feat(core): profiled heightfields, slice 1: periodicHills, mirroredRelief, flatField (L53); research R22

WorldAssemblySurfaceProfileV1 on the native SurfaceWorld recipe and plan; version 0 'natural' is omitted
from serialized identity, so the owner world is unchanged. periodicHills (seeded cosine hills, plan-time
grade <= 15 deg), mirroredRelief (cap mirrors the floor by lambda, clearance checked) and flatField share
one profile function for points, lattice classification and exact cosine-extrema intervals (0 interval
misses in brute-force audits). Style-override fixtures with planned passages. Cold whole view about 1.33 s
for each profile vs 1.74 s natural SW (Clang). Owner hashes identical to L52; fast/medium/full PASS.
Research R22: SurfaceWorld critical path to about 1 s.

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

Standalone/Research/WorldAssemblerM3/Linux53/CaptureHeightfieldProfilesL53.py

@@ -0,0 +1,182 @@
+#!/usr/bin/env python3
+"""Capture eye-height and overview views for the three L53 heightfield profiles."""
+from __future__ import annotations
+
+import argparse
+import json
+import math
+import os
+from pathlib import Path
+import subprocess
+import sys
+import time
+
+
+ROOT = Path(__file__).resolve().parents[4]
+OUT_DEFAULT = Path(os.environ.get("VOXELFORGE_VERIFY_OUT", ROOT / "Saved/Linux/l53"))
+LIMIT = ["taskset", "-c", "0-11", "prlimit", "--as=6442450944", "--"]
+PROFILES = ("periodicHills", "mirroredRelief", "flatField")
+Q_PER_METRE = 1024.0
+
+sys.path.insert(0, str(ROOT / "Standalone/Tools/verify"))
+from runner import bounded_run, current_stamp, first_stamp
+
+
+def fmt(values: tuple[float, ...]) -> str:
+    return ",".join(f"{value:.6f}" for value in values)
+
+
+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"))
+    # Core profile coordinates are 1/256 of a Core voxel. In this world that is 1024 q/m.
+    scale = 1.0 / Q_PER_METRE
+    candidates = [entry for entry in manifest["plan"]["strates"]
+                  if entry.get("route") and len(entry["route"]) >= 2]
+    if not candidates:
+        raise RuntimeError(f"no planned route points in {manifest_path}")
+    route = candidates[0]["route"]
+    points = [tuple(float(value) * scale 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]:
+        left = max(0.0, min(total, distance))
+        for a, b, length in zip(points, points[1:], lengths):
+            if left <= length or (a, b) == (points[-2], points[-1]):
+                if length <= 1.0e-9:
+                    return b
+                t = left / length
+                return tuple(a[axis] + (b[axis] - a[axis]) * t for axis in range(3))
+            left -= 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"route tangent is degenerate in {manifest_path}")
+    return center, (dx / length, dy / length, 0.0)
+
+
+def run_step(name: str, command: list[str], log: Path, *, env: dict[str, str],
+             stamped: bool = False) -> None:
+    expected = current_stamp() if stamped else None
+    if stamped:
+        binary = Path(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:
+            raise RuntimeError(f"{name} refused an unstamped or stale executable: {binary}")
+    started = time.monotonic()
+    with log.open("w", encoding="utf-8") as stream:
+        result = subprocess.run([*LIMIT, "timeout", "1740s", *map(str, command)],
+            cwd=ROOT, env=env, stdout=stream, stderr=subprocess.STDOUT,
+            timeout=1745, check=False)
+    elapsed = time.monotonic() - started
+    print(f"[L53CaptureRun] step={name} elapsed={elapsed:.1f}s exit={result.returncode} log={log}",
+          flush=True)
+    output = log.read_text(encoding="utf-8", errors="replace")
+    if stamped and (first_stamp(output) != expected or current_stamp() != expected):
+        raise RuntimeError(f"{name} source stamp mismatch; see {log}")
+    if name.endswith("-quality"):
+        for line in output.splitlines():
+            if line.startswith("[CaptureQuality]"):
+                print(line, flush=True)
+    if result.returncode != 0:
+        raise RuntimeError(f"{name} failed; see {log}")
+
+
+def camera_angles(camera: tuple[float, float, float],
+                  target: tuple[float, float, float]) -> 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 main() -> int:
+    parser = argparse.ArgumentParser(description=__doc__)
+    parser.add_argument("--out", type=Path, default=OUT_DEFAULT)
+    parser.add_argument("--fixture-dir", type=Path)
+    parser.add_argument("--artifact-dir", type=Path,
+                        default=ROOT / "Standalone/Research/WorldAssemblerM3/Linux53/captures")
+    parser.add_argument("--headless", type=Path, required=True)
+    parser.add_argument("--renderer", type=Path, required=True)
+    args = parser.parse_args()
+    out = args.out.resolve()
+    fixture_dir = (args.fixture_dir or out / "fixtures").resolve()
+    artifact_dir = args.artifact_dir.resolve()
+    png_dir = out / "capture-png"
+    mesh_dir = out / "profile-meshes"
+    for directory in (out, png_dir, mesh_dir, artifact_dir):
+        directory.mkdir(parents=True, exist_ok=True)
+    env = os.environ.copy()
+    env["LP_NUM_THREADS"] = "12"
+    env["XDG_CACHE_HOME"] = str(out / "xdg-cache")
+
+    for profile in PROFILES:
+        fixture = fixture_dir / f"style-override-profile-{profile}.json"
+        manifest = fixture_dir / f"style-override-profile-{profile}-manifest.json"
+        if not fixture.is_file() or not manifest.is_file():
+            raise RuntimeError(f"missing profile fixture or manifest for {profile}")
+        center, tangent = route_frame(manifest)
+        cx, cy, cz = center
+        tx, ty, _ = tangent
+        eye = (cx, cy, cz + 0.72)
+        eye_target = (cx + tx * 15.0, cy + ty * 15.0, cz + 0.72)
+        overview_camera = (cx - tx * 48.0 - ty * 25.0,
+                           cy - ty * 48.0 + tx * 25.0, cz + 43.0)
+        overview_target = (cx + tx * 22.0, cy + ty * 22.0, cz + 0.4)
+
+        for view, camera, target, clip_radius in (
+            ("eye", eye, eye_target, 3),
+            ("overview", overview_camera, overview_target, 6),
+        ):
+            stem = f"{profile}-{view}"
+            mesh = mesh_dir / f"{stem}.vfmesh"
+            png = png_dir / f"{stem}.png"
+            image = artifact_dir / f"{stem}.jpg"
+            yaw, pitch = camera_angles(camera, target)
+            camera_spec = (*camera, yaw, pitch)
+            headless_command = [args.headless, fixture, "--workers=12",
+                "--world-assembler-prototype", "--stream-benchmark", "--stream-pipeline",
+                "--force-generate", f"--clip-radius={clip_radius}",
+                "--max-clip-level=0", "--max-level=0", "--render-distance-chunks=0",
+                "--recipe=surface-world", f"--camera={fmt(camera_spec)}",
+                f"--mesh-export={mesh}",
+                f"--world-assembler-manifest-output={manifest}"]
+            run_step(f"{stem}-export", headless_command,
+                out / f"capture-{stem}-export.log", env=env, stamped=True)
+            if not mesh.is_file() or mesh.stat().st_size == 0:
+                raise RuntimeError(f"headless export produced no mesh for {stem}")
+            focus = (*target, 54.0 if view == "overview" else 26.0)
+            renderer_command = [args.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=off", "--shade=readable",
+                "--headlamp=on", "--height-tint=on", f"--height-center-m={cz:.6f}",
+                "--height-range-m=10", "--tile-edges=off", f"--focus-region={fmt(focus)}"]
+            run_step(f"{stem}-render", renderer_command,
+                out / f"capture-{stem}-render.log", env=env, stamped=True)
+            run_step(f"{stem}-jpeg", ["ffmpeg", "-nostdin", "-hide_banner",
+                "-loglevel", "error", "-y", "-i", png, "-frames:v", "1", "-q:v", "4", image],
+                out / f"capture-{stem}-jpeg.log", env=env)
+            quality = ROOT / "Standalone/Tools/verify/capture_quality.py"
+            run_step(f"{stem}-quality", [sys.executable, quality, image],
+                out / f"capture-{stem}-quality.log", env=env)
+            if not image.is_file() or not 0 < image.stat().st_size <= 300_000:
+                raise RuntimeError(f"capture size is invalid for {stem}")
+            print(f"[L53HeightfieldCapture] profile={profile} view={view} file={image} "
+                  f"camera_m=({fmt(camera)}) target_m=({fmt(target)}) "
+                  f"bytes={image.stat().st_size} status=PASS", flush=True)
+
+    return 0
+
+
+if __name__ == "__main__":
+    try:
+        raise SystemExit(main())
+    except Exception as error:
+        print(f"[L53HeightfieldCapture] status=FAIL error={error}", file=sys.stderr, flush=True)
+        raise SystemExit(1)