Add experimental Cesium vehicle cruise preview

README.md

@@ -114,6 +114,12 @@ python3 -m http.server 8765
 
 然后打开 `http://localhost:8765/my-area-cesium-preview.html`。
 
+## 实验：车辆巡航
+
+`preview` 和 `cesium` 阶段会额外生成 `<area-id>-vehicle-route.json`。该文件从 OSM bounds 内的可行驶 `highway` way 提取道路中心线，Cesium 预览页会加载最长道路段并显示一辆实验车辆循环巡航。
+
+这是用于验证高精度巡航可用性的预览层功能，不会改变 Blender/GLB 资产本身。
+
 ## 已沉淀区域
 
 - `config/areas/nantaizi-lake-innovation-valley.json`

docs/changelog.md

@@ -2,6 +2,7 @@
 
 ## 2026-07-27
 
+- 实验分支新增 Cesium 车辆巡航预览：从 OSM 可行驶 `highway` 提取 bounds 内路线，输出 `<area-id>-vehicle-route.json`，并在预览页中驱动车辆循环移动。
 - 将项目主入口重构为区域资产管线：`scripts/build-area.js`。
 - 新增 `config/areas/nantaizi-lake-innovation-valley.json` 和 `config/areas/hanyang-block.json`，支持按 OSM 输入生成独立输出目录。
 - `npm run build` 现在默认走区域资产管线；旧 QGIS 管线保留为 `npm run build:qgis`。

scripts/build-area.js

@@ -82,6 +82,7 @@ function normalizeAreaConfig(raw) {
     cesiumPreview: path.resolve(
       outputOverrides.cesiumPreview || path.join(areaDir, `${fileStem}-cesium-preview.html`),
     ),
+    vehicleRoute: path.resolve(outputOverrides.vehicleRoute || path.join(areaDir, `${fileStem}-vehicle-route.json`)),
     pipelineDir: path.resolve(outputOverrides.pipelineDir || path.join(areaDir, "_pipeline")),
   };
 
@@ -272,13 +273,168 @@ function writeCesiumPreview(area) {
   ensureFile(area.outputs.metadata, "Cesium metadata");
   const htmlPath = area.outputs.cesiumPreview;
   fs.mkdirSync(path.dirname(htmlPath), { recursive: true });
+  writeVehicleRoute(area);
   const glbName = path.basename(area.outputs.glb);
   const metadataName = path.basename(area.outputs.metadata);
-  fs.writeFileSync(htmlPath, cesiumPreviewHtml(glbName, metadataName, area.id));
+  const routeName = path.basename(area.outputs.vehicleRoute);
+  fs.writeFileSync(htmlPath, cesiumPreviewHtml(glbName, metadataName, routeName, area.id));
   console.log(`Cesium preview: ${htmlPath}`);
 }
 
-function cesiumPreviewHtml(glbName, metadataName, areaId) {
+function writeVehicleRoute(area) {
+  const route = buildVehicleRoute(area.input);
+  fs.mkdirSync(path.dirname(area.outputs.vehicleRoute), { recursive: true });
+  fs.writeFileSync(area.outputs.vehicleRoute, `${JSON.stringify(route, null, 2)}\n`);
+  console.log(`Vehicle route: ${area.outputs.vehicleRoute}`);
+}
+
+function buildVehicleRoute(osmPath) {
+  const xml = fs.readFileSync(osmPath, "utf8");
+  const bounds = osmBounds(xml);
+  const nodes = new Map();
+  for (const match of xml.matchAll(/<node\b([^>]*)>/g)) {
+    const attrs = xmlAttrs(match[1]);
+    if (!attrs.id || attrs.lon === undefined || attrs.lat === undefined) continue;
+    nodes.set(attrs.id, [Number(attrs.lon), Number(attrs.lat)]);
+  }
+
+  const segments = [];
+  for (const match of xml.matchAll(/<way\b([^>]*)>([\s\S]*?)<\/way>/g)) {
+    const attrs = xmlAttrs(match[1]);
+    const body = match[2];
+    const tags = {};
+    for (const tagMatch of body.matchAll(/<tag\b([^>]*)\/?>/g)) {
+      const tag = xmlAttrs(tagMatch[1]);
+      if (tag.k) tags[tag.k] = tag.v || "";
+    }
+    if (!isCruiseHighway(tags)) continue;
+    const coords = [];
+    for (const ndMatch of body.matchAll(/<nd\b([^>]*)\/?>/g)) {
+      const nd = xmlAttrs(ndMatch[1]);
+      const coord = nodes.get(nd.ref);
+      if (coord) coords.push(coord);
+    }
+    const runs = splitInBounds(compactCoords(coords), bounds);
+    let runIndex = 0;
+    for (const run of runs) {
+      const lengthMeters = routeLength(run);
+      if (lengthMeters < 20) continue;
+      runIndex += 1;
+      segments.push({
+        id: runIndex === 1 ? (attrs.id || `way-${segments.length + 1}`) : `${attrs.id || "way"}-${runIndex}`,
+        name: tags.name || tags.highway || "road",
+        highway: tags.highway || "",
+        oneWay: tags.oneway || "",
+        lengthMeters,
+        coordinates: run,
+      });
+    }
+  }
+  segments.sort((a, b) => b.lengthMeters - a.lengthMeters);
+  return {
+    source: osmPath,
+    bounds,
+    generatedAt: new Date().toISOString(),
+    speedMetersPerSecond: 8.0,
+    loop: true,
+    segments,
+  };
+}
+
+function osmBounds(xml) {
+  const match = xml.match(/<bounds\b([^>]*)\/?>/);
+  if (!match) return null;
+  const attrs = xmlAttrs(match[1]);
+  const bounds = {
+    minLon: Number(attrs.minlon),
+    minLat: Number(attrs.minlat),
+    maxLon: Number(attrs.maxlon),
+    maxLat: Number(attrs.maxlat),
+  };
+  return Object.values(bounds).every(Number.isFinite) ? bounds : null;
+}
+
+function xmlAttrs(text) {
+  const attrs = {};
+  for (const match of text.matchAll(/([:\w-]+)\s*=\s*("([^"]*)"|'([^']*)')/g)) {
+    attrs[match[1]] = match[3] !== undefined ? match[3] : match[4];
+  }
+  return attrs;
+}
+
+function isCruiseHighway(tags) {
+  const highway = tags.highway || "";
+  if (!highway) return false;
+  if (tags.area === "yes") return false;
+  const blocked = new Set([
+    "footway", "path", "pedestrian", "steps", "cycleway", "service", "track",
+    "bridleway", "corridor", "elevator", "platform", "construction",
+  ]);
+  return !blocked.has(highway);
+}
+
+function compactCoords(coords) {
+  const out = [];
+  for (const coord of coords) {
+    const last = out[out.length - 1];
+    if (!last || last[0] !== coord[0] || last[1] !== coord[1]) {
+      out.push(coord);
+    }
+  }
+  return out;
+}
+
+function splitInBounds(coords, bounds) {
+  if (!bounds) return [coords];
+  const runs = [];
+  let current = [];
+  for (const coord of coords) {
+    if (insideBounds(coord, bounds)) {
+      current.push(coord);
+    } else if (current.length) {
+      if (current.length >= 2) runs.push(current);
+      current = [];
+    }
+  }
+  if (current.length >= 2) runs.push(current);
+  return runs;
+}
+
+function insideBounds(coord, bounds) {
+  const pad = 0.00002;
+  return (
+    coord[0] >= bounds.minLon - pad &&
+    coord[0] <= bounds.maxLon + pad &&
+    coord[1] >= bounds.minLat - pad &&
+    coord[1] <= bounds.maxLat + pad
+  );
+}
+
+function routeLength(coords) {
+  let total = 0;
+  for (let i = 1; i < coords.length; i += 1) {
+    total += haversineMeters(coords[i - 1], coords[i]);
+  }
+  return total;
+}
+
+function haversineMeters(a, b) {
+  const radius = 6371008.8;
+  const lat1 = degreesToRadians(a[1]);
+  const lat2 = degreesToRadians(b[1]);
+  const dLat = degreesToRadians(b[1] - a[1]);
+  const dLon = degreesToRadians(b[0] - a[0]);
+  const sinLat = Math.sin(dLat / 2);
+  const sinLon = Math.sin(dLon / 2);
+  const h = sinLat * sinLat + Math.cos(lat1) * Math.cos(lat2) * sinLon * sinLon;
+  return 2 * radius * Math.asin(Math.min(1, Math.sqrt(h)));
+}
+
+function degreesToRadians(value) {
+  return value * Math.PI / 180;
+}
+
+function cesiumPreviewHtml(glbName, metadataName, routeName, areaId) {
   return `<!doctype html>
 <html lang="zh-CN">
 <head>
@@ -308,17 +464,52 @@ function cesiumPreviewHtml(glbName, metadataName, areaId) {
       font-size: 12px;
       line-height: 1.45;
     }
+    #controls {
+      position: absolute;
+      top: 12px;
+      left: 12px;
+      z-index: 1;
+      display: flex;
+      gap: 8px;
+      align-items: center;
+      padding: 8px;
+      border-radius: 4px;
+      background: rgba(20, 24, 28, 0.78);
+      color: #fff;
+      font-size: 12px;
+    }
+    #controls button {
+      height: 28px;
+      border: 0;
+      border-radius: 4px;
+      padding: 0 10px;
+      background: #f2f5f7;
+      color: #111;
+      cursor: pointer;
+    }
+    #controls input {
+      width: 120px;
+    }
   </style>
 </head>
 <body>
   <div id="cesiumContainer"></div>
+  <div id="controls">
+    <button id="toggleCruise">Pause</button>
+    <label>Speed <input id="speedControl" type="range" min="2" max="22" step="1" value="8"></label>
+    <span id="speedLabel">8 m/s</span>
+  </div>
   <div id="status">Loading ${escapeHtml(glbName)}...</div>
   <script>
     const statusEl = document.getElementById("status");
+    const toggleCruise = document.getElementById("toggleCruise");
+    const speedControl = document.getElementById("speedControl");
+    const speedLabel = document.getElementById("speedLabel");
     Cesium.Ion.defaultAccessToken = "";
 
     async function main() {
       const metadata = await fetch("${escapeJs(metadataName)}").then((r) => r.json());
+      const routeData = await fetch("${escapeJs(routeName)}").then((r) => r.json());
       const anchor = metadata.anchor || {};
       const longitude = Number(anchor.longitude || 0);
       const latitude = Number(anchor.latitude || 0);
@@ -350,13 +541,105 @@ function cesiumPreviewHtml(glbName, metadataName, areaId) {
         scale: 1.0
       });
       viewer.scene.primitives.add(model);
+      const cruise = addVehicleCruise(viewer, routeData);
 
       const center = Cesium.Cartesian3.fromDegrees(longitude, latitude, height);
       viewer.camera.flyToBoundingSphere(
         new Cesium.BoundingSphere(center, 900.0),
         { duration: 0.0 }
       );
-      statusEl.textContent = "${escapeJs(glbName)} | " + longitude.toFixed(6) + ", " + latitude.toFixed(6);
+      statusEl.textContent = "${escapeJs(glbName)} | route " + cruise.segment.id + " | " + Math.round(cruise.segment.lengthMeters) + "m";
+    }
+
+    function addVehicleCruise(viewer, routeData) {
+      const segment = (routeData.segments || [])[0];
+      if (!segment || !segment.coordinates || segment.coordinates.length < 2) {
+        throw new Error("No drivable route found in ${escapeJs(routeName)}");
+      }
+      const speed = Number(routeData.speedMetersPerSecond || 8);
+      const start = Cesium.JulianDate.now();
+      const duration = Math.max(8, segment.lengthMeters / speed);
+      const stop = Cesium.JulianDate.addSeconds(start, duration, new Cesium.JulianDate());
+      const positions = new Cesium.SampledPositionProperty();
+      let elapsed = 0;
+      let previous = segment.coordinates[0];
+      positions.addSample(start, Cesium.Cartesian3.fromDegrees(previous[0], previous[1], 1.15));
+      for (let i = 1; i < segment.coordinates.length; i += 1) {
+        const coord = segment.coordinates[i];
+        elapsed += distanceMeters(previous, coord) / speed;
+        const time = Cesium.JulianDate.addSeconds(start, elapsed, new Cesium.JulianDate());
+        positions.addSample(time, Cesium.Cartesian3.fromDegrees(coord[0], coord[1], 1.15));
+        previous = coord;
+      }
+      positions.setInterpolationOptions({
+        interpolationDegree: 1,
+        interpolationAlgorithm: Cesium.LinearApproximation
+      });
+
+      viewer.clock.startTime = start.clone();
+      viewer.clock.stopTime = stop.clone();
+      viewer.clock.currentTime = start.clone();
+      viewer.clock.clockRange = Cesium.ClockRange.LOOP_STOP;
+      viewer.clock.multiplier = 1;
+      viewer.clock.shouldAnimate = true;
+
+      const flat = [];
+      for (const coord of segment.coordinates) {
+        flat.push(coord[0], coord[1], 1.05);
+      }
+      viewer.entities.add({
+        name: "Cruise route",
+        polyline: {
+          positions: Cesium.Cartesian3.fromDegreesArrayHeights(flat),
+          width: 4,
+          material: Cesium.Color.CYAN.withAlpha(0.85),
+          clampToGround: false
+        }
+      });
+      const vehicle = viewer.entities.add({
+        name: "Cruise vehicle",
+        availability: new Cesium.TimeIntervalCollection([
+          new Cesium.TimeInterval({ start, stop })
+        ]),
+        position: positions,
+        orientation: new Cesium.VelocityOrientationProperty(positions),
+        box: {
+          dimensions: new Cesium.Cartesian3(4.6, 1.9, 1.5),
+          material: Cesium.Color.ORANGERED,
+          outline: true,
+          outlineColor: Cesium.Color.WHITE
+        },
+        path: {
+          resolution: 1,
+          leadTime: 4,
+          trailTime: 10,
+          width: 2,
+          material: Cesium.Color.ORANGE.withAlpha(0.9)
+        }
+      });
+      toggleCruise.addEventListener("click", () => {
+        viewer.clock.shouldAnimate = !viewer.clock.shouldAnimate;
+        toggleCruise.textContent = viewer.clock.shouldAnimate ? "Pause" : "Play";
+      });
+      speedControl.addEventListener("input", () => {
+        const value = Number(speedControl.value);
+        viewer.clock.multiplier = value / speed;
+        speedLabel.textContent = value + " m/s";
+      });
+      viewer.trackedEntity = vehicle;
+      return { segment, vehicle };
+    }
+
+    function distanceMeters(a, b) {
+      const radius = 6371008.8;
+      const lat1 = Cesium.Math.toRadians(a[1]);
+      const lat2 = Cesium.Math.toRadians(b[1]);
+      const dLat = Cesium.Math.toRadians(b[1] - a[1]);
+      const dLon = Cesium.Math.toRadians(b[0] - a[0]);
+      const sinLat = Math.sin(dLat / 2);
+      const sinLon = Math.sin(dLon / 2);
+      const h = sinLat * sinLat + Math.cos(lat1) * Math.cos(lat2) * sinLon * sinLon;
+      return 2 * radius * Math.asin(Math.min(1, Math.sqrt(h)));
     }
 
     main().catch((error) => {