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>
All 8 archetypes read line by line and broken into field source / combiners /
detail modifiers / structural post, with every FStrateGenerationParams field
traced to the op that will own it.
Three findings that change the sequencing:
- The op contract needs an SDF channel alongside density. Rooms, pits and
chimneys are SmoothMin'd in SDF space before a single carve, and three of the
four SDF archetypes add roughness to the SDF rather than to density. A
single-channel Eval can only overwrite, which is also why cross-source
SmoothUnion -- 'a maze inside a mountain that looks like it belongs' -- is not
expressible without it. Recommended before the Maze port; not applied, it is
Jahni's call.
- Worm tunnels are why TunnelNetwork can never skip a tile. A fielded 3D-noise
carve with no bounds forces CarveOnly everywhere, killing AllSolid for the
most-used archetype. But its amplitude is trivially bounded by WormStrength,
so a scalar cap recovers deep-rock skipping -- suggests one numeric bound
belongs in Phase 2, not Phase 3 as the plan has it.
- Disturbances already carry lattice bounds that ClassifyTile discards (it only
tests ChasmDensity > 0 strate-wide). Making them ops with real Identity tests
is a tile-skipping win for SurfaceWorld available independently of everything
else.
Q2 param audit: every field claimed except WaterLevelRelative, which is a
render/water property misfiled in the density struct and Lerp'd across strate
boundaries. Also flags three op names that mean different things in the cave and
surface structs and will collide the moment ops become assets.
Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
Fr0zka