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>
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>
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>
Q3: fable-idea F20 phases 1/2 and F18, REVIEW_FINDINGS perf pass 2 and batch 3,
and ARCHITECTURE's biome full-param redesign were all still carrying
"CODE-COMPLETE, PENDING BUILD" markers dated 07-04/-06/-08. Jahni confirmed on
2026-07-26 that everything is built and working (AUDIT-2026-07.md §0), so the
documents were misreporting project state. Ticked with the date they were
ticked, not just the date they were built.
Deliberately NOT ticked: ARCHITECTURE's F6 master material graph. Its C++ half
is built, but the material graph itself is editor-side work that is genuinely
still open, and ticking it would recreate the problem this queue item fixes.
CODEMAP discipline for this batch: new §3.2b (the VoxelDensityOp contract), new
§3.12 (Private/Tests), the EVoxelTileClass move into §3.2, and
FChunkBiomeCache::Invalidate under the biome types row.
Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
Fr0zka