

Mechanism: under /fp:fast, folding Blend * 2.0f to the literal 4.0f enables a
contraction in SmoothStep01's 3.0f - 2.0f*x -- one rounding instead of two --
that the runtime form cannot get.

This matters beyond the bug: an op's parameters are DATA by design, which is the
entire point of the refactor, so they can never be compile-time literals again.
The ULP difference is therefore inherent and permanent for every archetype port,
and no care in transcription will remove it. That is the real reason bit-identity
is unachievable here -- the earlier /fp:fast note named the right compiler flag
for the wrong reason.

CarveConstBlend added: identical to CarveInlined except Blend is a compile-time
constant. Predicted to match the verbatim 5000/5000 and differ from the runtime
form on exactly 126.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
2026-07-27 14:53:02 +02:00
Fr0zka 34f8ca7953 test: localised to FSdfCarveOp — now testing inlining context, the right variable
The SDF is bit-identical on 126 of 126 mismatches (0xBFE1C886 both sides), so the
lattice, hashes, edge set and VoxelSDF::Capsule are exactly right. The entire
difference is in FSdfCarveOp, whose expression is character-identical to the
original and whose inputs are bit-identical.

Identical inputs plus identical expression plus different output means the
arithmetic is being EVALUATED differently. SmoothStep01 is x*x*(3.0f - 2.0f*x),
and 3.0f - 2.0f*x is exactly the shape MSVC fuses into an FMA: one rounding
instead of two, ~1 ULP.

Why the three-way missed this, recorded because it is a reasoning error rather
than a coding one: A and C are both straight-line inlined code, while B goes
through a virtual IVoxelDensityOp call, so FSdfCarveOp::Eval is compiled
out-of-line and can get a different contraction decision. The three-way tested
whether the TRANSLATION UNIT boundary changes the result -- it does not -- but the
real variable is the OPTIMISATION CONTEXT. I built a clean experiment for the
wrong variable and then believed its answer. Hypothesis 3 was right about the
mechanism and wrong about the test.

The new experiment isolates exactly that: the same carve expression, same TU,
once FORCEINLINE and once FORCENOINLINE.

  differ    -> contraction confirmed, the port has NO bug, accept the ULP floor
  identical -> contraction is not it, and FSdfCarveOp has a real logic bug that
               has survived four readings

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
2026-07-27 14:48:56 +02:00
Fr0zka 210602586e test: three-way says the fault is mine — compare the SDF channels directly
A vs C = 0 differ. Identical source in two different translation units produces
identical results, so the compiler was never the cause and the operator stack
differs for a logic reason. That kills the /fp:fast story for the fourth time
running, and for the first time points at code I own.

Reading has failed three times: the ctor clamps, cell FloorToInt, NodeCenter,
EdgeOpen's hashes and salts, the {-1,0}^3 sweep and its add order, the capsule
fold, and the carve are all identical to the verbatim copy line by line. So stop
reading and measure one level deeper.

MazeCoreVerbatim now optionally returns its SDF and edge count, and the three-way
compares SDF channels directly instead of inferring from densities:

  SDF identical, density differs -> fault is in FSdfCarveOp
  SDF differs                    -> fault is in FLatticeCorridorSource

It reports the split across all 126 mismatches and dumps the first one in hex
with the verbatim edge count, so a differing edge SET (a cache-key bug) shows up
as a count mismatch rather than needing to be inferred.

Docs to walk back once the cause is known, listed in OPSTACK-PROGRESS so they are
corrected once with the right explanation: OPSTACK-PLAN 2.6's "bit-identity is
unachievable" note, AUDIT C9's first consequence, and this test's own INFO text.
C9's second half -- that UBT's FP default differs by toolchain and the MP model
assumes bit-reproducible terrain -- stands; it came from the engine source, not
from this test.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
2026-07-27 14:44:11 +02:00
Fr0zka d5c71d6b68 build: revert FPSemantics (drops the shared PCH); answer the FP question in the test instead
Setting FPSemantics on VoxelForge broke the build with ~30 "undefined type"
errors -- UMaterialInterface, USoundBase, TSubclassOf<AActor>, APawn,
ENABLE_DRAW_DEBUG -- none of them FP-related. UBT can only share a precompiled
header between modules whose compile environments match, so changing FPSemantics
cost the module the engine's shared PCH and with it ~30 includes the plugin has
always relied on getting for free.

That is a genuine latent IWYU debt in seven files, and worth fixing on its own
terms one day, but not inside an unrelated diagnostic. Reverted, with the reason
recorded in Build.cs so nobody retries it blind.

The question it was meant to settle is now answered without touching any build
setting: MazeEquivalence compiles a verbatim copy of the Maze core into the
TEST's translation unit and compares three implementations of identical source --
the generator's TU, the op stack's TU, and the test's own.

  A != C          -> same source, different TU, different result: the compiler.
                     Nothing to fix in the port.
  A == C, B != C  -> source is TU-stable, so the op stack differs for a LOGIC
                     reason, and it is in FLatticeCorridorSource or FSdfCarveOp.

Duplicating code is normally a fault. Here it is the only instrument that can
answer the question, because three careful readings all concluded "identical" and
the test keeps disagreeing. Marked diagnostic-only; it comes out once answered.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
2026-07-27 14:39:09 +02:00
Fr0zka a49d440bf6 build: put FPSemantics=Precise on the VoxelForge module — the experiment never ran
FPSemantics is a per-module ModuleRules property. It had been set on the VoxelM
GAME module, while every line of density code lives in VoxelForge, which kept
compiling /fp:fast. So the run that supposedly "reproduced the residue under
precise semantics" ran under fast semantics and proves nothing.

Retracting the previous commit's conclusion: /fp:fast is NOT eliminated as the
cause, and the notes claiming AUDIT C9 and OPSTACK-PLAN 2.6 are falsified are
withdrawn with it. Those documents were fine.

My error, and the third of its kind today: I reasoned a confident conclusion from
an unverified premise, one paragraph after writing that the lesson was to
instrument rather than assume. Checking took one grep and I only ran it after
Jahni suggested it.

The line is marked TEMPORARY with removal instructions and a guide to reading the
result. Combined with the WORST-POINT DUMP already committed, one build now
separates the two possibilities cleanly:
  454 -> 0   : FP model was the cause; keeping precise then needs a profile,
               because it costs the vectorisation T2.a's SIMD work was buying.
  454 -> 454 : real logic difference; read the dump.

Either way the line comes back out afterwards.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
2026-07-27 14:34:50 +02:00
Fr0zka cca9e83182 test: /fp:precise reproduced the residue byte for byte — instrument instead of guessing
An /fp:precise build returned the identical 454 samples, identical max delta,
identical coordinate. A different float model producing byte-identical output is
proof that rounding is not the cause, so the /fp:fast explanation is dead. That
is three failed hypotheses on one discrepancy (FVector round-trip, then "check
the roughness window", then /fp:fast), each reasoned from plausibility and each
costing a build.

So: stop reasoning, print. FVoxelOpStack::EvalSample exposes the full sample, and
MazeEquivalence now dumps the worst point in raw hex -- both densities, the
stack's internal SDF, and the carve factor reconstructed from each side. The
recovered carve localises it: identical carve + differing density means the fault
is after the conversion; differing carve means it is in the SDF (lattice edges or
VoxelSDF::Capsule) or in SmoothStep01.

Note for whoever reads the docs next: AUDIT C9 and OPSTACK-PLAN 2.6 currently
assert the /fp:fast story as the explanation for THIS residue. That specific
claim is falsified and needs walking back once the dump identifies the real
cause. C9's other half -- that UBT's FP default differs by toolchain and the MP
model assumes bit-reproducible terrain -- stands independently; it was read out
of VCToolChain.cs and ClangToolChain.cs, not inferred from this test.

Phase 1 step 3 (wiring the stack into GetDensityAt) is paused until this is
understood. Small unexplained numeric differences do not get smaller when you
build on top of them.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
2026-07-27 14:32:22 +02:00
Fr0zka 0379d59c1c docs: AUDIT C9 — the FP default differs BY TOOLCHAIN, not just "fast is allowed to drift"
Jahni asked the right question: does the same seed produce identical results
across OS builds today? Checking the other toolchain made the answer sharper and
worse than what C9 originally said.

ClangToolChain.cs (Linux, Mac, Windows-with-Clang):

    case FPSemanticsMode.Default: // Default to precise FP semantics.
    case FPSemanticsMode.Precise: Arguments.Add("-ffp-contract=off");

and VCToolChain forces Precise when Windows uses Clang. So the same
FPSemanticsMode.Default resolves to OPPOSITE float models per toolchain, and
Windows/MSVC is the only imprecise configuration in the engine's defaults. Two
builds of identical source are not merely permitted to diverge -- they are
compiled under different rules.

Also added, so the entry does not over-fear itself:
- Calibration: 0 of 20000 samples crossed the isosurface under a 1-ULP
  perturbation, so divergence means occasional single-voxel surface differences,
  not different terrain. The case that bites is topological (a cave pinch-point
  connecting on one build and not the other), which is rare and unreproducible --
  the expensive kind.
- Precise everywhere still would not guarantee cross-platform bit-identity:
  FMath::Sin/Cos route to platform libm, which is not bit-standardised. It closes
  the large gap, not every gap.
- The knob would ALIGN Windows with every other platform rather than being a
  one-sided cost -- but still must not be turned speculatively.
- The claim is inferred, not measured. The cheap decisive test is one Windows
  build with FPSemantics = Precise: if MazeEquivalence's 454-sample residue
  vanishes, the FP model is confirmed as the sole cause.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
2026-07-27 14:19:42 +02:00
Fr0zka af5f2103b3 test: the Maze residue is /fp:fast, not port drift — encode the real bar
The bisect settled it. The difference survives every stage removal down to
"corridors + carve ONLY", which is character-for-character transcribed code, so
it is not in anything the decomposition added.

Cause, read out of the engine rather than assumed (VCToolChain.cs):

    case FPSemanticsMode.Default: // Default is imprecise FP semantics.
    case FPSemanticsMode.Imprecise: Arguments.Add("/fp:fast"); break;

with UBT's own doc: "the compiler is allowed to transform math expressions in
ways that might result in differently rounded results". Identical source in two
translation units may reassociate differently, worth ~1 ULP. It shows up on
exactly the ~2% of samples inside the SDF blend shell, where Blend - Sdf
catastrophically cancels; outside it Carve is exactly 0 or 1 and both agree.

So MazeEquivalence now grades what it can actually assert:
  - hard fail  : any isosurface crossing (geometry moves)
  - info       : differences at ULP scale (the unavoidable floor)
  - warn       : anything larger, which IS port drift, and runs the bisect
A test that warns on every port would get ignored by the port that matters.

Recorded in OPSTACK-PLAN 2.6, and as AUDIT C9 for the part that outlives this
refactor: ARCHITECTURE 9.1's "every peer regenerates identically" holds only
between bit-identical binaries under /fp:fast. Fine for one build on one
platform; a real desync source for a Linux server plus Windows clients both
regenerating authoritative geometry. The FPSemantics::Precise knob exists but
must not be turned speculatively -- it blocks the vectorisation T2.a was chasing,
on the hot loop, for an unmeasured cost.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
2026-07-27 14:15:43 +02:00
Fr0zka 23605d5350 test: bisect the residual Maze difference instead of guessing at it again
All six tests are green as of the 12:02 run, so Phase 0.5's gate is met.

MazeEquivalence still reports 454 differing samples, the same max delta, at the
same coordinate as before -- byte for byte the previous result. So the FVector
float->double->float hypothesis from the last commit is dead: that detour is a
no-op, exactly as /fp:precise says it should be. It stays (harmless, and it
documents the original's shape) but it explains nothing.

Rather than propose a third guess, MazeEquivalence now bisects: it re-runs the
comparison with roughness, then seal, then spine, then passages disabled ON BOTH
SIDES, and reports which stage's removal makes it bit-exact. One run answers what
two hypotheses failed to.

Standing hypothesis for the bisect to confirm or kill: compiler float
contraction across translation units under /fp:fast, worth ~1 ULP. It fits the
~2% hit rate -- only voxels inside the narrow SDF blend shell have an unsaturated
carve factor; everywhere else Carve is exactly 0 or exactly 1 and both paths
agree bit for bit. If confirmed, bit-identity is not achievable in principle for
these ports and the bar for every later archetype is "zero isosurface
crossings", which is what OPSTACK-PLAN 2.6 asked for anyway.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
2026-07-27 14:07:14 +02:00
Fr0zka 826a8c99dc fix: first-green-build follow-ups (diff-layer assertion + Maze float rounding)
The build passed and six tests ran; five green. Details in OPSTACK-PROGRESS.md.

1. DiffLayerContention's failure was the test, not the plugin.
   GetTotalModificationCount() sums STORED ENTRIES, not operations -- a stroke is
   filed under every chunk its AABB overlaps, so 400 radius-6 spheres straddling
   chunk corners store 3200 entries. The assertion now compares the stored count
   against the chunk fan-out ApplyModification itself returned, which also checks
   that the re-mesh list handed to the caller describes what was actually written.
   Everything the test exists for had already passed: 7 readers, 28.7M read
   rounds against 760 writes and 6 Clear()s, no crash, monotonic version.

2. MazeEquivalence: 454/20000 samples differed by at most 1.907e-06 -- exactly
   one ULP at magnitude 16 -- with ZERO crossing the isosurface, i.e. not one
   triangle would move. Leading hypothesis: the original routes noise coords
   through an FVector (double in UE5) and back to float, rounding twice, while
   the op passed floats straight through; under /fp:fast those round differently.
   The op now reproduces the detour on purpose, with a comment against
   "simplifying" it. Unverified -- it predicts 0 differences next run. If drift
   remains, next candidate is FMA contraction across translation units.

Also recorded, because it is the perf half of the whole refactor: the Maze op
stack proved 23 of 60 tiles uniform. ClassifyTile proves ZERO for any cave
archetype today.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
2026-07-27 02:40:51 +02:00
Fr0zka 62e3d5a933 fix(build): FVoxelOpStack is move-only, so it must not be a dllexported class
MSVC C2280 on TArray<TUniquePtr<IVoxelDensityOp>>'s copy path. Putting
VOXELFORGE_API on the class forces the compiler to instantiate every implicit
member, including copy-assignment -- which cannot exist for a move-only element
type. The export moves to AppendStructuralPost, the only out-of-line method.

Also declares the move-only-ness explicitly rather than leaving it implied. That
is the right semantics independently of the compiler: a stack uniquely OWNS its
operators, and copying one would mean cloning polymorphic ops, which is
meaningless here.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
2026-07-27 02:36:08 +02:00
Fr0zka 8a33bcb42a docs: CODEMAP rows + progress entry for the Phase 1 Maze port
CODEMAP gains 3.2c (VoxelDensityPrimitives), 3.2d (the operator stack and its
factories), FVoxelOpSample under 3.2b, and the two new tests under 3.12.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
2026-07-27 02:33:00 +02:00
Fr0zka 4c53d3bbed feat: Phase 1 — Maze ported to the operator stack, OFF the hot path
Maze decomposes into seven ops with no contortion:

  ConstantRockSource -> LatticeCorridorSource -> SdfRoughnessMod -> SdfCarve
  -> OriginSpine -> BoundarySeal -> PassageCarve

That is the answer to Phase 1's actual question (OPSTACK-PLAN section 4's
stop-trigger: "does the source/modifier split fall out naturally?"). It does.
Three of those ops are already shared: ConstantRockSource is the first line of
TunnelNetwork, Maze AND VerticalShafts; SdfCarve is the same six lines in all
three; the structural post is identical across all six density functions.

GetDensityAt and ClassifyTile are NOT touched. The archetype switch is still the
only path feeding the game, so nothing in a running world can change. The port
is validated instead by VoxelForge.OpStack.MazeEquivalence, which compares the
stack against GetMazeDensity over 20k points, re-checks purity across worker
threads, and brute-forces every box verdict the stack emits.

Two contract decisions, delegated and taken:

1. Eval is now two-channel (FVoxelOpSample { Density, Sdf }). Maze forces it:
   its roughness perturbs the SDF, not the density, and on density the same
   noise scales with the local gradient and is a visibly different effect. It is
   also what lets two different sources SmoothMin together later, which is the
   difference between a composed idea belonging somewhere and being punched into
   it.

2. The stack's density channel is INTERNAL convention (positive = solid),
   negated once by the caller. This REVERSES what the header said yesterday.
   Every archetype body is already written that way, so each port becomes a
   literal transcription instead of a sign-flip of every line -- on the plugin's
   documented #1 source of confusion. The SDF channel keeps standard SDF
   convention, so min() means opposite things on the two channels; the header
   says so loudly.

Also extracts spine/seal/passage from VoxelGenerator.cpp into
Public/VoxelDensityPrimitives.h so the generator and the ops share ONE copy of
three world invariants. Forwarders keep the local names, so not one of the ~20
call sites changes; bodies are byte-identical.

One thing found while writing the seal's ClassifyBox and NOT silently fixed: at
the inner edge of a seal band, 1 - Dist/Thickness can round to exactly 0.0f, so
SealFactor*BaseDensity is 0, internal density lands on 0, and the mesher counts
that as AIR. Claiming AllSolid there would be a hole. The new op keeps a 1-voxel
safety margin before it forces. Today's ClassifyTile has no such margin -- the
window is hairline and needs the archetype to produce air at exactly that z, but
it is real. Reported rather than patched, since Phase 1 does not touch that path.

UNVERIFIED: not compiled.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
2026-07-27 02:32:09 +02:00