Second defect from the full 28-op EffectOverBox audit. Three ops roll a radius
as Lerp(MinRadius, MaxRadius, hash01), which lands in [min(A,B), max(A,B)] --
Lerp does not require A <= B. Their EffectOverBox sweeps lattice cells padded by
the largest radius a cell could hold, so a pad below the true maximum means the
cells are never examined and the op reports Identity for a box its own Eval will
fill or carve: no geometry, no collision.
FGridColumnMod ~1086 Max(MaxRadius, 0) exposed
FShaftFieldSource ~1436 Max(ShaftMaxRadius, ConnectorRadius) exposed
FIslandBlobSource ~1803 Max(IslandMinRadius, IslandMaxRadius) already correct
The third one is the argument: the concern was met and guarded once in this same
file, and the other two shipped without it. Fixed with FMath::Max3, a spelling
already used here (~2481) and in VoxelCaveMorphology.cpp.
Shipped defaults are ordered correctly (2/5, 2/7, 5/11), so this is a NO-OP at
defaults -- that is its acceptance signal, and any moved number means the diff
did more than intended. It needs a mis-ordered asset value, which nothing
prevents: ClampMin is a per-property floor and UE cannot express "<= that other
property". ColumnMinRadius is also settable per-room via UVoxelTerrainOpDefinition.
Deliberately NOT fixed by normalising the params: swapping the Lerp endpoints
maps the same hash to a different radius, changing geometry and breaking the
eight equivalence tests. Only the bound becomes conservative; Eval is byte-
identical -- verified, no Eval/Roll/GetCells line in the diff.
Also audited and found sound (recorded so they are not re-chased): FPassageCarveOp
and the passage bounding sphere, FOriginSpineOp, FBoundarySealOp, FShaftLedgeMod,
FCaveArchMod, FDomeMod.
Not built -- Jahni builds.
Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
