The owner asked the question that unlocked this: "isn't the floor cut a modification
made to rooms afterward, instead of having them be naturally like so?"
Reading the code answered it, and the answer was that rooms and tunnels were built on
OPPOSITE principles:
room = SmoothMax(sphereSDF, floorHalfSpace), floor part of the SHAPE, evaluated
in one pass, with two octaves of Perlin relief already on the floor height
(FloorReliefStrength / RoomFloorCutMin=0.70, hash-rolled per room)
tunnel = a bare capsule with NO floor, then CaveTunnelFloorOp + support columns +
IsTunnelSupportFloorWorldPoint asserting a slab in afterwards
That is why tunnels read as "forced flat" and rooms never did, and why the previous
conditional-floor round could only find 1,539 skips in 1.5M tests: it was optimising
a correction instead of removing the need for one.
WHAT LANDED
Corridors now use a swept SmoothMax(capsule, floor): endpoint floor heights derived
from the rooms they join, deterministically interpolated along the control chain, the
existing two-octave relief reused (not reimplemented) and faded at mouths, and
TERRACES where a room-to-room transition is too steep -- risers capped at 1.71 voxels
(42.75 cm), with relief disabled on risers so the step bound holds.
player-fit cells 20,153 -> 20,835 (+682)
reachable cells 10,483 -> 10,901 (+418)
connectivity connected, both; mouth gap 0
vertices/tris 40,623/75,776 -> 40,429/75,416
dihedral p50/p90 2.5429/33.8499 -> 2.5529/33.7191 deg
Capability went UP, which is the point: the shape now provides what the correction
was faking, and it reaches places the slab did not.
RETIRED: the 1.5M-call natural-floor validator and its counters, plus the now-dead
CaveTunnelFloorOp / CaveTunnelAirOp implementations and profiler labels.
NOT retired: the finite support-column backstop. Removing it failed hard --
19,097 fit, 396 reachable, DISCONNECTED. It stays, and Codex was right not to force it.
⚠️ THE HONEST COST: 30% SLOWER
my own build, 3 runs: 1.509 / 1.542 / 1.543 s (was 1.118 / 1.131 / 1.197 s)
Well above the 17% noise floor. The relief evaluation is what costs.
⭐ And the fix is already identified: the relief is `FMath::PerlinNoise2D` -- a
function of (X,Y) ONLY -- yet it is evaluated per 3D sample. That is exactly the bug
pattern the support floor had, where making the decision per-column took it from
2.29 to 0.138 us/sample (16x). Caching relief per XY column should recover most or
all of the 30%. Next round.
Renders confirm the floors now undulate gently instead of presenting a flat plane;
the global relief metric is wall-dominated and inconclusive, and Codex correctly
declined to claim the visual complaint solved on that basis.
Determinism holds: both final runs hash 4520DC6F with canonical repeat equality.
Analytically the authored floor profile is bounded by tan(44 deg) including the
Perlin derivative and mouth envelope; the full post-modifier SDF still is not
provable, so the player-fit audit stays.
Build 0 errors. Nothing outside Plugins/VoxelForge; RealtimeMeshComponent untouched.
Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_012aheo2crrZmHuYtPpdY2Cb
Fr0zkaandClaude Opus 5
ff8bd7a8bc