The per-class breakdown refuted my own hypothesis on its first run. I predicted
"tunnels >> rooms, so it is capsule bounding spheres". Tunnels ARE wildly
over-counted (69.2 of 80.4 reach), but rooms hit all 40 tiles too, so fixing
tunnels alone would have moved the number by exactly zero. Fourth confident
chain this refactor that reversed on contact with a measurement.
The real finding is that the measurement was invalid. The sampler drew tile XY
from RandRange(-4,4)*8, i.e. +/-32 voxels, against RoomSpacing = 80 and a
guaranteed OriginRoomRadius = 20 room at (0,0) whose cull radius is 42, with the
(0,0) spine descending exactly there. All 40 tiles sat inside the origin room's
cull sphere, in the most cave-riddled spot in the world. "4.9 of 7.2 rooms
reach" was measuring the spine hub, not the world's cave density -- every
conclusion about whether deep rock is provable was answering another question.
Widened to +/-320 voxels (4x RoomSpacing). The report now prints its own
sampling extent and how many tiles landed clear of the spine, because a sampler
whose extent you cannot quote is one nobody is watching. This changes what the
measurement LOOKS AT, never what it demands: every verdict is still brute-forced
voxel by voxel, so a wider sampler that produced a false verdict still fails.
Also worked out, before writing any code, why rooms cannot be tightened and
tunnels can. SmoothMin's penalty is exactly zero once |A-B| >= K, so the running
minimum saturates at K below the true minimum and Sdf >= min_i(SDF_i) - K for
ANY number of primitives. With K=4, WormNetworkRange=24, mods gating at 3K=12,
the threshold T is 24. For rooms the cull rejects at Rmax+3K=57 while an
"Sdf >= T+K" test rejects only at Rmax+T+K=73 -- the cull is strictly better.
For tunnels the cull is a capsule BOUNDING SPHERE, radius up to ~107 for a
200-long tube of radius 7, while the real segment distance rejects at 35. An
order of magnitude, and sound because TaperedCapsule is a genuine distance
function (verified, not assumed).
That disjunction is NOT in this build on purpose: it changes what Identity means
here, from "Sdf stays FLT_MAX" to "Sdf >= T", which is only sound if every
consumer threshold is <= T. Three premises still need reading rather than
assuming -- VF_NearCaveSurface's constant, the Blend passed to FSdfConvertOp,
and whether any modifier re-probes the SDF outside the box before its gate.
Fix the measurement first; it costs nothing and it is wrong today.
Unbuilt.
Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
Fr0zka
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