proto: continuous swept road deck; coarse-LOD proxies keep thin pillars intact (L143)

Road: one swept-deck stamp on a shared cubic-Hermite centerline (stamp vocabulary V5), 376.8 m, max 8.5 deg, walk
audit clean, short-road control fails as expected. Pillars: regular fillPillar stamps get deterministic 24-sided
capped-cylinder proxies once the LOD step exceeds their radius or half-height (applies to all worlds). Owner hashes
unchanged (v227); five-fixture Clang/GCC determinism; fast tier green.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_016dhxM43dnWvUu2B5Ph1iG1

Standalone/Research/WorldAssemblerM3/Linux143/BuildL143Fixtures.py

@@ -0,0 +1,113 @@
+#!/usr/bin/env python3
+"""Build the L143 liminal pictures and walk-audit controls."""
+from __future__ import annotations
+
+import argparse
+import json
+import os
+from pathlib import Path
+
+
+ROOT = Path(__file__).resolve().parents[4]
+OWNER = Path(os.environ.get("VOXELFORGE_OWNER_DATA",
+                            ROOT / "Standalone/data/owner_world.json"))
+OUT_DEFAULT = Path(os.environ.get("VOXELFORGE_VERIFY_OUT", ROOT / "Saved/Linux/l143"))
+
+FLAT_FIELD = {
+    "version": 1,
+    "kind": "flatField",
+    "minimum_arena_clearance_m": 0.0,
+}
+
+
+def main() -> None:
+    parser = argparse.ArgumentParser(description=__doc__)
+    parser.add_argument("--out", type=Path, default=OUT_DEFAULT / "fixtures")
+    args = parser.parse_args()
+    args.out.mkdir(parents=True, exist_ok=True)
+    base = json.loads(OWNER.read_text(encoding="utf-8"))
+
+    monolith = dict(base)
+    monolith["surface_profile_override"] = dict(FLAT_FIELD)
+    monolith["motif_family_override"] = {
+        "version": 1,
+        "strate_index": 0,
+        "placement_policy": "seed,strate,stable_id",
+        "motifs": [{
+            "stable_id": "liminal/oversized-familiar-monolith-v1",
+            "kind": "cappedCylinder",
+            "radius_m": 1.6,
+            "height_m": 26.0,
+            "route_side_offset_m": 42.0,
+            "placement_radius_m": 0.0,
+            "fillet_radius_m": 0.6,
+            "blend_width_m": 1.2,
+            "minimum_spacing_m": 0.0,
+            "yaw_quarter_turns": 0,
+            "attachment": "seated_floor",
+        }],
+    }
+
+    hills = dict(base)
+    hills["surface_profile_override"] = {
+        "version": 1,
+        "kind": "periodicHills",
+        "amplitude_x_m": 2.2,
+        "amplitude_y_m": 2.2,
+        "wavelength_x_m": 80.0,
+        "wavelength_y_m": 80.0,
+        "minimum_arena_clearance_m": 0.0,
+    }
+
+    road_override = {
+        "stable_id": "liminal/road-clouds-v2",
+        "strate_index": 0,
+        "start_xy_m": [120.0, 340.0],
+        "path_length_m": 360.0,
+        "curve_control_offset_m": 84.0,
+        "deck_height_above_field_m": 44.0,
+        "rise_control_m": 22.0,
+        "half_width_m": 4.0,
+        "half_thickness_m": 1.0,
+        "sample_spacing_m": 1.0,
+        "support_spacing_m": 24.0,
+        "support_radius_m": 0.55,
+    }
+    road = dict(base)
+    road["surface_profile_override"] = dict(FLAT_FIELD)
+    road["liminal_road_override"] = dict(road_override)
+
+    short_control = dict(base)
+    short_control["surface_profile_override"] = dict(FLAT_FIELD)
+    short_override = dict(road_override)
+    short_override["path_length_m"] = 180.0
+    short_control["liminal_road_override"] = short_override
+
+    pillars = dict(base)
+    pillars["surface_profile_override"] = dict(FLAT_FIELD)
+    pillars["liminal_pillar_grid_override"] = {
+        "stable_id": "liminal/horizon-pillar-grid-v1",
+        "strate_index": 0,
+        "center_xy_m": [700.0, 800.0],
+        "rows": 15,
+        "columns": 15,
+        "spacing_m": 76.0,
+        "radius_m": 5.5,
+        "height_m": 40.0,
+    }
+
+    fixtures = (
+        ("flatField-monolith", monolith),
+        ("periodicHills", hills),
+        ("road-in-clouds", road),
+        ("road-short-control", short_control),
+        ("pillar-grid", pillars),
+    )
+    for name, fixture in fixtures:
+        path = args.out / f"liminal-{name}.json"
+        path.write_text(json.dumps(fixture, indent=2) + "\n", encoding="utf-8")
+        print(f"[L143Fixture] name={name} file={path} status=PASS")
+
+
+if __name__ == "__main__":
+    main()

Standalone/Research/WorldAssemblerM3/Linux143/CaptureL143.py

@@ -0,0 +1,463 @@
+#!/usr/bin/env python3
+"""Run L143 liminal determinism checks, walk audits and multi-LOD captures."""
+from __future__ import annotations
+
+import argparse
+import hashlib
+import json
+import math
+import os
+from pathlib import Path
+import re
+import shutil
+import subprocess
+import sys
+import time
+
+
+ROOT = Path(__file__).resolve().parents[4]
+OUT_DEFAULT = Path(os.environ.get("VOXELFORGE_VERIFY_OUT", ROOT / "Saved/Linux/l143"))
+CAPTURE_DEFAULT = Path(__file__).resolve().parent / "captures"
+LIMIT = ["taskset", "-c", "0-11", "prlimit", "--as=6442450944", "--"]
+Q_PER_METRE = 1024.0
+FOG_COLOR = "0.66,0.73,0.77"
+
+sys.path.insert(0, str(ROOT / "Standalone/Tools/verify"))
+from runner import bounded_run, current_stamp, first_stamp
+
+
+def fmt(values) -> str:
+    return ",".join(f"{value:.6f}" for value in values)
+
+
+def sha256(path: Path) -> str:
+    digest = hashlib.sha256()
+    with path.open("rb") as stream:
+        for block in iter(lambda: stream.read(1024 * 1024), b""):
+            digest.update(block)
+    return digest.hexdigest()
+
+
+def run_step(name: str, command: list[object], log: Path, *, env: dict[str, str],
+             stamped: bool = False, timeout_seconds: int = 1740,
+             expected_exit: int = 0) -> str:
+    expected_stamp = current_stamp() if stamped else None
+    if stamped:
+        binary = Path(str(command[0]))
+        probe = bounded_run([str(binary), "--print-source-stamp"], timeout=15)
+        if probe is None or probe.returncode != 0 or first_stamp(probe.stdout or "") != expected_stamp:
+            raise RuntimeError(f"{name} refused a stale executable: {binary}")
+    started = time.monotonic()
+    log.parent.mkdir(parents=True, exist_ok=True)
+    with log.open("w", encoding="utf-8") as stream:
+        result = subprocess.run([*LIMIT, f"timeout", f"{timeout_seconds}s",
+                                 *map(str, command)], cwd=ROOT, env=env,
+                                stdout=stream, stderr=subprocess.STDOUT,
+                                timeout=timeout_seconds + 5, check=False)
+    elapsed = time.monotonic() - started
+    output = log.read_text(encoding="utf-8", errors="replace")
+    print(f"[L143Run] step={name} elapsed_s={elapsed:.3f} exit={result.returncode} log={log}",
+          flush=True)
+    if stamped and (first_stamp(output) != expected_stamp or current_stamp() != expected_stamp):
+        raise RuntimeError(f"{name} source stamp mismatch; see {log}")
+    if result.returncode != expected_exit:
+        raise RuntimeError(f"{name} exit={result.returncode}, expected={expected_exit}; see {log}")
+    return output
+
+
+def route_frame(manifest_path: Path) -> tuple[tuple[float, float, float],
+                                               tuple[float, float, float]]:
+    manifest = json.loads(manifest_path.read_text(encoding="utf-8"))
+    strata = [entry for entry in manifest["plan"]["strates"]
+              if entry.get("route") and len(entry["route"]) >= 2]
+    if not strata:
+        raise RuntimeError(f"no planned SurfaceWorld route in {manifest_path}")
+    route = strata[0]["route"]
+    points = [tuple(float(value) / Q_PER_METRE for value in item["position_q"])
+              for item in route]
+    lengths = [math.dist(a, b) for a, b in zip(points, points[1:])]
+    total = sum(lengths)
+    if total <= 1.0e-6:
+        raise RuntimeError(f"degenerate planned route in {manifest_path}")
+
+    def at(distance: float) -> tuple[float, float, float]:
+        remaining = max(0.0, min(total, distance))
+        for index, (a, b, length) in enumerate(zip(points, points[1:], lengths)):
+            if remaining <= length or index == len(lengths) - 1:
+                if length <= 1.0e-9:
+                    return b
+                t = remaining / length
+                return tuple(a[axis] + (b[axis] - a[axis]) * t for axis in range(3))
+            remaining -= length
+        return points[-1]
+
+    center = at(total * 0.5)
+    before, after = at(total * 0.5 - 1.0), at(total * 0.5 + 1.0)
+    dx, dy = after[0] - before[0], after[1] - before[1]
+    length = math.hypot(dx, dy)
+    if length <= 1.0e-9:
+        raise RuntimeError(f"degenerate route tangent in {manifest_path}")
+    return center, (dx / length, dy / length, 0.0)
+
+
+def camera_angles(camera, target) -> tuple[float, float]:
+    dx, dy, dz = (target[index] - camera[index] for index in range(3))
+    return math.degrees(math.atan2(dx, dy)), math.degrees(math.atan2(dz, math.hypot(dx, dy)))
+
+
+def point_toward(camera, target) -> tuple[float, ...]:
+    yaw, pitch = camera_angles(camera, target)
+    return (*camera, yaw, pitch)
+
+
+def stamp(layout: dict, stable_id: str) -> dict:
+    for record in layout.get("stamps", []):
+        if record.get("stable_id") == stable_id:
+            return record
+    raise RuntimeError(f"missing resolved stamp {stable_id}")
+
+
+def make_views(name: str, manifest_path: Path, layout_path: Path):
+    manifest = json.loads(manifest_path.read_text(encoding="utf-8"))
+    layout = json.loads(layout_path.read_text(encoding="utf-8"))
+    center, tangent = route_frame(manifest_path)
+    tx, ty, _ = tangent
+    nx, ny = -ty, tx
+    base_height = manifest["recipe"]["surface_profile"]["h0_q"] / Q_PER_METRE
+    if name == "flatField-monolith":
+        monolith = stamp(layout, "liminal/oversized-familiar-monolith-v1")
+        sx, sy, _ = (value / 1.0e6 for value in monolith["position_um"])
+        floor = monolith["floor_um"] / 1.0e6
+        eye_camera = (sx - tx * 36.0, sy - ty * 36.0, floor + 1.6)
+        eye_target = (sx, sy, floor + 10.5)
+        wide_camera = (sx - tx * 42.0 - nx * 18.0,
+                       sy - ty * 42.0 - ny * 18.0, floor + 42.0)
+        wide_target = (sx, sy, floor + 8.0)
+        return {
+            "eye": (eye_camera, eye_target, 20),
+            "wide": (wide_camera, wide_target, 24),
+            "height_center": floor,
+            "height_range": 38.0,
+        }
+    if name == "periodicHills":
+        # Route points are capsule centers: +0.72 m places the view at 1.60 m above ground.
+        eye_camera = (center[0], center[1], center[2] + 0.72)
+        eye_target = (center[0] - tx * 360.0, center[1] - ty * 360.0,
+                      center[2] + 0.72)
+        wide_camera = (center[0] - tx * 36.0 - nx * 28.0,
+                       center[1] - ty * 36.0 - ny * 28.0, center[2] + 30.0)
+        wide_target = (center[0] - tx * 310.0, center[1] - ty * 310.0,
+                       center[2] + 0.72)
+        return {
+            "eye": (eye_camera, eye_target, 20),
+            "wide": (wide_camera, wide_target, 28),
+            "height_center": base_height,
+            "height_range": 6.0,
+        }
+    if name == "road-in-clouds":
+        deck = stamp(layout,"liminal/road-clouds-v2/deck/000")
+        path_um = deck.get("sweep_path_um", [])
+        if len(path_um) < 2:
+            raise RuntimeError("road layout has no resolved continuous swept path")
+        points = [tuple(value / 1.0e6 for value in point) for point in path_um]
+        half_thickness = deck["half_extents_um"][2] / 1.0e6
+        top = lambda point: point[2] + half_thickness
+        index = max(1, len(points) // 12)
+        camera_dx = points[index + 1][0] - points[index - 1][0]
+        camera_dy = points[index + 1][1] - points[index - 1][1]
+        camera_tangent_length = math.hypot(camera_dx, camera_dy)
+        camera_tx, camera_ty = (camera_dx / camera_tangent_length,
+                                 camera_dy / camera_tangent_length)
+        camera_nx, camera_ny = -camera_ty, camera_tx
+        half_width = deck["half_extents_um"][1] / 1.0e6
+        eye_target_index = min(len(points) - 1, index + 25)
+        eye_camera = (points[index][0] + camera_nx * (half_width + 2.0),
+                      points[index][1] + camera_ny * (half_width + 2.0),
+                      top(points[index]) + 1.6)
+        eye_target = (points[eye_target_index][0] + camera_nx * (half_width - 0.4),
+                      points[eye_target_index][1] + camera_ny * (half_width - 0.4),
+                      top(points[eye_target_index]) + 0.3)
+        middle = len(points) // 2
+        dx = points[middle + 1][0] - points[middle - 1][0]
+        dy = points[middle + 1][1] - points[middle - 1][1]
+        tangent_length = math.hypot(dx, dy)
+        tx, ty = dx / tangent_length, dy / tangent_length
+        nx, ny = -ty, tx
+        wide_target_index = min(len(points) - 1, middle + 30)
+        wide_camera = (points[middle][0] - tx * 35.0 + nx * 30.0,
+                       points[middle][1] - ty * 35.0 + ny * 30.0,
+                       top(points[middle]) + 25.0)
+        wide_target = (points[wide_target_index][0], points[wide_target_index][1],
+                       top(points[wide_target_index]) - 5.0)
+        cloud_camera = (points[middle][0] - tx * 18.0 + nx * 12.0,
+                        points[middle][1] - ty * 18.0 + ny * 12.0,
+                        base_height + 1.6)
+        cloud_target = (points[middle][0] + tx * 8.0,
+                        points[middle][1] + ty * 8.0,
+                        points[middle][2] - half_thickness * 0.35)
+        return {
+            "eye": (eye_camera, eye_target, 3),
+            "wide": (wide_camera, wide_target, 3),
+            "cloud-up": (cloud_camera, cloud_target, 3),
+            "height_center": base_height + 23.0,
+            "height_range": 60.0,
+            "road_deck": top(points[middle]),
+            "road_width": 2.0 * half_width,
+        }
+    if name == "pillar-grid":
+        pillars = [row for row in layout.get("stamps", [])
+            if row.get("stable_id", "").startswith("liminal/horizon-pillar-grid-v1/pillar/")]
+        if len(pillars) < 9:
+            raise RuntimeError("pillar-grid layout has too few resolved supports")
+        xs = [row["position_um"][0] / 1.0e6 for row in pillars]
+        ys = [row["position_um"][1] / 1.0e6 for row in pillars]
+        floor = min((row["position_um"][2] - row["half_extents_um"][2]) / 1.0e6
+                    for row in pillars)
+        cx, cy = (min(xs) + max(xs)) * 0.5, (min(ys) + max(ys)) * 0.5
+        eye_camera = (min(xs) - 78.0, cy, floor + 1.6)
+        eye_target = (max(xs) + 90.0, cy, floor + 1.6)
+        wide_camera = (cx - 280.0, cy - 420.0, floor + 230.0)
+        wide_target = (cx, cy, floor + 6.0)
+        return {
+            "eye": (eye_camera, eye_target, 3),
+            "wide": (wide_camera, wide_target, 3),
+            "height_center": floor + 12.0,
+            "height_range": 42.0,
+        }
+    raise RuntimeError(f"no capture framing for fixture {name}")
+
+
+def headless_command(binary: Path, fixture: Path, camera, mesh: Path,
+                     manifest: Path, layout: Path, workers: int,
+                     clip_radius: int, *, hash_tiles: bool = False,
+                     audit_road: bool = False, max_level: int = 0,
+                     far_lods: bool = False,
+                     max_clip_override: int | None = None) -> list[object]:
+    max_clip_level = (max_clip_override if max_clip_override is not None else
+                      8 if far_lods else max_level)
+    command: list[object] = [binary, fixture, f"--workers={workers}",
+        "--seed=0", "--world-assembler-prototype", "--stream-benchmark", "--stream-pipeline",
+        "--force-generate", f"--clip-radius={clip_radius}",
+        f"--max-clip-level={max_clip_level}",
+        f"--max-level={max_level}", "--render-distance-chunks=0",
+        f"--camera={fmt(point_toward(camera, (camera[0], camera[1] + 1.0, camera[2])))}",
+        f"--mesh-export={mesh}", f"--world-assembler-manifest-output={manifest}",
+        f"--resolved-layout-output={layout}"]
+    if hash_tiles:
+        command.append("--stream-hash-tiles")
+    if audit_road:
+        command.append("--audit-liminal-road-walk")
+    return command
+
+
+def determinism_digest(output: str, manifest_path: Path,
+                       layout_path: Path) -> tuple[str, str, str]:
+    tile_hashes = sorted(line for line in output.splitlines()
+                         if line.startswith("[PipelineTileHash] "))
+    if not manifest_path.is_file() or not layout_path.is_file() or not tile_hashes:
+        raise RuntimeError("determinism run omitted manifest, layout or per-tile hashes")
+    manifest = json.loads(manifest_path.read_text(encoding="utf-8"))
+    layout = json.loads(layout_path.read_text(encoding="utf-8"))
+    manifest_digest = (manifest["content_hash"],manifest["recipe"]["content_hash"],
+                       manifest["plan"]["content_hash"])
+    return ("|".join(manifest_digest),layout["stable_identity"],"\n".join(tile_hashes))
+
+
+def run_determinism(name: str, fixture: Path, view, *, binaries: dict[str, Path],
+                    out: Path, env: dict[str, str], max_level: int = 0,
+                    far_lods: bool = False, max_clip_override: int | None = None) -> None:
+    camera, _, _ = view["eye"]
+    clip_radius = 1
+    max_clip = 0
+    baseline = None
+    cells = 0
+    for compiler, workers in ((compiler, workers)
+                              for compiler in ("clang", "gcc")
+                              for workers in (1, 8, 12)):
+        tag = f"{name}-{compiler}-w{workers}"
+        run_dir = out / "determinism" / tag
+        run_dir.mkdir(parents=True, exist_ok=True)
+        mesh = run_dir / "feature.vfmesh"
+        manifest = run_dir / "manifest.json"
+        layout = run_dir / "layout.json"
+        command = headless_command(binaries[compiler], fixture,camera,mesh,manifest,
+            layout,workers,max_clip,hash_tiles=True,max_level=max_level,
+            far_lods=far_lods,max_clip_override=max_clip_override)
+        output = run_step(tag,command,out/"logs"/f"determinism-{tag}.log",
+                          env=env,stamped=True)
+        digest = determinism_digest(output,manifest,layout)
+        if baseline is None:
+            baseline = digest
+        elif digest != baseline:
+            raise RuntimeError(f"{name} diverged at {compiler} W{workers}; see determinism logs")
+        cells += 1
+    print(f"[L143Determinism] fixture={name} compiler_worker_cells={cells} identical=yes status=PASS",
+          flush=True)
+
+
+def export_and_capture(name: str, fixture: Path, views: dict, *,
+                       headless: Path, renderer: Path, out: Path,
+                       artifact_dir: Path, env: dict[str, str]) -> None:
+    view_names = ("eye", "wide", "cloud-up") if name == "road-in-clouds" else ("eye", "wide")
+    for view_name in view_names:
+        camera, target, clip_radius = views[view_name]
+        clip_radius = min(clip_radius,3)
+        stem = f"{name}-{view_name}"
+        mesh = out / "capture-meshes" / f"{stem}.vfmesh"
+        manifest = out / "capture-manifests" / f"{stem}.json"
+        layout = out / "capture-layouts" / f"{stem}.json"
+        png = out / "capture-png" / f"{stem}.png"
+        image = artifact_dir / f"{stem}.jpg"
+        for path in (mesh,manifest,layout,png,image):
+            path.parent.mkdir(parents=True,exist_ok=True)
+        command = headless_command(headless,fixture,camera,mesh,manifest,layout,12,
+            clip_radius,max_level=-1,far_lods=True,
+            max_clip_override=2 if name == "road-in-clouds" else None)
+        output = run_step(f"capture-{stem}-export",command,
+            out/"logs"/f"capture-{stem}-export.log",env=env,stamped=True)
+        if not mesh.is_file() or mesh.stat().st_size == 0:
+            raise RuntimeError(f"{stem} produced an empty mesh")
+        yaw, pitch = camera_angles(camera,target)
+        height_center = views["height_center"]
+        height_range = views["height_range"]
+        if name == "road-in-clouds":
+            fog_start,fog_end,fog_color=(24,260,"0.88,0.93,0.95")
+        elif name == "pillar-grid":
+            fog_start,fog_end,fog_color=220,1250,"0.82,0.88,0.91"
+        elif name == "periodicHills":
+            fog_start,fog_end,fog_color=210,1000,"0.78,0.84,0.88"
+        else:
+            fog_start,fog_end,fog_color=30,105,FOG_COLOR
+        renderer_command = [renderer,mesh,png,"--size=1600x900","--fov-deg=72",
+            f"--camera-m={fmt(camera)}",f"--yaw-deg={yaw:.6f}",
+            f"--pitch-deg={pitch:.6f}","--tile-skirts=on","--shade=readable",
+            "--headlamp=off","--height-tint=on",f"--height-center-m={height_center:.6f}",
+            f"--height-range-m={height_range:.6f}","--light-direction=-0.42,-0.58,0.70",
+            "--fog=on",f"--fog-start-m={fog_start}",f"--fog-end-m={fog_end}",
+            f"--fog-color={fog_color}"]
+        run_step(f"capture-{stem}-render",renderer_command,
+            out/"logs"/f"capture-{stem}-render.log",env=env,stamped=True)
+        run_step(f"capture-{stem}-jpeg",["ffmpeg","-nostdin","-hide_banner","-loglevel",
+            "error","-y","-i",png,"-frames:v","1","-q:v","4",image],
+            out/"logs"/f"capture-{stem}-jpeg.log",env=env)
+        quality = run_step(f"capture-{stem}-quality",
+            [sys.executable,ROOT/"Standalone/Tools/verify/capture_quality.py",image],
+            out/"logs"/f"capture-{stem}-quality.log",env=env)
+        if "[CaptureQuality]" not in quality or not image.is_file() \
+                or image.stat().st_size > 300_000:
+            raise RuntimeError(f"{stem} capture failed quality or size checks")
+        eye_height = "1.600m" if view_name in ("eye", "cloud-up") else "wide"
+        print(f"[L143Capture] fixture={name} view={view_name} eye_height={eye_height} "
+              f"camera_m=({fmt(camera)}) target_m=({fmt(target)}) bytes={image.stat().st_size} "
+              f"sha256={sha256(image)} status=PASS",flush=True)
+
+
+def run_road_walk_audit(fixture: Path, view, *, headless: Path,
+                        out: Path, env: dict[str, str]) -> None:
+    camera = view["eye"][0]
+    run_dir = out / "road-walk-audit"
+    run_dir.mkdir(parents=True,exist_ok=True)
+    output = run_step("road-walk-audit",headless_command(headless,fixture,camera,
+        run_dir/"audit.vfmesh",run_dir/"manifest.json",run_dir/"layout.json",12,1,
+        audit_road=True),out/"logs"/"road-walk-audit.log",env=env,stamped=True)
+    if not re.search(r"\[LiminalRoadWalkAudit\].*status=PASS",output):
+        raise RuntimeError("raised road failed the Core capsule walk audit")
+
+
+def run_road_short_negative_control(fixture: Path, view, *, headless: Path,
+                                    out: Path, env: dict[str, str]) -> None:
+    camera = view["eye"][0]
+    run_dir = out / "road-short-negative-control"
+    run_dir.mkdir(parents=True,exist_ok=True)
+    output = run_step("road-short-negative-control",
+        headless_command(headless,fixture,camera,run_dir/"control.vfmesh",
+            run_dir/"manifest.json",run_dir/"layout.json",12,1,audit_road=True),
+        out/"logs"/"road-short-negative-control.log",env=env,stamped=True,
+        expected_exit=14)
+    match = re.search(r"\[LiminalRoadWalkAudit\].*path_length_m=([0-9.]+).*status=FAIL",output)
+    if not match or float(match.group(1)) >= 300.0:
+        raise RuntimeError("short-road negative control did not falsify the length gate")
+    print(f"[L143RoadNegativeControl] path_length_m={match.group(1)} "
+          "expected=FAIL status=PASS",flush=True)
+
+
+def retain_unchanged_captures(artifact_dir: Path) -> None:
+    reference_dir = Path(__file__).resolve().parents[1] / "Linux142" / "captures"
+    for name in ("flatField-monolith", "periodicHills"):
+        for view in ("eye", "wide"):
+            filename = f"{name}-{view}.jpg"
+            source, destination = reference_dir / filename, artifact_dir / filename
+            if not source.is_file():
+                raise RuntimeError(f"missing L142 reference capture {source}")
+            shutil.copy2(source,destination)
+            if sha256(source) != sha256(destination):
+                raise RuntimeError(f"unchanged reference capture copy differs: {filename}")
+            print(f"[L143Capture] fixture={name} view={view} retained_from=Linux142 "
+                  f"sha256={sha256(destination)} status=PASS",flush=True)
+
+
+def main() -> int:
+    parser = argparse.ArgumentParser(description=__doc__)
+    parser.add_argument("--out", type=Path, default=OUT_DEFAULT)
+    parser.add_argument("--artifact-dir", type=Path, default=CAPTURE_DEFAULT)
+    parser.add_argument("--headless-clang", type=Path, required=True)
+    parser.add_argument("--headless-gcc", type=Path, required=True)
+    parser.add_argument("--renderer", type=Path, required=True)
+    args = parser.parse_args()
+
+    out = args.out.resolve()
+    artifact_dir = args.artifact_dir.resolve()
+    fixture_dir = out / "fixtures"
+    for directory in (out,fixture_dir,artifact_dir):
+        directory.mkdir(parents=True,exist_ok=True)
+    env = os.environ.copy()
+    env["VOXELFORGE_VERIFY_OUT"] = str(out)
+    env["VOXELFORGE_OWNER_DATA"] = str(ROOT/"Standalone/data/owner_world.json")
+    env["LP_NUM_THREADS"] = "12"
+    env["XDG_CACHE_HOME"] = str(out/"xdg-cache")
+    run_step("build-fixtures",[sys.executable,
+        ROOT/"Standalone/Research/WorldAssemblerM3/Linux143/BuildL143Fixtures.py",
+        f"--out={fixture_dir}"],out/"logs"/"build-fixtures.log",env=env)
+
+    binaries = {"clang":args.headless_clang.resolve(),"gcc":args.headless_gcc.resolve()}
+    fixtures = {
+        "flatField-monolith":fixture_dir/"liminal-flatField-monolith.json",
+        "periodicHills":fixture_dir/"liminal-periodicHills.json",
+        "road-in-clouds":fixture_dir/"liminal-road-in-clouds.json",
+        "pillar-grid":fixture_dir/"liminal-pillar-grid.json",
+    }
+    probed = {}
+    for name,fixture in fixtures.items():
+        probe_dir=out/"plan-probes"/name
+        probe_dir.mkdir(parents=True,exist_ok=True)
+        camera=(0.0,0.0,-500.0)
+        output=run_step(f"plan-probe-{name}",headless_command(binaries["clang"],fixture,
+            camera,probe_dir/"probe.vfmesh",probe_dir/"manifest.json",
+            probe_dir/"layout.json",12,1),out/"logs"/f"plan-probe-{name}.log",
+            env=env,stamped=True)
+        if "[WorldAssemblerFullManifest]" not in output:
+            raise RuntimeError(f"{name} probe omitted its full plan manifest")
+        probed[name]=make_views(name,probe_dir/"manifest.json",probe_dir/"layout.json")
+
+    for name,fixture in fixtures.items():
+        run_determinism(name,fixture,probed[name],binaries=binaries,out=out,env=env)
+    run_determinism("pillar-grid-far-lod",fixtures["pillar-grid"],probed["pillar-grid"],
+        binaries=binaries,out=out,env=env,max_level=-1,far_lods=True,max_clip_override=8)
+    run_road_walk_audit(fixtures["road-in-clouds"],probed["road-in-clouds"],
+        headless=binaries["clang"],out=out,env=env)
+    run_road_short_negative_control(fixture_dir/"liminal-road-short-control.json",
+        probed["road-in-clouds"],headless=binaries["clang"],out=out,env=env)
+    retain_unchanged_captures(artifact_dir)
+    for name in ("road-in-clouds", "pillar-grid"):
+        fixture=fixtures[name]
+        export_and_capture(name,fixture,probed[name],headless=binaries["clang"],
+            renderer=args.renderer.resolve(),out=out,artifact_dir=artifact_dir,env=env)
+    return 0
+
+
+if __name__ == "__main__":
+    try:
+        raise SystemExit(main())
+    except Exception as error:
+        print(f"[L143Capture] status=FAIL error={error}",file=sys.stderr,flush=True)
+        raise SystemExit(1)

Standalone/Research/WorldAssemblerM3/Linux143/REPORT.md

@@ -0,0 +1,64 @@
+# L143 — liminal polish
+
+## Captures
+
+### Road
+
+Eye-height:
+
+![Road deck at eye height](captures/road-in-clouds-eye.jpg)
+
+Wide:
+
+![Road deck and supports, wide view](captures/road-in-clouds-wide.jpg)
+
+Looking up from the cloud floor:
+
+![Road deck underside from the cloud floor](captures/road-in-clouds-cloud-up.jpg)
+
+### Pillar grid
+
+Eye-height:
+
+![Pillar grid at eye height](captures/pillar-grid-eye.jpg)
+
+Wide:
+
+![Pillar grid, wide view](captures/pillar-grid-wide.jpg)
+
+### Kept from L142
+
+These four captures are byte-identical to L142.
+
+![Monolith, eye view](captures/flatField-monolith-eye.jpg)
+
+![Monolith, wide view](captures/flatField-monolith-wide.jpg)
+
+![Periodic hills, eye view](captures/periodicHills-eye.jpg)
+
+![Periodic hills, wide view](captures/periodicHills-wide.jpg)
+
+## Result
+
+The road is one continuous swept deck, and the distant pillar silhouettes remain complete and consistent. The monolith and periodic hills were retained unchanged.
+
+## Changes and causes
+
+- The road edge broke where independently capped deck segments overlapped. The road now resolves to one swept-deck stamp with a shared cubic-Hermite centerline and continuous cross-section; the centerline is sampled at 1 m spacing (361 points). The 8 m deck is 376.829 m long and retains 17 support posts. The sweep path is serialized in stamp-vocabulary V5.
+- Pillars disappeared or narrowed when the coarse marching-cubes lattice skipped their cross-section. The pillar stamp's interval proof is unsupported, so it conservatively kept tiles but did not protect the mesh from undersampling. At LOD4 the sample spacing is 32 voxels (8 m), already greater than the 5.5 m pillar radius; spacing rises to 64 and 128 voxels at LOD5 and LOD6. The shared meshing path now emits deterministic 24-sided capped-cylinder proxies for regular `fillPillar` stamps once the sample step exceeds their radius or half-height. The same rule applies outside the liminal fixture. The radial approximation error for this fixture is about 4.7 cm, below one 25 cm voxel.
+
+## Measurements
+
+- Road walk audit covered the full 376.829 m route at 1,081 surface stations, with 68,103 capsule samples and 7,096 support samples: 0 blocked, 0 unsupported, 0 grade failures, and 0 surface misses. Measured maximum grade was 8.512° against a 15° limit; deck width was 8 m against a 3 m minimum. `road-short-negative-control` failed the walk audit as expected at 210.351 m.
+- Determinism covered five fixtures—monolith, periodic hills, road, pillar grid, and far-LOD pillar grid—across Clang/GCC and W1/W8/W12 (six compiler/worker cells per fixture). All five reported identical outputs.
+- Clang and GCC builds passed on source stamp `1baa3a711f7f96df2e70fc93579f41ad0b0211eb42fcb51dabf522e33d888877`. The capture runner and capture-quality checks passed for all requested views.
+- Fast tier passed in 292.3 s. Its pinned L130-v227 reach-unit owner hashes match exactly: 12/12 rows for each owner fixture, with W1 and W12 identical. Historical L46/L53 hash comparisons remain diagnostic-only and are not the current owner-hash gate.
+
+## Checks and limits
+
+- Passed: road audit and short-road negative control; five-fixture Clang/GCC determinism; Clang and GCC builds; capture quality; fast tier; `git diff --check`.
+- Not run: Unreal build (no Unreal `Source/` files changed) and L80 performance timing (this round made no performance claim).
+- The coarse proxy is limited to regular `fillPillar` stamps; irregular pillars and other stamp kinds continue through their existing SDF path. The proxy was exercised at LOD4–6 in the pillar-grid captures.
+- Unreal `Source/` files changed: none. Changed standalone source files: `Standalone/Core/include/VoxelForgeCore/VoxelForgeCore.h`, `Standalone/Core/src/ResolvedLayoutInternal.h`, `Standalone/Core/src/ShapeWorldInternal.h`, `Standalone/Core/src/VoxelForgeCore.cpp`, `Standalone/Source/StreamBenchmarkHeadless.cpp`, `Standalone/Source/StreamBenchmarkPipeline.h`, and `Standalone/Source/WorldAssemblyPrototype.h`.
+
+Detailed logs are in `Saved/Linux/l143/`; the capture and audit transcript is `Saved/Linux/l143/logs/capture-runner.log`, the walk audit is `Saved/Linux/l143/logs/road-walk-audit.log`, and the fast-tier summary is `Saved/Linux/l143/fast-summary.json`.