# World assembler M1 report

M1 has four implementation rounds. The gates at the end of the milestone remain the agreed
two-biome SurfaceWorld in the owner's game, including coast, cliff/overhang, cap and a walkable
route; conservative bound audits; route sweep; identical evaluator hashes at W1/W8/W16; separate
local query/collision readiness and full-view timings; faster matched workload than the 23.085 s
legacy bridge; and server field queries that do not depend on render meshes. The approximately
1.57 s whole-view aim (2 × the 0.785 s cave-only Core measurement) is an aim, not an acceptance gate.

## Round 1 of 4 — native foundations

- Define the fixed-scale, versioned, hashed recipe and shipped-plan payload, including the Core
  field-block contract and explicit field channels.
- Add a brute-force interval audit with a deliberately false bound as a negative control.
- Implement the first native `Heightfield2D` block with biome-map input and compare it with the
  SurfaceWorld legacy bridge in the standalone viewer.
- Record current hashes, timings, audit results and a small owner/native capture pair. This round
  establishes a heightfield baseline; it does not claim the final two-biome/coast/cliff/route gate.

## Round 2 of 4 — complete the surface recipe

- Add output-space biome blending, coast and beach shaping, cap detail, cliffs and bounded 3D
  overhang exceptions with stable feature IDs and certified influence bounds.
- Keep unknown or intersecting exception intervals on the evaluation path. Expand the brute-force
  audit across biome borders, cliffs, caps, negative coordinates and exception bounds.
- Measure surface field query cost separately from cave compilation and full-view rendering; tune
  caches only after the workload and cache identity are fixed.

## Round 3 of 4 — route and query readiness

- Ship the finite-strate plan with route points, support constraints and stable IDs. Sweep the actual
  player capsule over the final composed field and repair/reject any failing candidate.
- Verify W1/W8/W16 evaluator hashes, route clearance/support and deterministic plan serialization.
- Keep the capsule-swept, supported route valid through generation and automatic/scripted changes.
  Player carve/fill edits are unrestricted and may break or plug the route. Seas and rivers stay fixed
  for the season, with shore behavior under edits measured separately.
- Report local field-query and collision readiness separately from render mesh readiness, and show
  a server-side field query path that does not build or require render meshes.

## Round 4 of 4 — Unreal delivery and owner review

- Import the reviewed manifest into the season asset/content hash path and connect the native Core
  evaluator behind `bUseVoxelForgeCore`, preserving the legacy path when the flag is off.
- Build only the isolated BuildHost target here; the owner builds the project. Review the two-biome
  surface and route in-game, then publish matched workload timings, hashes, audit logs and captures.
- Close every M1 gate or name the failed gate, its evidence and the additional repair round needed.

## Round 1 results

### Deliverables

- Added the public recipe, shipped-plan, hash, channel, block-contract, interval, influence and
  detail-envelope types in `Standalone/Core/include/VoxelForgeCore/VoxelForgeCore.h`. Recipe and
  evaluator schemas are version 1. All recipe, plan, feature, route and field coordinates use signed
  1/256-voxel integers; the plugin's Core voxel remains 25 cm.
- Added manifest parse/finalize/validate/serialize and canonical FNV-1a 64 hashing in
  `Standalone/Core/src/WorldAssemblerInternal.h`. Fields hash in declared order as little-endian
  4/8-byte words. Hashes are 16 lowercase hex digits; JSON key order and whitespace are ignored.
  The optional owner-snapshot `world_assembly` field matches the payload shape planned for the
  season manifest. The current review artifact is
  [`round1-manifest.json`](Research/WorldAssemblerM1/round1-manifest.json); season asset/hash-path
  integration remains for round 4.
- Added native `Heightfield2D`: deterministic warped Voronoi biome selection with Q16 border blend,
  fixed integer profile noise, ground and cap heights, signed density (`negative = solid`), declared
  channels, a conservative global interval, unbounded XY/finite-stratum-Z influence and an explicit
  detail envelope. The current block reads `biome` and writes `height` and `rock`. Water, route and
  surface-tag channels are declared for later blocks, not yet emitted by this block.
- Connected that block to native Core density queries and added the standalone audit/viewer switches.
  `API.md` documents the current data format and its limits.

### Sample manifest and hashes

The viewer builds a sample from the owner's `type_4_SurfaceWorld.json` probe: one finite strate
(index 1, chunk Z -16 through -79), two synthetic stable biome IDs (4097 and 4098), no planned
features, and no route points yet. The compact manifest is 972 bytes.

| Content | Hash |
|---|---|
| Recipe | `5cc6cfb49073d366` |
| Plan | `9aa8b4c29a69233a` |
| Manifest | `c87ae279b0e26f53` |
| Heightfield sample stream, 4096 points | `fae2721c052aec5c` |

The sample block reports influence Z `[-2528, -480]` voxels, maximum displacement envelope
`247` voxels, and minimum feature size `25` voxels. These prototype ranges are not the final
composer-supported recipe envelope.

### Bounds and determinism audit

The brute-force audit tested 256 randomized boxes with a 3×3×3 sample grid per box (6,912 points).
It found zero missed bounds and zero unknown bounds. Its deliberately false one-sided interval was
rejected, so the negative control passed. This is evidence for the current Heightfield2D
implementation and audit path, not a proof for future field blocks or the final cliff/overhang
composition.

The 4,096-point evaluator output hash matched at W1, W8 and W16 (`fae2721c052aec5c`). The timing
scope was point evaluation only: W1 2.059 ms, W8 6.851 ms, W16 12.626 ms. W8 and W16 were slower
on this small batch, likely from thread-startup overhead; no parallel speedup was measured. These
numbers are not a full view or tile benchmark.

### Legacy comparison and captures

For the same 4,096 points, the direct legacy density query took 62.115 ms. The prototype's mean
absolute density error was 274.0383 voxels, maximum error 841.4257 voxels, with 2,261 sign
mismatches (55.2%). The prototype is therefore not yet a parity replacement for the legacy field.
The current biome map and two-profile output need further shaping against the reference.

The small top-down pair uses the same 3200-voxel XY span and one color ramp fitted to the observed
owner and native heights together (range `[-2273.12, -1410.26]` voxels): owner `GetSurfaceHeightAt`
reference and native Heightfield2D ground height. Each JPEG is below 6 KB.

| Owner reference | Native prototype |
|---|---|
| ![Owner SurfaceWorld height reference](Research/WorldAssemblerM1/owner-reference-height.jpg) | ![Native Heightfield2D prototype](Research/WorldAssemblerM1/native-prototype-height.jpg) |

The pair shows a large visible mismatch; it is a height-map comparison, not an in-game render. A
separate D3D window-backbuffer capture attempt was invalid: both viewer windows reported
`DXGI_STATUS_OCCLUDED`, the saved backbuffers were black, and the native prototype produced zero
mesh vertices/indices. The reduced diagnostic images were inspected only after downscaling. Do not
use those D3D files as visual evidence.

### Query, collision and view readiness

The audit compiled a Core world around the sample heightfield, queried 45 positions through
`World::densityAt`, and compared them with direct Heightfield2D evaluation. Maximum error was zero;
the sample Core compile took 35.608 ms; no tile mesh was generated
(`render_meshes_generated=0`). This verifies the local Core field-query path without render meshes
for this sample. It does not yet verify a dedicated-server build or the Unreal adapter.

The no-manifest cave Core path also passed a constrained regression smoke on the existing
`type_3_Maze.json` fixture: the 5,642-point walkability audit passed, all 27 player-neighborhood
tiles and all 64 requested LOD0 tiles generated, and full-detail readiness was 0.157 s at W16.
The shape compile was 0.100 s. This small 64-tile LOD0 run confirms the additive no-plan path still
works; it is not the 23.085 s matched workload or the 0.785 s cave-only whole-view baseline.

Collision cooking is not available in the standalone audit and was not measured. Full-view time was
also not measured by audit mode. Earlier small-view D3D attempt timings (owner 0.236 s, native
0.309 s) are not a valid full-view comparison because presentation was occluded and the native
view had no geometry. The 23.085 s matched-workload gate remains open. The ~1.57 s aim remains
reasonable, but round 1 has no valid full-view evidence to support or reject it.

## Round 2 results

### Round 1 mismatch diagnosis

Round 1 was structurally underfit, not mis-scaled or shifted by a constant height datum. The sample
used two synthetic biome profiles (IDs 4097 and 4098) and a reduced height model. The owner export
uses four resolved surface profiles and relief/moisture climate ranges; the baseline also omitted
the mountain and relief response, height warp, output-space profile blend, coast/beach and cliff
shaping, and per-biome cap detail added in evaluator 2. Both sides use 25 cm voxels, and the current
4,096-column check finds only a -1.366-voxel mean height offset. The owner and Core biome IDs now match on all 4,096
diagnostic columns. These measurements point to missing structure and profile assignment rather
than a unit conversion, datum offset, detail-noise phase, or biome-ID selection error.

This round changed those terms as a group, so the before/after result does not isolate each term's
individual contribution. On the same 4,096 density-query points, mean absolute error fell from
274.0383 to 17.2262 voxels, maximum density error from 841.4257 to 392.4136 voxels, and sign
mismatches from 2,261/4,096 (55.2%) to 743/4,096 (18.14%). The separate 4,096-column height
diagnostic now reports MAE 13.060 voxels, maximum error 203.728 voxels, correlation 0.96496 and
linear-fit slope 0.95136. Residual peaks and sign errors remain visible; this is not parity.

### Evaluator, manifest and audit

Evaluator 2 keeps schema 1 and fixed signed 1/256-voxel units while adding deterministic
climate-based assignment across the owner's four profiles, output-space ground and cap blending,
per-profile relief/height warp/beach/cliff/cap settings, fixed-season water outputs, and stable-ID
bounded 3D overhang exceptions. Player carve/fill edits remain unrestricted; route constraints only
apply to automatic system generation or changes. This sample has one bounded exception
(`09812c26310b90c9`) and no route yet; route planning and capsule sweep remain round 3.

The evaluator-v2 review manifest is 4,514 bytes. Recipe hash is `dbe949967c0dfbce`, plan hash is
`165a00c4a77ebae0`, and manifest hash is `203d7043158069f6`. The 4,096-sample evaluator hash is
`c5e0371612e927af` at W1, W8 and W16. Bounds audit passed with 298 boxes and 8,046 points: zero
missed and zero unknown bounds; 16 biome-border boxes, 16 cliff boxes, 9 cap boxes, 248
negative-coordinate boxes, and one exception box with 27 exception samples. The deliberately
wrong one-sided bound was detected.

The final interval audit followed one failed audit with 102 missed bounds. Inspection found the cap
range was overwritten by a global plan range and that plateau/beach and cliff envelopes were
incomplete. Those envelopes were corrected before the final run. The current result is a sampled
audit of this evaluator and recipe, not a mathematical proof for arbitrary future inputs.

### Matched 3D captures

Each pair uses the same camera for owner and native Core, with full-detail tiles ready before
capture. Images are 640×400 JPEGs; each file is 9,089–17,961 bytes. The native surface, border and
coast pairs broadly agree in silhouette. The cliff pair shows a remaining large difference: the
owner has an extreme noisy overhang, while the prototype currently emits the bounded, smoother
shelf. Water height/fill is emitted as a field sample, but a water overlay mesh is not implemented,
so the coast captures do not show rendered water.

| Site and shared viewer camera (x, y, z; yaw, pitch) | Owner reference | Native Core |
|---|---|---|
| Surface `(0, -35, -487.943; 0, -22)` | ![Surface owner reference](Research/WorldAssemblerM1/round2/captures/surface-owner.jpg) | ![Surface native Core](Research/WorldAssemblerM1/round2/captures/surface-native.jpg) |
| Biome border `(128, -243, -492.912; 0, -22)` | ![Biome border owner reference](Research/WorldAssemblerM1/round2/captures/border-owner.jpg) | ![Biome border native Core](Research/WorldAssemblerM1/round2/captures/border-native.jpg) |
| Coast `(336, -67, -477.755; 0, -22)` | ![Coast owner reference](Research/WorldAssemblerM1/round2/captures/coast-owner.jpg) | ![Coast native Core](Research/WorldAssemblerM1/round2/captures/coast-native.jpg) |
| Cliff `(-168, 70, -445.712; 0, 34)` | ![Cliff owner reference](Research/WorldAssemblerM1/round2/captures/cliff-owner.jpg) | ![Cliff native Core](Research/WorldAssemblerM1/round2/captures/cliff-native.jpg) |

`Present` continued to return `DXGI_STATUS_OCCLUDED`, including after bringing the viewer forward.
The first surface back-buffer file was black and was excluded. The foreground retry's copied
back-buffer was nonblack and visibly contained generated geometry; the final pairs above use that
verified capture path. This validates the native mesh/viewer path for these captures, but the
presentation status itself remains unresolved.

### Query, cave compile and full-view timings

| Measurement | Result | Scope |
|---|---:|---|
| Surface point queries W1 | 13.569 ms | 4,096 evaluator points, point evaluation only |
| Surface point queries W8 | 8.085 ms | same points, same field hash |
| Surface point queries W16 | 12.396 ms | same points, same field hash |
| Legacy owner density queries | 61.974 ms | same 4,096 points; reference timing, not a performance gate |
| Core world compile and query bridge | 36.295 ms; 45/45 exact | Surface recipe; `World::densityAt`, no render mesh |
| Existing cave-only shape compile | 0.100 s | no-manifest `type_3_Maze.json` smoke, from round 1 |
| Owner full-detail readiness | mean 2.882 s | 120 near tiles (64 LOD0 + 56 LOD1), 16 workers, four capture sites |
| Native Core full-detail readiness | mean 5.227 s | same tile count, workers and sites; range 4.401–6.636 s |

| Capture site | Owner | Native Core |
|---|---:|---:|
| Surface | 2.873 s | 4.401 s |
| Biome border | 2.904 s | 4.907 s |
| Coast | 2.877 s | 4.962 s |
| Cliff | 2.874 s | 6.636 s |

The cave compile and surface query figures are separate workloads. The surface viewer took longer:
the native 5.227 s mean is 81% above the owner's 2.882 s on these matched views. This 120-tile
clip-radius-1 workload is not the agreed 23.085 s matched-workload gate. All viewer runs used 16
workers; maximum observed full-detail time was 6.636 s at the upward-facing cliff camera.

### Round 2 run log

- The first evaluator build failed because the JSON parser version has no `IsBool`/`IsNull` methods.
  The parser was changed to inspect the JSON value variant, and the next isolated build passed.
- The first expanded interval audit failed with 102 escaped samples. The envelope fixes described
  above were applied and the final audit passed. No failing result was discarded from the report.
- The initial native D3D surface capture was black with an occluded presentation status. A
  foreground recapture still reported the same status but its back-buffer contained visible mesh
  geometry; only the verified foreground copy was used. All four final owner/native pairs are
  downscaled and below 18 KB per image.
- Successful final standalone builds completed in under one minute with `/MP16`, Normal priority
  and 16 CPUs. Existing `vswhere.exe` lookup output and C4838 narrowing warnings at
  `VoxelStrateManager.cpp:3974-3975` remain nonfatal. No process exceeded the 15-minute limit or
  8 GB cap; no `0xC0000142` retry occurred. The crash-folder check found only the pre-existing
  `UECC-Windows-F1A3EFD5469F5DD62E68EBBACAC84376_0000` from 2026-09-17 and no new UECC folder.
- No owner project or BuildHost project was built. No `.uasset` was opened or changed. No new source
  files were added.

### Remaining work by round

- **Round 2:** Evaluator-v2 surface recipe, matched 3D comparisons and expanded bounds audit are
  implemented. The measured residual mismatch, rendered-water gap, and owner/native cliff difference
  remain open for round 3 review; round 2 does not claim surface parity.
- **Round 3:** Add the finite-strate capsule route and support constraints, sweep it against the final
  composed field, and reject or repair any failing automatic plan. Verify full-evaluator W1/W8/W16
  hashes. Measure collision readiness separately from query and mesh readiness; demonstrate a
  headless/server field query without render meshes. Keep the route valid during all automatic
  changes, leave player edits unrestricted, and keep seasonal water fixed.
- **Round 4:** Wire the reviewed manifest into the season asset/content-hash path and connect Core
  behind `bUseVoxelForgeCore`; prove the flag-off legacy path is unchanged. Build only the isolated
  BuildHost target here. The owner builds and reviews the in-game surface and walkable route.
  Re-run the matched 23.085 s workload, report full-view and local query/collision readiness
  separately, and assess the ~1.57 s aim with valid captures.

### Run log

- First isolated full build compiled Core and passed the 199,209-line Core link-safety scan, then
  failed at viewer link: the new inline API symbols were not emitted and the standalone build lacked
  the GPU Far viewer implementation. No GPU Far source file exists in the standalone set.
- Retry adding the assumed `GpuFarViewer.cpp` failed at compile with `C1083` because that source file
  is absent. The build was changed to use local CPU-viewer link stubs under ignored
  `Standalone/Build/AssemblerM1/` output; Core remains GPU-free.
- The next full standalone build succeeded after moving the new API definitions out of line and
  isolating the GPU viewer stubs. Another full build succeeded after adding the height-map capture;
  a further build succeeded after adding manifest output; the final full rebuild after marking the
  manifest API for Core export also succeeded. The latest full build succeeded after changing the
  capture ramp to the observed shared height range. Each successful build took under one minute,
  used `/MP16`, Normal priority and all 16 allowed CPUs; sampled compiler processes remained well
  below 8 GB.
- Successful builds still print the environment's `'vswhere.exe' is not recognized` message and
  existing C4838 narrowing warnings in `VoxelStrateManager.cpp:3974-3975`. These did not stop the
  build. No `0xC0000142` retry occurred. A separate Git Bash `tail` inspection command failed with
  access denied while opening a file; it made no changes.
- No BuildHost or owner-project build was run this round. The checked
  `Saved/BuildHost/HostProject/Saved/Crashes/` folder contains one older `UECC-Windows-*` directory
  from 2026-09-17; there was no new crash folder from this round.

No Unreal route or asset was changed in this round, so there is no owner rebuild handoff yet.