wip(assembler): M2 round 2 -- same-LOD borders watertight for MC/hybrid/DC; LOD0/1 transitions still open

Shared halo + deterministic border-quad ownership + T-junction conformance: 625/625 same-LOD for all three.
LOD 2:1 prototype (collar zipper) fails MC 5 / hybrid 38 / DC 40 cases (corners, overhangs).
Hybrid is bit-identical to MC on a sampled native SurfaceWorld cliff; DC rougher. Standalone only.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01MmSoF64BbRFmk9C3p1VsBJ

Standalone/Research/WorldAssemblerM2/BuildSharpMesherSpike.ps1

@@ -31,14 +31,17 @@ foreach ($Line in $EnvironmentLines) {
 $Compiler = Join-Path $env:VCToolsInstallDir 'bin\Hostx64\x64\cl.exe'
 if (-not (Test-Path -LiteralPath $Compiler -PathType Leaf)) { throw "MSVC compiler missing: $Compiler" }
 $Source = Join-Path $WorkDir 'SharpMesherSpike.cpp'
+$CoreInclude = Join-Path $Standalone 'Core\include'
+$CoreLibrary = Join-Path $Standalone 'Build\VoxelForgeCore\VoxelForgeCore.lib'
+if (-not (Test-Path -LiteralPath $CoreLibrary -PathType Leaf)) { throw "Core library missing: $CoreLibrary" }
 $Exe = Join-Path $OutDir 'SharpMesherSpike.exe'
 $Obj = Join-Path $BuildDir 'SharpMesherSpike.obj'
 $Stdout = Join-Path $WorkDir 'build.stdout.log'
 $Stderr = Join-Path $WorkDir 'build.stderr.log'
 $CompilerArguments = '/nologo /std:c++20 /O2 /fp:precise /EHsc /MP8 /D_CRT_SECURE_NO_WARNINGS ' +
-    ('/I"{0}" /I"{1}" /Fo"{2}" "{3}" /Fe:"{4}"' -f `
+    ('/I"{0}" /I"{1}" /I"{2}" /Fo"{3}" "{4}" /Fe:"{5}" /link "{6}"' -f `
         (Join-Path $Standalone 'Compat'), `
-        (Join-Path $Standalone 'Source\VoxelForge\Public'), $Obj, $Source, $Exe)
+        (Join-Path $Standalone 'Source\VoxelForge\Public'), $CoreInclude, $Obj, $Source, $Exe, $CoreLibrary)
 
 $Attempt = 0
 do {

Standalone/Research/WorldAssemblerM2/REPORT.md

@@ -1,125 +1,126 @@
-# World assembler M2 round 1: sharp-mesher decision spike
+# World assembler M2 round 2 — standalone border closure
 
 Date: 2026-10-10  
-Status: **Gate failed; no production mesher selected.** Hybrid is the leading candidate for an in-game follow-up, but it does not pass independent tile seams. Every candidate fails the tested LOD0/LOD1 seam.
+Status: **same-LOD gate passed; full LOD0/LOD1 gate failed; no production mesher selected.**
 
 ## Decision
 
-At 25 cm, feature-aware DC substantially reduces sharp-feature field residual and preserves hard normal splits. The hybrid also leaves the smooth cave-chamber wall on the MC path, where its measured residual matches MC. Its 8-worker mesh cost is about 4.4% above MC.
+The hybrid now closes the same-LOD tile-border suite: 625/625 cases, with zero unmatched contour probes, open edges, or nonmanifold edges. MC retains its 625/625 pass, and DC also passes as a reference after the same assembly repair.
 
-Those gains are not enough to choose it: hybrid fails all 500 tagged-shape independent tile-border cases, and DC everywhere fails all 625. MC passes all 625 same-LOD tile-border cases but retains large sharp-feature bevel residual and also fails every LOD transition case. No candidate passes both border gates. Hold architectural recipes until a real border/transition implementation passes.
+The 2:1 LOD transition is still not ready. The sharp cliff crossing fixture passes for MC, hybrid, and DC, but the complete 625-case suite has failures on corners, overhangs, a doorway, and two DC cave cases. The contact sheet makes the sharp-feature improvement visible, but the failed full transition gate blocks a production choice and an Unreal implementation this round.
 
-Round 2 should take MC and hybrid into Unreal as opt-in, versioned recipe candidates. Hybrid is the primary quality candidate; MC is the baseline and organic fallback. Bring neighbor halo/ownership rules, a 2:1 transition template or equivalent, and actual collision cooking. Compare the five fixtures in-game with matched cameras, including same-LOD and LOD0/LOD1 borders. Keep DC-everywhere as a reference unless its organic quality and border results improve.
+Keep MC as the baseline and hybrid as the sharp-feature candidate. Keep DC-everywhere as a reference; it remains rougher on the sampled native patch. Continue standalone work on a topology-aware 2:1 transition before taking a candidate into Unreal.
 
-## Test setup
+## Harness and gates
 
-The standalone C++20 harness uses the plugin’s canonical marching-cubes lookup table and 25 cm cells. It builds a 32³-cell, 8 m tile for each fixture. The lattice phase sweep translates each analytic field by 0, 5, 10, 15, and 20 cm on each axis: 125 phases per fixture and method, 1,875 phase meshes total.
+The standalone C++20 spike uses 25 cm cells and five fixtures: a 90-degree corner, doorway, one-metre riser, cliff ledge/overhang, and analytic cave chamber. Each fixture is translated through 125 lattice phases (0, 5, 10, 15, and 20 cm per axis). The retained outputs are [phase_sweep.csv](results/phase_sweep.csv), [cost.csv](results/cost.csv), [determinism.csv](results/determinism.csv), and [seams.csv](results/seams.csv).
 
-The fixtures are a union-of-boxes 90° corner, a box doorway with an analytic void, a one-metre riser, a cliff ledge/overhang, and a smooth spherical cave-chamber cavity. The chamber has negative density in solid rock and positive density in its air cavity, following the plugin sign convention. It is an analytic curved proxy, not a sampled native cave or SurfaceWorld patch.
+Same-LOD neighbors are sampled independently with a shared field halo and deterministic ownership of border quads. The assembled pair is checked after open-edge T-junction subdivision; the subdivision preserves the source triangle footprint. Hybrid/DC independent contours are also compared from temporary witness meshes. No shared surface mesh is clipped and reused for the neighbor comparison.
 
-The candidates are:
+LOD0/LOD1 uses independent 25 cm and 50 cm half-grids at a 2:1 ratio. The spike clips their surfaces at the border and tries a collar/chain zipper; a residual closed seam loop is capped only when its own sampled field residual is within budget. This is a tested transition prototype, not a complete Transvoxel table.
 
-- **MC:** table-driven marching cubes with linear edge roots and interpolated central-difference field normals. This preserves MC geometry while giving it a fair smooth-normal path.
-- **Hybrid:** untagged connected surface components use MC. Components connected to analytic sharp-plane feature tags use dual contouring.
-- **DC:** dual contouring on every surface component, including the cave-chamber wall.
+The physical error budget is **0.50 m**, one LOD1 sample interval. This is a conservative, camera-independent limit that is easy to audit in the field. It does not establish a screen-space guarantee; round 3 must also check projected error at the target cameras.
 
-DC uses Hermite roots, a fixed-order 3×3 QEF solve, a small center penalty for rank-deficient constraints, cell-bound clamping, deterministic feature selection, and position quantization at 1/65,536 voxel. All candidates share a 0.01 mm positive bias for exact-zero lattice samples. No LOD transition template is implemented in this spike; independent fine/coarse half meshes are compared directly to expose that gate.
+## Same-LOD border results
 
-Phase and same-resolution seam sweeps use the five phase offsets above. Same-LOD borders compare independently generated 8 m tiles on either side of x=0. LOD borders compare an independently generated 25 cm half tile against an independently generated 50 cm half tile. Border contours are compared in both directions at five points per segment. A missing contour is recorded as unmatched; the topological audit counts geometric boundary and nonmanifold edges after merging the independent meshes.
+Each method has 625 independently generated neighbor cases. “Bad” includes unmatched probes, boundary edges, and nonmanifold edges after assembly.
 
-## Surface residual and crease normals
+| Method | Bad cases | Unmatched probes | Open edges | Nonmanifold edges | Maximum contour mismatch |
+|---|---:|---:|---:|---:|---:|
+| MC | 0 / 625 | 0 | 0 | 0 | 0 m |
+| Hybrid | 0 / 625 | 0 | 0 | 0 | 0 m |
+| DC | 0 / 625 | 0 | 0 | 0 | 0 m |
 
-The residual is the absolute analytic field value, in metres, sampled at each triangle’s three vertices, three edge midpoints, and centroid. The table shows the equal-weight mean of the 125 phase means and the maximum sample over all phases. Repeated vertex samples count repeatedly. This is a useful analytic-field residual, not a symmetric Hausdorff distance.
+The merge-time T-junction conformance added 52 triangles across Hybrid’s suite and 40 across DC’s; MC needed none. Its measured added-triangle field residual is 0 m at the CSV precision. The full per-case data is in [seams.csv](results/seams.csv).
 
-| Fixture | MC mean / max (cm) | Hybrid mean / max (cm) | DC mean / max (cm) |
-|---|---:|---:|---:|
-| 90° corner | 0.51 / 16.67 | 0.17 / 6.25 | 0.17 / 6.25 |
-| Doorway | 0.99 / 16.67 | 0.41 / 12.50 | 0.41 / 12.50 |
-| One-metre riser | 0.46 / 16.67 | 0.15 / 6.25 | 0.15 / 6.25 |
-| Cliff ledge / overhang | 0.49 / 16.67 | 0.16 / 6.25 | 0.16 / 6.25 |
-| Cave-chamber wall | 0.39 / 1.17 | 0.39 / 1.17 | 0.50 / 4.75 |
+## 2:1 LOD transition results
 
-MC’s worst sharp residual is 16.67 cm at this phase sample, close to the expected 17.68 cm half-diagonal bevel bound. Hybrid/DC reduce the sharp residual while DC-everywhere is rougher on the smooth chamber than either MC path.
+The full gate still fails. Raw fine/coarse contour comparisons stay below the 0.50 m budget, but the transition surface/topology does not close all cases.
 
-Crease split rate counts adjacent triangles with distinct analytic feature labels and face-normal angle above 30°. A split is counted when their average interpolated/vertex normals also differ by more than 30°.
+| Method | Bad cases | Seam-band open edges | Seam-band nonmanifold edges | Worst raw contour mismatch | Worst transition field residual |
+|---|---:|---:|---:|---:|---:|
+| MC | 5 / 625 | 15 | 5 | 0.318199 m | 0.250008 m |
+| Hybrid | 38 / 625 | 4,213 | 47 | 0.158352 m | 1.24975 m |
+| DC | 40 / 625 | 4,465 | 49 | 0.158352 m | 1.96263 m |
 
-| Fixture | MC split rate | Hybrid split rate | DC split rate |
-|---|---:|---:|---:|
-| 90° corner | 11.83% | 99.93% | 99.93% |
-| Doorway | 24.31% | 100.00% | 100.00% |
-| One-metre riser | 12.98% | 99.99% | 99.99% |
-| Cliff ledge / overhang | 15.18% | 99.89% | 99.89% |
-| Cave-chamber wall | no tagged crease | no tagged crease | no tagged crease |
+Failures by fixture: MC has five doorway cases; Hybrid has 25 corner and 13 overhang cases; DC has those same 38 plus two organic-cave cases. Hybrid/DC transition residuals exceed the 0.50 m budget on the corner cases. Some remaining rows have open or nonmanifold seam edges even when the raw contour mismatch is small. The full CSV keeps pre-transition and internal topology counts separate. The unrestricted-cap diagnostic is preserved in [seams_cap_unbounded_diagnostic.csv](results/seams_cap_unbounded_diagnostic.csv).
 
-## Topology and independent borders
+The dedicated sharp cliff crossing case passes all three methods: zero unmatched probes, open edges, and nonmanifold edges. Its maximum raw contour mismatch is 0.249977 m for MC and 0.419411 m for Hybrid/DC; the transition field residual maxima are 0.233333 m and 0.238888 m respectively. See [lod_cliff_crossing.csv](results/lod_cliff_crossing.csv).
 
-The phase meshes themselves have no nonmanifold edges. MC has 0 open-edge meshes in 625 fixture/phase cases. Hybrid and DC each have 36 open-edge meshes in 625, summing to 116 open edges across those cases.
+The remaining Unreal-only checks are actual `UBodySetup` collision cooking/contact, projected pixel error at the game cameras, and runtime task scheduling/upload against the plugin mesher. None of those can repair the standalone topology failures; the topology gate is still the reason to defer Unreal integration.
 
-Independent-border results aggregate 625 fixture/phase cases per method. “Bad” means unmatched seam probes, boundary edges, or nonmanifold edges. No nonmanifold edges were found.
+### Production skirt baseline
 
-| Method | Same-LOD bad cases / 625 | Same-LOD open edges | Same-LOD unmatched probes | LOD0/LOD1 bad cases / 625 | LOD0/LOD1 open edges | LOD0/LOD1 unmatched probes |
+The current plugin skirt depth is `max(1, SkirtCells) × Step × GeometryVoxelSize`; skirts are normal-extruded, double-sided visual strips. With Core’s 25 cm geometry voxel size and the default `SkirtCells = 4`, nominal depth is 1 m at LOD0 and 2 m at LOD1. Project settings can override these defaults. Skirts hide many visual gaps but do not make the neighboring surface topologically watertight. The new transition has not yet replaced that production behavior.
+
+## Surface residual and crease splits
+
+Residual is the absolute field value sampled at triangle vertices, edge midpoints, and centroids; it is not a symmetric Hausdorff distance. Values below average the 625 phase rows per method; maxima are the worst sampled value.
+
+| Method | Mean residual | Worst residual | Tagged crease pairs | Normal split pairs | Split rate on tagged creases | Mean triangles / vertices |
 |---|---:|---:|---:|---:|---:|---:|
-| MC | 0 | 0 | 0 | 625 | 75,494 | 0 |
-| Hybrid | 500 | 85,632 | 3,484 | 625 | 75,794 | 5,819 |
-| DC | 625 | 101,440 | 3,609 | 625 | 75,790 | 6,128 |
+| MC | 0.5664 cm | 16.6670 cm | 10,926 | 1,847 | 16.90% | 3,363.1 / 1,728.8 |
+| Hybrid | 0.2552 cm | 12.5027 cm | 140,876 | 140,806 | 99.95% | 3,365.3 / 3,469.2 |
+| DC | 0.2786 cm | 12.5027 cm | 140,876 | 140,806 | 99.95% | 3,365.8 / 1,985.6 |
 
-MC’s same-LOD contour match is exact in all cases: zero measured contour distance and zero merged open edges. Hybrid passes only the 125 smooth chamber cases; its 500 tagged-shape cases have open edges. DC also fails the chamber border.
+The hybrid keeps untagged/organic components on MC and uses DC for tagged sharp features. It preserves the sharp corner/riser/ledge better than MC in the analytic fixtures, while its feature splits roughly double the vertex count.
 
-Every LOD0/LOD1 case has open boundary edges. For MC, the per-case maximum sampled contour distance has an 18.57 cm median, 26.41 cm 95th percentile, and 31.82 cm worst case; 39 of 625 cases exceed 25 cm. Hybrid has complete contour comparisons in only 130 cases; five of those exceed 25 cm, with a 560.47 cm worst finite comparison. DC has complete contour comparisons in only five cases, with a 560.47 cm worst finite comparison. The large finite outliers and unmatched probes are direct failures, not a pass hidden by averages. The spike has no transition templates, so these results are a transition gate, not a claim that any candidate’s final transition design has been tuned.
+## Sampled native SurfaceWorld cliff
 
-## Cost, determinism, and collision proxy
+The native comparison samples the 8 m patch at 25 cm from the M1 SurfaceWorld manifest (feature type 4, feature `0x9812c26310b90c9`, manifest hash `0x8933693d9560ba9f`). MC and Hybrid emit bit-identical vertex and triangle arrays, with identical mesh hash `0x9d58e0603f1bf9c7`: 2,345 vertices and 4,496 triangles each. This confirms that the hybrid leaves this untagged native patch unchanged.
 
-Each timing uses an already sampled 32³-cell field grid, three mesh builds, and the median build time. Field sampling, Unreal scheduling, upload, collision cooking, and rendering are excluded. All values below average the five fixtures.
+The sampled scalar-field residual is 0.212167 m mean and 16.0068 m max for both MC and Hybrid. This patch is cropped at the 8 m volume boundary and has 192 boundary edges; these values are not a seam result, and the scalar field is not a signed-distance guarantee. DC-everywhere differs (2,247 vertices, 3,961 triangles, 4.57272 m mean / 16.5898 m max, 504 boundary edges and 74 nonmanifold edges). The native CSV is [native_surface.csv](results/native_surface.csv).
 
-| Worker count | MC mean ms/tile | Hybrid mean ms/tile | DC mean ms/tile |
+## Cost and determinism
+
+The timer starts after the 32³ field grid is sampled, measures meshing only, and excludes Unreal scheduling, upload, collision cooking, and rendering. Values below are the median of five fixture medians; W1/W8 use three builds, while W16 uses one timed build because repeated W16 thread creation had caused a host access violation. Hash determinism is still checked at all three worker counts.
+
+| Workers | MC ms/tile | Hybrid ms/tile | DC ms/tile |
 |---:|---:|---:|---:|
-| 1 | 16.308 | 17.375 | 16.269 |
-| 8 | 14.275 | 14.907 | 13.996 |
-| 16 | 14.555 | 15.291 | 14.129 |
+| 1 | 16.316 | 17.534 | 16.417 |
+| 8 | 53.914 | 54.840 | 52.606 |
+| 16 | 86.961 | 90.490 | 89.476 |
 
-At W8, hybrid is 4.4% slower and DC is 2.0% faster than MC. Mean triangle counts are 3,454.4 / 3,456.8 / 3,457.6 for MC / Hybrid / DC. Mean vertex counts are 1,728.8 / 3,469.2 / 1,985.6. Hybrid’s feature-split path therefore roughly doubles output vertices for negligible triangle change.
+All 45 W1/W8/W16 rows match the W1 hash for that method and fixture. The standalone collision proxy copies the render mesh: all hashes match and measured geometry delta is 0 m. This does not test Unreal collision cooking.
 
-All 45 determinism rows (five fixtures × three methods × three worker counts) match the W1 reference for that fixture and method: zero cross-worker hash mismatches. W16 is a 16-worker software pool running with process affinity limited to eight logical CPUs.
+These timings are **not comparable to the optimized production MC mesher**. The harness is a separate STL/map-based implementation with its own worker dispatch and already-sampled grid; the strong slowdown at W8/W16 is further evidence not to use these numbers as a production estimate. They are useful only for comparisons within this harness.
 
-The standalone collision proxy is the same emitted vertex/triangle mesh. All 45 proxy hashes match the visual mesh hash and report 0 m geometry delta. This verifies the candidate mesh handoff only; there is no independent collision simplification, Unreal physics cook, or contact test in round 1.
+## Contact sheet
 
-## Captures
+The [updated offline contact sheet](results/captures/contact_sheet.jpg) is 864 × 1,968 pixels. It contains the five analytic fixtures, the sampled SurfaceWorld cliff, and both LOD seam views, with MC/Hybrid/DC columns. The 24 individual JPEGs are 288 × 246 pixels; all 25 files including the sheet are below 300 KB. No viewer or GPU path was used.
 
-The [contact sheet](results/captures/contact_sheet.jpg) is an offline orthographic rasterization of matched MC, Hybrid, and DC meshes for all five fixtures, plus one LOD seam view per method. It is 864 × 1,476 pixels. The 18 individual captures are 288 × 246 pixels. There are 19 JPEGs including the sheet; all are under 300 KB, and the largest is the 128,260-byte contact sheet. No viewer was launched.
+## Recommendation and round-3 Unreal plan
 
-Capture files:
+Do not select or enable the hybrid in the owner project yet. The same-LOD gate is closed, but the full LOD gate is not. The current Core world hash/default path is untouched.
 
-- [90° corner — MC](results/captures/corner90_MC.jpg), [Hybrid](results/captures/corner90_Hybrid.jpg), [DC](results/captures/corner90_DC.jpg)
-- [Doorway — MC](results/captures/doorway_MC.jpg), [Hybrid](results/captures/doorway_Hybrid.jpg), [DC](results/captures/doorway_DC.jpg)
-- [One-metre riser — MC](results/captures/riser1m_MC.jpg), [Hybrid](results/captures/riser1m_Hybrid.jpg), [DC](results/captures/riser1m_DC.jpg)
-- [Cliff ledge — MC](results/captures/cliff_overhang_MC.jpg), [Hybrid](results/captures/cliff_overhang_Hybrid.jpg), [DC](results/captures/cliff_overhang_DC.jpg)
-- [Cave chamber — MC](results/captures/organic_cave_chamber_MC.jpg), [Hybrid](results/captures/organic_cave_chamber_Hybrid.jpg), [DC](results/captures/organic_cave_chamber_DC.jpg)
-- [LOD seam — MC](results/captures/lodseam_MC.jpg), [Hybrid](results/captures/lodseam_Hybrid.jpg), [DC](results/captures/lodseam_DC.jpg)
+When the standalone LOD gate passes, round 3 should:
 
-## Run ledger and constraints
+1. Add an **opt-in, versioned** recipe such as `WorldAssemblerHybridV1`, default off, with its mesher, feature ownership, transition, and collision settings recorded as part of the version. Keep the existing Core recipe and default hashes unchanged.
+2. Add an Unreal test map with the five analytic fixtures, the sampled SurfaceWorld cliff, and a native Core cave tile. Include independent same-LOD neighbors and a sharp cliff crossing from LOD0 to LOD1. Compare skirts on/off and use matched cameras plus wireframe views.
+3. Cook collision through the real Unreal path. Wait for cooking completion, then run capsule sweeps/walk tests over the doorway, riser, cliff underside, cave wall, and both borders. Check collision/render agreement and recooking after a local edit.
+4. Record mesh and collision cook latency, CPU/memory, triangle/vertex counts, LOD error in pixels at the fixture cameras, and player contact results. Keep MC as the direct baseline and preserve a one-switch rollback to the existing recipe.
+
+## Run ledger and scope
 
 | Run/check | Result |
 |---|---|
-| Final MSVC C++20 build | Passed in 4.42 s, BelowNormal, affinity 0xFF00. |
-| Final phase/cost/determinism/seam run | Passed in 114.208 s; 1,875 phase meshes and 1,875 independent seam cases, BelowNormal, affinity 0xFF00. |
-| Final capture renderer | Passed in 2.61 s, BelowNormal, affinity 0xFF00; 19 files under the 300 KB cap. |
-| Earlier phase run 1 | Exited normally in 31.14 s; exact-zero lattice degeneracies exposed topology defects. |
-| Earlier phase run 2 | Exited normally in 31.11 s after adding the deterministic exact-zero bias; DC still had boundary defects. |
-| Earlier phase run 3 | Exited normally in 35.07 s after splitting disconnected cell patches; remaining boundary defects kept it from acceptance. |
-| Earlier phase run 4 | Exited normally in 36.55 s after making MC endpoint-gradient interpolation explicit; used for normal-split comparison. |
-| Earlier seam run | Exited normally in 74.21 s, but clipped a shared mesh and did not test independently generated borders. It was superseded by the final independent-neighbor seam run. |
-| Tool validation | One early PowerShell parser check used an invalid reference argument. Two later analysis-only PowerShell aggregation commands had syntax errors. All were corrected; none launched a mesher process. One early MSVC environment setup printed a nonfatal vswhere helper warning; compilation succeeded, and the final build emitted no warning. |
+| Final MSVC C++20 build | Passed in 5.44 s, BelowNormal, affinity `0xFF00`. |
+| Full seam run with unrestricted residual-loop caps | Completed in 602.78 s; 83 LOD cases failed. Preserved as `results/seams_cap_unbounded_diagnostic.csv`. |
+| Final full seam run with 0.50 m cap-residual guard | Completed in 601.31 s; same-LOD passed 625/625 for all methods, LOD failures were MC 5, Hybrid 38, DC 40. No crash or guard trip. |
+| Cost/phase/native analysis | Completed in 120.95 s; 1,875 phase rows, 45 determinism rows, native patch comparison. |
+| Final offline renderer | Passed in 3.14 s; 25 JPEGs under the 300 KB cap. |
+| Earlier full seam variants | Completed in 559.32 s and 566.44 s. Both failed earlier same-LOD Hybrid/DC cases (36/625 each); superseded by the final T-junction conformance pass. |
+| Focused transition prototypes | Completed within seconds. Earlier MC doorway variants left 64, then 3–4 open edges; whole-mesh endpoint snapping introduced nonmanifold edges. Those variants were rejected. The bounded residual-loop cap closes this focused doorway case, but the full LOD matrix still fails. |
+| Earlier native halo diagnostic | An initial process exited `0xC0000005`; an AddressSanitizer launch first failed `0xC0000135` because its runtime DLL was unavailable. After using the Visual Studio runtime path, ASan found the halo index overflow; the indexing was fixed, and subsequent harness runs completed. |
+| W16 timing diagnostic | Repeated creation/timing of 16 OS workers caused a host access violation. W16 now uses one timed build; hash determinism remains checked. |
+| Aggregation tools | Two PowerShell summary attempts had query errors, including a missing `vertices` field in `phase_sweep.csv`; corrected queries ran without launching a mesher. No `0xC0000142` retry was needed. |
 
-Every final build/test/render process used BelowNormal priority and affinity 0xFF00, limiting it to eight of the 16 logical processors. The build/test/render scripts enforce an 8 GB private-memory guard and 15-minute timeout. No process hit either limit, crashed, or needed a 0xC0000142 retry. The earlier phase runs above exited normally; their topology/seam measurements failed or were superseded as noted. No viewer or owner editor was opened. No owner project was built and no .uasset was touched.
+Every final build, mesher, analysis, and renderer process ran BelowNormal with affinity `0xFF00`; the scripts enforce an 8 GB private-memory limit and 15-minute timeout. Peak observed mesher private memory was under 0.2 GB. No final process crashed, exceeded a limit, or needed a retry.
 
-## Files added for the spike
+All edits and outputs are under `Plugins/VoxelForge/Standalone/Research/WorldAssemblerM2`, plus this dialogue log. No `Source/` file, Core source, owner project file, `.uasset`, or editor was touched. No commit, push, or stash was made.
 
-New implementation and launch files:
+## Files changed and new source files
 
-- [SharpMesherSpike.cpp](SharpMesherSpike.cpp)
-- [BuildSharpMesherSpike.ps1](BuildSharpMesherSpike.ps1)
-- [RunSharpMesherSpike.ps1](RunSharpMesherSpike.ps1)
-- [RenderSharpMesherCaptures.ps1](RenderSharpMesherCaptures.ps1)
-- [RenderSharpMesherCaptures.py](RenderSharpMesherCaptures.py)
+Updated existing standalone files: [SharpMesherSpike.cpp](SharpMesherSpike.cpp), [BuildSharpMesherSpike.ps1](BuildSharpMesherSpike.ps1), [RunSharpMesherSpike.ps1](RunSharpMesherSpike.ps1), and [RenderSharpMesherCaptures.py](RenderSharpMesherCaptures.py). Updated this report and appended the M2 round-2 dialogue entry.
 
-The report, CSV measurements, exported OBJ meshes, offline captures, executable/object build outputs, and run logs are also in this WorldAssemblerM2 directory. No files under Source were changed.
+**New source files this round: none.** CSVs, OBJ meshes, JPEG captures, logs, and local build outputs are generated research artifacts; none were committed.

Standalone/Research/WorldAssemblerM2/RenderSharpMesherCaptures.py

@@ -19,6 +19,7 @@ PIECES = (
     ("riser1m", "one metre riser"),
     ("cliff_overhang", "cliff ledge / overhang"),
     ("organic_cave_chamber", "organic cave chamber wall"),
+    ("native_surface_cliff", "sampled SurfaceWorld cliff"),
 )
 WIDTH, HEIGHT = 288, 216
 BG = (239, 242, 244)
@@ -56,14 +57,26 @@ def read_obj(path: Path):
     return vertices, normals, faces
 
 
-def project_mesh(vertices, faces, seam=False):
+def project_mesh(vertices, faces, seam=False, target=None):
     # One view is reused for every candidate in a row: azimuth 38°, elevation 27°.
-    target = (0.0, 0.0, 0.0)
+    if target is None:
+        if vertices:
+            bounds_min = tuple(min(v[i] for v in vertices) for i in range(3))
+            bounds_max = tuple(max(v[i] for v in vertices) for i in range(3))
+            target = tuple((bounds_min[i] + bounds_max[i]) * 0.5 for i in range(3))
+        else:
+            target = (0.0, 0.0, 0.0)
     view_dir = normalize((8.0, -10.0, 7.0))
     forward = tuple(-c for c in view_dir)
     right = normalize(cross(forward, (0.0, 0.0, 1.0)))
     up = normalize(cross(right, forward))
-    scale = 20.2
+    projected_bounds = []
+    for point in vertices:
+        rel = tuple(point[i] - target[i] for i in range(3))
+        projected_bounds.append((dot(rel, right), dot(rel, up)))
+    span_x = max((point[0] for point in projected_bounds), default=0.0) - min((point[0] for point in projected_bounds), default=0.0)
+    span_y = max((point[1] for point in projected_bounds), default=0.0) - min((point[1] for point in projected_bounds), default=0.0)
+    scale = min(20.2, 0.84 * min((WIDTH - 24) / max(span_x, 1.0e-6), (HEIGHT - 24) / max(span_y, 1.0e-6)))
     projected = []
     for p in vertices:
         rel = tuple(p[i] - target[i] for i in range(3))
@@ -102,7 +115,10 @@ def raster(path: Path, color_by_x=False):
             for i in range(1, len(clipped) - 1):
                 clipped_faces.append(((first, first), (first + i, first + i), (first + i + 1, first + i + 1)))
         vertices, normals, faces = clipped_vertices, clipped_normals, clipped_faces
-    projected = project_mesh(vertices, faces, color_by_x)
+    bounds_min = tuple(min(v[i] for v in vertices) for i in range(3))
+    bounds_max = tuple(max(v[i] for v in vertices) for i in range(3))
+    target = tuple((bounds_min[i] + bounds_max[i]) * 0.5 for i in range(3))
+    projected = project_mesh(vertices, faces, color_by_x, target)
     pixels = Image.new("RGB", (WIDTH, HEIGHT), BG)
     zbuf = [float("inf")] * (WIDTH * HEIGHT)
     px = pixels.load()
@@ -146,7 +162,7 @@ def raster(path: Path, color_by_x=False):
         draw = ImageDraw.Draw(pixels)
         # Project a visible segment on the LOD boundary plane, x=0.
         seam_world = [(-0.0, y, z) for y, z in ((-4, -4), (4, -4), (4, 4), (-4, 4), (-4, -4))]
-        seam_points = project_mesh(seam_world, [], True)
+        seam_points = project_mesh(seam_world, [], True, target)
         draw.line([(p[0], p[1]) for p in seam_points], fill=(181, 55, 49), width=2)
     return pixels
 
@@ -174,14 +190,14 @@ def main():
         captures.append(row)
     seam_row = []
     for method in METHODS:
-        obj = RESULTS / "meshes" / f"lodseam_cliff_overhang_{method}.obj"
-        image = capture_title(raster(obj, color_by_x=True), "LOD0 to LOD1 cliff seam", f"{method} | fine left, coarse right, x=0 seam")
-        path = CAPTURES / f"lodseam_{method}.jpg"
+        obj = RESULTS / "meshes" / f"lodseam_cliff_crossing_{method}.obj"
+        image = capture_title(raster(obj, color_by_x=True), "Sharp cliff across LOD border", f"{method} | LOD0 left, LOD1 right, x=0")
+        path = CAPTURES / f"lodseam_cliff_crossing_{method}.jpg"
         image.save(path, quality=86, optimize=True)
         seam_row.append(image)
     captures.append(seam_row)
 
-    sheet = Image.new("RGB", (WIDTH * 3, (HEIGHT + 30) * 6), (221, 227, 230))
+    sheet = Image.new("RGB", (WIDTH * 3, (HEIGHT + 30) * len(captures)), (221, 227, 230))
     draw = ImageDraw.Draw(sheet)
     for row_index, row in enumerate(captures):
         for col_index, image in enumerate(row):

Standalone/Research/WorldAssemblerM2/RunSharpMesherSpike.ps1

@@ -1,6 +1,8 @@
 [CmdletBinding()]
 param(
-    [ValidateRange(2,5)][int]$PhaseCount = 5
+    [ValidateRange(2,5)][int]$PhaseCount = 5,
+    [ValidateSet('all','seams','native','analysis')][string]$Mode = 'all',
+    [ValidateRange(0,1875)][int]$SeamRowLimit = 0
 )
 
 $ErrorActionPreference = 'Stop'
@@ -23,7 +25,9 @@ do {
     Remove-Item -LiteralPath $Stdout, $Stderr -Force -ErrorAction SilentlyContinue
     $Info = [Diagnostics.ProcessStartInfo]::new()
     $Info.FileName = $Exe
-    $Info.Arguments = ('--out="{0}" --phase-count={1}' -f $OutDir, $PhaseCount)
+    $ModeArgument = if ($Mode -eq 'seams') { ' --seams-only' } elseif ($Mode -eq 'native') { ' --native-only' } elseif ($Mode -eq 'analysis') { ' --analysis-only' } else { '' }
+    $RowLimitArgument = if ($SeamRowLimit -gt 0) { ' --seam-row-limit={0}' -f $SeamRowLimit } else { '' }
+    $Info.Arguments = ('--out="{0}" --phase-count={1}{2}{3}' -f $OutDir, $PhaseCount, $ModeArgument, $RowLimitArgument)
     $Info.WorkingDirectory = [IO.Path]::GetFullPath((Join-Path $WorkDir '..\..'))
     $Info.UseShellExecute = $false
     $Info.CreateNoWindow = $true

Standalone/Research/WorldAssemblerM2/results/cost.csv

@@ -1,46 +1,46 @@
 piece,method,workers,cell_count,triangles,vertices,mesh_ms_median_3,mesh_hash,collision_proxy_hash,collision_geometry_delta_m
-corner90,MC,1,32768,3192,1598,16.5302,0x3e35202e741326da,0x3e35202e741326da,0
-corner90,MC,8,32768,3192,1598,14.1565,0x3e35202e741326da,0x3e35202e741326da,0
-corner90,MC,16,32768,3192,1598,14.5744,0x3e35202e741326da,0x3e35202e741326da,0
-corner90,Hybrid,1,32768,3196,3473,17.3756,0x1c68ed55a97a2b70,0x1c68ed55a97a2b70,0
-corner90,Hybrid,8,32768,3196,3473,14.7298,0x1c68ed55a97a2b70,0x1c68ed55a97a2b70,0
-corner90,Hybrid,16,32768,3196,3473,15.1832,0x1c68ed55a97a2b70,0x1c68ed55a97a2b70,0
-corner90,DC,1,32768,3196,1875,16.346,0x27eb83e4bcb5d532,0x27eb83e4bcb5d532,0
-corner90,DC,8,32768,3196,1875,13.5541,0x27eb83e4bcb5d532,0x27eb83e4bcb5d532,0
-corner90,DC,16,32768,3196,1875,13.9794,0x27eb83e4bcb5d532,0x27eb83e4bcb5d532,0
-doorway,MC,1,32768,2172,1086,15.0354,0x5091c48df9516232,0x5091c48df9516232,0
-doorway,MC,8,32768,2172,1086,13.7949,0x5091c48df9516232,0x5091c48df9516232,0
-doorway,MC,16,32768,2172,1086,13.9519,0x5091c48df9516232,0x5091c48df9516232,0
-doorway,Hybrid,1,32768,2172,2462,15.8758,0xc70ca49841d4ad46,0xc70ca49841d4ad46,0
-doorway,Hybrid,8,32768,2172,2462,14.137,0xc70ca49841d4ad46,0xc70ca49841d4ad46,0
-doorway,Hybrid,16,32768,2172,2462,14.5053,0xc70ca49841d4ad46,0xc70ca49841d4ad46,0
-doorway,DC,1,32768,2172,1376,15.0068,0x7ec18c54d9af2487,0x7ec18c54d9af2487,0
-doorway,DC,8,32768,2172,1376,13.2934,0x7ec18c54d9af2487,0x7ec18c54d9af2487,0
-doorway,DC,16,32768,2172,1376,13.2488,0x7ec18c54d9af2487,0x7ec18c54d9af2487,0
-riser1m,MC,1,32768,4428,2216,17.6744,0x930603791a29a779,0x930603791a29a779,0
-riser1m,MC,8,32768,4428,2216,15.0862,0x930603791a29a779,0x930603791a29a779,0
-riser1m,MC,16,32768,4428,2216,15.501,0x930603791a29a779,0x930603791a29a779,0
-riser1m,Hybrid,1,32768,4432,4775,19.222,0x7a80c8099ed5e2df,0x7a80c8099ed5e2df,0
-riser1m,Hybrid,8,32768,4432,4775,15.9639,0x7a80c8099ed5e2df,0x7a80c8099ed5e2df,0
-riser1m,Hybrid,16,32768,4432,4775,16.2443,0x7a80c8099ed5e2df,0x7a80c8099ed5e2df,0
-riser1m,DC,1,32768,4432,2559,17.6231,0x7a58ef3dd552662f,0x7a58ef3dd552662f,0
-riser1m,DC,8,32768,4432,2559,15.5117,0x7a58ef3dd552662f,0x7a58ef3dd552662f,0
-riser1m,DC,16,32768,4432,2559,15.5445,0x7a58ef3dd552662f,0x7a58ef3dd552662f,0
-cliff_overhang,MC,1,32768,5036,2520,18.5265,0x1881bd75ddc7e7de,0x1881bd75ddc7e7de,0
-cliff_overhang,MC,8,32768,5036,2520,15.2582,0x1881bd75ddc7e7de,0x1881bd75ddc7e7de,0
-cliff_overhang,MC,16,32768,5036,2520,15.3717,0x1881bd75ddc7e7de,0x1881bd75ddc7e7de,0
-cliff_overhang,Hybrid,1,32768,5040,5412,19.8127,0x985b8497adfe9dec,0x985b8497adfe9dec,0
-cliff_overhang,Hybrid,8,32768,5040,5412,15.9717,0x985b8497adfe9dec,0x985b8497adfe9dec,0
-cliff_overhang,Hybrid,16,32768,5040,5412,16.4467,0x985b8497adfe9dec,0x985b8497adfe9dec,0
-cliff_overhang,DC,1,32768,5040,2892,18.232,0x4723adced541eab2,0x4723adced541eab2,0
-cliff_overhang,DC,8,32768,5040,2892,14.6485,0x4723adced541eab2,0x4723adced541eab2,0
-cliff_overhang,DC,16,32768,5040,2892,14.7275,0x4723adced541eab2,0x4723adced541eab2,0
-organic_cave_chamber,MC,1,32768,2444,1224,13.7729,0x50031a0a691ec6f4,0x50031a0a691ec6f4,0
-organic_cave_chamber,MC,8,32768,2444,1224,13.0782,0x50031a0a691ec6f4,0x50031a0a691ec6f4,0
-organic_cave_chamber,MC,16,32768,2444,1224,13.3739,0x50031a0a691ec6f4,0x50031a0a691ec6f4,0
-organic_cave_chamber,Hybrid,1,32768,2444,1224,14.5881,0x50031a0a691ec6f4,0x50031a0a691ec6f4,0
-organic_cave_chamber,Hybrid,8,32768,2444,1224,13.732,0x50031a0a691ec6f4,0x50031a0a691ec6f4,0
-organic_cave_chamber,Hybrid,16,32768,2444,1224,14.0734,0x50031a0a691ec6f4,0x50031a0a691ec6f4,0
-organic_cave_chamber,DC,1,32768,2448,1226,14.1388,0x317a60749cc26f6a,0x317a60749cc26f6a,0
-organic_cave_chamber,DC,8,32768,2448,1226,12.971,0x317a60749cc26f6a,0x317a60749cc26f6a,0
-organic_cave_chamber,DC,16,32768,2448,1226,13.1444,0x317a60749cc26f6a,0x317a60749cc26f6a,0
+corner90,MC,1,32768,3192,1598,16.3157,0x3e35202e741326da,0x3e35202e741326da,0
+corner90,MC,8,32768,3192,1598,53.6312,0x3e35202e741326da,0x3e35202e741326da,0
+corner90,MC,16,32768,3192,1598,86.3833,0x3e35202e741326da,0x3e35202e741326da,0
+corner90,Hybrid,1,32768,3196,3473,17.5341,0x1c68ed55a97a2b70,0x1c68ed55a97a2b70,0
+corner90,Hybrid,8,32768,3196,3473,54.4508,0x1c68ed55a97a2b70,0x1c68ed55a97a2b70,0
+corner90,Hybrid,16,32768,3196,3473,88.7485,0x1c68ed55a97a2b70,0x1c68ed55a97a2b70,0
+corner90,DC,1,32768,3196,1875,16.4166,0x27eb83e4bcb5d532,0x27eb83e4bcb5d532,0
+corner90,DC,8,32768,3196,1875,50.7349,0x27eb83e4bcb5d532,0x27eb83e4bcb5d532,0
+corner90,DC,16,32768,3196,1875,89.7405,0x27eb83e4bcb5d532,0x27eb83e4bcb5d532,0
+doorway,MC,1,32768,2172,1086,15.0271,0x5091c48df9516232,0x5091c48df9516232,0
+doorway,MC,8,32768,2172,1086,53.9143,0x5091c48df9516232,0x5091c48df9516232,0
+doorway,MC,16,32768,2172,1086,86.9611,0x5091c48df9516232,0x5091c48df9516232,0
+doorway,Hybrid,1,32768,2172,2462,16.808,0xc70ca49841d4ad46,0xc70ca49841d4ad46,0
+doorway,Hybrid,8,32768,2172,2462,51.3028,0xc70ca49841d4ad46,0xc70ca49841d4ad46,0
+doorway,Hybrid,16,32768,2172,2462,90.4899,0xc70ca49841d4ad46,0xc70ca49841d4ad46,0
+doorway,DC,1,32768,2172,1376,14.9295,0x7ec18c54d9af2487,0x7ec18c54d9af2487,0
+doorway,DC,8,32768,2172,1376,50.7911,0x7ec18c54d9af2487,0x7ec18c54d9af2487,0
+doorway,DC,16,32768,2172,1376,89.4764,0x7ec18c54d9af2487,0x7ec18c54d9af2487,0
+riser1m,MC,1,32768,4428,2216,17.0044,0x930603791a29a779,0x930603791a29a779,0
+riser1m,MC,8,32768,4428,2216,55.4369,0x930603791a29a779,0x930603791a29a779,0
+riser1m,MC,16,32768,4428,2216,88.7519,0x930603791a29a779,0x930603791a29a779,0
+riser1m,Hybrid,1,32768,4432,4775,18.335,0x7a80c8099ed5e2df,0x7a80c8099ed5e2df,0
+riser1m,Hybrid,8,32768,4432,4775,54.8397,0x7a80c8099ed5e2df,0x7a80c8099ed5e2df,0
+riser1m,Hybrid,16,32768,4432,4775,89.4327,0x7a80c8099ed5e2df,0x7a80c8099ed5e2df,0
+riser1m,DC,1,32768,4432,2559,17.3764,0x7a58ef3dd552662f,0x7a58ef3dd552662f,0
+riser1m,DC,8,32768,4432,2559,53.7095,0x7a58ef3dd552662f,0x7a58ef3dd552662f,0
+riser1m,DC,16,32768,4432,2559,89.3463,0x7a58ef3dd552662f,0x7a58ef3dd552662f,0
+cliff_overhang,MC,1,32768,5036,2520,17.7295,0x1881bd75ddc7e7de,0x1881bd75ddc7e7de,0
+cliff_overhang,MC,8,32768,5036,2520,54.7049,0x1881bd75ddc7e7de,0x1881bd75ddc7e7de,0
+cliff_overhang,MC,16,32768,5036,2520,88.8038,0x1881bd75ddc7e7de,0x1881bd75ddc7e7de,0
+cliff_overhang,Hybrid,1,32768,5040,5412,20.57,0x985b8497adfe9dec,0x985b8497adfe9dec,0
+cliff_overhang,Hybrid,8,32768,5040,5412,55.3158,0x985b8497adfe9dec,0x985b8497adfe9dec,0
+cliff_overhang,Hybrid,16,32768,5040,5412,92.9896,0x985b8497adfe9dec,0x985b8497adfe9dec,0
+cliff_overhang,DC,1,32768,5040,2892,17.9445,0x4723adced541eab2,0x4723adced541eab2,0
+cliff_overhang,DC,8,32768,5040,2892,53.6535,0x4723adced541eab2,0x4723adced541eab2,0
+cliff_overhang,DC,16,32768,5040,2892,91.0395,0x4723adced541eab2,0x4723adced541eab2,0
+organic_cave_chamber,MC,1,32768,2444,1224,13.1379,0x50031a0a691ec6f4,0x50031a0a691ec6f4,0
+organic_cave_chamber,MC,8,32768,2444,1224,53.0874,0x50031a0a691ec6f4,0x50031a0a691ec6f4,0
+organic_cave_chamber,MC,16,32768,2444,1224,86.6699,0x50031a0a691ec6f4,0x50031a0a691ec6f4,0
+organic_cave_chamber,Hybrid,1,32768,2444,1224,14.9431,0x50031a0a691ec6f4,0x50031a0a691ec6f4,0
+organic_cave_chamber,Hybrid,8,32768,2444,1224,55.2694,0x50031a0a691ec6f4,0x50031a0a691ec6f4,0
+organic_cave_chamber,Hybrid,16,32768,2444,1224,95.9217,0x50031a0a691ec6f4,0x50031a0a691ec6f4,0
+organic_cave_chamber,DC,1,32768,2448,1226,13.2164,0x317a60749cc26f6a,0x317a60749cc26f6a,0
+organic_cave_chamber,DC,8,32768,2448,1226,52.6061,0x317a60749cc26f6a,0x317a60749cc26f6a,0
+organic_cave_chamber,DC,16,32768,2448,1226,86.348,0x317a60749cc26f6a,0x317a60749cc26f6a,0

Standalone/Research/WorldAssemblerM2/results/lod_cliff_crossing.csv

@@ -0,0 +1,4 @@
+method,phase_x_m,phase_y_m,phase_z_m,contour_expected,unmatched_probes,contour_mean_m,contour_max_m,boundary_edges,nonmanifold_edges,edges_before,nonmanifold_before,transition_triangles,paired_loops,capped_loops,unmatched_loops,transition_surface_max_m,fine_segments,coarse_segments
+MC,0.25,0.1,0.1,true,0,0.11871,0.249977,0,0,78,0,234,1,0,0,0.233333,52,26
+Hybrid,0.25,0.1,0.1,true,0,0.0929318,0.419411,0,0,82,0,246,1,0,0,0.238888,56,26
+DC,0.25,0.1,0.1,true,0,0.0929318,0.419411,0,0,82,0,246,1,0,0,0.238888,56,26

Standalone/Research/WorldAssemblerM2/results/lod_cliff_crossing_unbounded_diagnostic.csv

@@ -0,0 +1,4 @@
+method,phase_x_m,phase_y_m,phase_z_m,contour_expected,unmatched_probes,contour_mean_m,contour_max_m,boundary_edges,nonmanifold_edges,edges_before,nonmanifold_before,transition_triangles,paired_loops,capped_loops,unmatched_loops,transition_surface_max_m,fine_segments,coarse_segments
+MC,0.25,0.1,0.1,true,0,0.11871,0.249977,0,0,78,0,234,1,0,0,0.233333,52,26
+Hybrid,0.25,0.1,0.1,true,0,0.0929318,0.419411,0,0,82,0,246,1,0,0,0.238888,56,26
+DC,0.25,0.1,0.1,true,0,0.0929318,0.419411,0,0,82,0,246,1,0,0,0.238888,56,26

Standalone/Research/WorldAssemblerM2/results/native_surface.csv

@@ -0,0 +1,4 @@
+method,manifest_hash,feature_id,feature_type,grid_cells,cell_size_m,origin_x_m,origin_y_m,origin_z_m,iso_probe_z_m,exactly_same_as_mc,mean_abs_field_residual_m,max_abs_field_residual_m,triangles,vertices,boundary_edges,nonmanifold_edges,hash
+MC,0x8933693d9560ba9f,0x9812c26310b90c9,4,32768,0.25,-172,101,-449.239,-445.239,true,0.212167,16.0068,4496,2345,192,0,0x9d58e0603f1bf9c7
+Hybrid,0x8933693d9560ba9f,0x9812c26310b90c9,4,32768,0.25,-172,101,-449.239,-445.239,true,0.212167,16.0068,4496,2345,192,0,0x9d58e0603f1bf9c7
+DC,0x8933693d9560ba9f,0x9812c26310b90c9,4,32768,0.25,-172,101,-449.239,-445.239,false,4.57272,16.5898,3961,2247,504,74,0xd9a992278ffa1a64