使用 3D 資訊方塊轉譯器

擬真成像 3D 圖塊採用 OGC 標準 glTF 格式,也就是說,您可以使用任何支援 OGC 3D 圖塊規格的轉譯器來建立 3D 視覺化內容。舉例來說,Cesium 是轉譯 3D 視覺化內容的基礎開放原始碼程式庫。

使用 CesiumJS

CesiumJS 是開放原始碼的 JavaScript 程式庫,可用於在網路上 3D 視覺化功能。 如要進一步瞭解如何使用 CesiumJS,請參閱「瞭解 CesiumJS」。

使用者控制項

CesiumJS 資訊方塊轉譯器具有一組標準使用者控制項。

動作 說明
平移檢視畫面 按住並拖曳
縮放檢視 按住並拖曳或滾動滑鼠滾輪
旋轉檢視 Ctrl + 向左/向右鍵並拖曳,或中鍵按住並拖曳

最佳做法

您可以採用幾種方法來縮短 CesiumJS 3D 載入時間。例如:

  • 將下列陳述式加入轉譯的 HTML,即可啟用同時要求:

    Cesium.RequestScheduler.requestsByServer["tile.googleapis.com:443"] = <REQUEST_COUNT>
    

    REQUEST_COUNT 值越高,資訊方塊的載入速度就越快。不過,如果在 REQUEST_COUNT 大於 10 且快取停用的情況下載入 Chrome 瀏覽器,可能會遇到已知的 Chrome 問題。在多數情況下,建議將 REQUEST_COUNT 設為 18 以獲得最佳效能。

  • 啟用略過詳細層級。詳情請參閱這個 Cesium 問題

請務必啟用 showCreditsOnScreen: true,才能正確顯示資料出處。詳情請參閱政策

顯示指標

如要找出影格速率,請查看系統呼叫 requestAnimationFrame 方法的每秒次數。

如要瞭解影格延遲時間的計算方式,請參閱 PerformanceDisplay 類別。

CesiumJS 轉譯器範例

如要將 CesiumJS 轉譯器與 Map Tiles API 3D 圖塊搭配使用,只要提供根圖塊網址即可。

簡易範例

下列範例會初始化 CesiumJS 轉譯器,然後載入根圖塊集。

<!DOCTYPE html>
<head>
  <meta charset="utf-8">
  <title>CesiumJS 3D Tiles Simple Demo</title>
  <script src="https://ajax.googleapis.com/ajax/libs/cesiumjs/1.105/Build/Cesium/Cesium.js"></script>
  <link href="https://ajax.googleapis.com/ajax/libs/cesiumjs/1.105/Build/Cesium/Widgets/widgets.css" rel="stylesheet">
</head>
<body>
  <div id="cesiumContainer"></div>
  <script>

    // Enable simultaneous requests.
    Cesium.RequestScheduler.requestsByServer["tile.googleapis.com:443"] = 18;

    // Create the viewer.
    const viewer = new Cesium.Viewer('cesiumContainer', {
      imageryProvider: false,
      baseLayerPicker: false,
      geocoder: false,
      globe: false,
      // https://cesium.com/blog/2018/01/24/cesium-scene-rendering-performance/#enabling-request-render-mode
      requestRenderMode: true,
    });

    // Add 3D Tiles tileset.
    const tileset = viewer.scene.primitives.add(new Cesium.Cesium3DTileset({
      url: "https://tile.googleapis.com/v1/3dtiles/root.json?key=YOUR_API_KEY",
      // This property is needed to appropriately display attributions
      // as required.
      showCreditsOnScreen: true,
    }));
  </script>
</body>

如要進一步瞭解 requestRenderMode,請參閱啟用要求轉譯模式

HTML 網頁如下所示。

Places API 整合

您可以將 CesiumJS 與 Places API 搭配使用,以擷取更多資訊。您可以使用 Autocomplete 小工具,前往地點的可視區域。此範例使用 Places Autocomplete API (按照這些操作說明啟用),以及 Maps JavaScript API (如按照這些操作說明啟用)。

<!DOCTYPE html>
<head>
 <meta charset="utf-8" />
 <title>CesiumJS 3D Tiles Places API Integration Demo</title>
 <script src="https://ajax.googleapis.com/ajax/libs/cesiumjs/1.105/Build/Cesium/Cesium.js"></script>
 <link href="https://ajax.googleapis.com/ajax/libs/cesiumjs/1.105/Build/Cesium/Widgets/widgets.css" rel="stylesheet">
</head>
<body>
 <label for="pacViewPlace">Go to a place: </label>
 <input
   type="text"
   id="pacViewPlace"
   name="pacViewPlace"
   placeholder="Enter a location..."
   style="width: 300px"
 />
 <div id="cesiumContainer"></div>
 <script>
   // Enable simultaneous requests.
   Cesium.RequestScheduler.requestsByServer["tile.googleapis.com:443"] = 18;

   // Create the viewer.
   const viewer = new Cesium.Viewer("cesiumContainer", {
     imageryProvider: false,
     baseLayerPicker: false,
     requestRenderMode: true,
     geocoder: false,
     globe: false,
   });

   // Add 3D Tiles tileset.
   const tileset = viewer.scene.primitives.add(
     new Cesium.Cesium3DTileset({
       url: "https://tile.googleapis.com/v1/3dtiles/root.json?key=YOUR_API_KEY",
       // This property is required to display attributions as required.
       showCreditsOnScreen: true,
     })
   );

   const zoomToViewport = (viewport) => {
     viewer.entities.add({
       polyline: {
         positions: Cesium.Cartesian3.fromDegreesArray([
           viewport.getNorthEast().lng(), viewport.getNorthEast().lat(),
           viewport.getSouthWest().lng(), viewport.getNorthEast().lat(),
           viewport.getSouthWest().lng(), viewport.getSouthWest().lat(),
           viewport.getNorthEast().lng(), viewport.getSouthWest().lat(),
           viewport.getNorthEast().lng(), viewport.getNorthEast().lat(),
         ]),
         width: 10,
         clampToGround: true,
         material: Cesium.Color.RED,
       },
     });
     viewer.flyTo(viewer.entities);
   };

   function initAutocomplete() {
     const autocomplete = new google.maps.places.Autocomplete(
       document.getElementById("pacViewPlace"),
       {
         fields: [
           "geometry",
           "name",
         ],
       }
     );
     autocomplete.addListener("place_changed", () => {
       viewer.entities.removeAll();
       const place = autocomplete.getPlace();
       if (!place.geometry || !place.geometry.viewport) {
         window.alert("No viewport for input: " + place.name);
         return;
       }
       zoomToViewport(place.geometry.viewport);
     });
   }
 </script>
 <script
   async=""
   src="https://maps.googleapis.com/maps/api/js?key=YOUR_API_KEY&libraries=places&callback=initAutocomplete"
 ></script>
</body>

旋轉無人機檢視畫面

您可以控制攝影機,讓攝影機透過圖塊播放動畫。與 Places API 和 Elevation API 搭配使用時,下方動畫會模擬任何搜尋點的互動式無人機飛行。

此程式碼範例可帶您前往您在 Autocomplete 小工具中選取的地點。

<!DOCTYPE html>
<head>
  <meta charset="utf-8" />
  <title>CesiumJS 3D Tiles Rotating Drone View Demo</title>
  <script src="https://ajax.googleapis.com/ajax/libs/cesiumjs/1.105/Build/Cesium/Cesium.js"></script>
  <link href="https://ajax.googleapis.com/ajax/libs/cesiumjs/1.105/Build/Cesium/Widgets/widgets.css" rel="stylesheet">
</head>
<body>
  <label for="pacViewPlace">Go to a place: </label>
  <input type="text" id="pacViewPlace" name="pacViewPlace" placeholder="Enter a location..." style="width: 300px" />
  <div id="cesiumContainer"></div>
  <script>
    // Enable simultaneous requests.
    Cesium.RequestScheduler.requestsByServer["tile.googleapis.com:443"] = 18;

    // Create the viewer and remove unneeded options.
    const viewer = new Cesium.Viewer("cesiumContainer", {
      imageryProvider: false,
      baseLayerPicker: false,
      homeButton: false,
      fullscreenButton: false,
      navigationHelpButton: false,
      vrButton: false,
      sceneModePicker: false,
      geocoder: false,
      globe: false,
      infobox: false,
      selectionIndicator: false,
      timeline: false,
      projectionPicker: false,
      clockViewModel: null,
      animation: false,
      requestRenderMode: true,
    });

    // Add 3D Tile set.
    const tileset = viewer.scene.primitives.add(
      new Cesium.Cesium3DTileset({
        url: "https://tile.googleapis.com/v1/3dtiles/root.json?key=YOUR_API_KEY",
        // This property is required to display attributions.
        showCreditsOnScreen: true,
      })
    );

    // Point the camera at a location and elevation, at a viewport-appropriate distance.
    function pointCameraAt(location, viewport, elevation) {
      const distance = Cesium.Cartesian3.distance(
        Cesium.Cartesian3.fromDegrees(
          viewport.getSouthWest().lng(), viewport.getSouthWest().lat(), elevation),
        Cesium.Cartesian3.fromDegrees(
          viewport.getNorthEast().lng(), viewport.getNorthEast().lat(), elevation)
      ) / 2;
      const target = new Cesium.Cartesian3.fromDegrees(location.lng(), location.lat(), elevation);
      const pitch = -Math.PI / 4;
      const heading = 0;
      viewer.camera.lookAt(target, new Cesium.HeadingPitchRange(heading, pitch, distance));
    }

    // Rotate the camera around a location and elevation, at a viewport-appropriate distance.
    let unsubscribe = null;
    function rotateCameraAround(location, viewport, elevation) {
      if(unsubscribe) unsubscribe();
      pointCameraAt(location, viewport, elevation);
      unsubscribe = viewer.clock.onTick.addEventListener(() => {
        viewer.camera.rotate(Cesium.Cartesian3.UNIT_Z);
      });
    }

    function initAutocomplete() {
      const autocomplete = new google.maps.places.Autocomplete(
        document.getElementById("pacViewPlace"), {
          fields: [
            "geometry",
            "name",
          ],
        }
      );
      
      autocomplete.addListener("place_changed", async () => {
        const place = autocomplete.getPlace();
        
        if (!(place.geometry && place.geometry.viewport && place.geometry.location)) {
          window.alert(`Insufficient geometry data for place: ${place.name}`);
          return;
        }
        // Get place elevation using the ElevationService.
        const elevatorService = new google.maps.ElevationService();
        const elevationResponse =  await elevatorService.getElevationForLocations({
          locations: [place.geometry.location],
        });

        if(!(elevationResponse.results && elevationResponse.results.length)){
          window.alert(`Insufficient elevation data for place: ${place.name}`);
          return;
        }
        const elevation = elevationResponse.results[0].elevation || 10;

        rotateCameraAround(
          place.geometry.location,
          place.geometry.viewport,
          elevation
        );
      });
    }
  </script>
  <script async src="https://maps.googleapis.com/maps/api/js?key=YOUR_API_KEY&libraries=places&callback=initAutocomplete"></script>
</body>

繪製折線和標籤

這個程式碼範例示範如何在地圖中加入折線和標籤。您可以在地圖中加入折線,藉此顯示行車和步行路線、顯示屬性界線,或計算開車和步行所需時間。您也可以在不實際轉譯場景的情況下取得屬性。

您可以帶領使用者瀏覽某地的精選導覽,或是顯示目前正在銷售的鄰近房源,然後在場景中加入看板廣告等 3D 物件。

您可以摘要行程、列出檢視的屬性,並在虛擬物件中顯示這些詳細資料。

<!DOCTYPE html>
<head>
  <meta charset="utf-8" />
  <title>CesiumJS 3D Tiles Polyline and Label Demo</title>
  <script src="https://ajax.googleapis.com/ajax/libs/cesiumjs/1.105/Build/Cesium/Cesium.js"></script>
  <link 
    href="https://ajax.googleapis.com/ajax/libs/cesiumjs/1.105/Build/Cesium/Widgets/widgets.css"
    rel="stylesheet"
  />
</head>
<body>
  <div id="cesiumContainer"></div>
  <script>
    // Enable simultaneous requests.
    Cesium.RequestScheduler.requestsByServer["tile.googleapis.com:443"] = 18;

    // Create the viewer.
    const viewer = new Cesium.Viewer("cesiumContainer", {
      imageryProvider: false,
      baseLayerPicker: false,
      requestRenderMode: true,
      geocoder: false,
      globe: false,
    });

    // Add 3D Tiles tileset.
    const tileset = viewer.scene.primitives.add(
      new Cesium.Cesium3DTileset({
        url: "https://tile.googleapis.com/v1/3dtiles/root.json?key=YOUR_API_KEY",

        // This property is required to display attributions as required.
        showCreditsOnScreen: true,
      })
    );

    // Draws a circle at the position, and a line from the previous position.
    const drawPointAndLine = (position, prevPosition) => {
      viewer.entities.removeAll();
      if (prevPosition) {
        viewer.entities.add({
          polyline: {
            positions: [prevPosition, position],
            width: 3,
            material: Cesium.Color.WHITE,
            clampToGround: true,
            classificationType: Cesium.ClassificationType.CESIUM_3D_TILE,
          },
        });
      }
      viewer.entities.add({
        position: position,
        ellipsoid: {
          radii: new Cesium.Cartesian3(1, 1, 1),
          material: Cesium.Color.RED,
        },
      });
    };

    // Compute, draw, and display the position's height relative to the previous position.
    var prevPosition;
    const processHeights = (newPosition) => {
      drawPointAndLine(newPosition, prevPosition);

      const newHeight = Cesium.Cartographic.fromCartesian(newPosition).height;
      let labelText = "Current altitude (meters above sea level):\n\t" + newHeight;
      if (prevPosition) {
        const prevHeight =
          Cesium.Cartographic.fromCartesian(prevPosition).height;
        labelText += "\nHeight from previous point (meters):\n\t" + Math.abs(newHeight - prevHeight);
      }
      viewer.entities.add({
        position: newPosition,
        label: {
          text: labelText,
          disableDepthTestDistance: Number.POSITIVE_INFINITY,
          pixelOffset: new Cesium.Cartesian2(0, -10),
          showBackground: true,
          verticalOrigin: Cesium.VerticalOrigin.BOTTOM,
        }
      });

      prevPosition = newPosition;
    };

    const handler = new Cesium.ScreenSpaceEventHandler(viewer.canvas);
    handler.setInputAction(function (event) {
      const earthPosition = viewer.scene.pickPosition(event.position);
      if (Cesium.defined(earthPosition)) {
        processHeights(earthPosition);
      }
    }, Cesium.ScreenSpaceEventType.LEFT_CLICK);
  </script>
</body>

環繞攝影機軌道

在 Cesium,可以繞著搜尋點環繞攝影機,避免與建築物衝突。或者,你也可以在相機穿過建築物時,將建築物設為透明。

首先,將攝影機鎖定到某個點,然後製作相機軌道展示您的資產。方法是搭配使用攝影機的 lookAtTransform 函式與事件監聽器,如這個程式碼範例所示。

// Lock the camera onto a point.
const center = Cesium.Cartesian3.fromRadians(
  2.4213211833389243,
  0.6171926869414084,
  3626.0426275055174
);

const transform = Cesium.Transforms.eastNorthUpToFixedFrame(center);

viewer.scene.camera.lookAtTransform(
  transform,
  new Cesium.HeadingPitchRange(0, -Math.PI / 8, 2900)
);

// Orbit around this point.
viewer.clock.onTick.addEventListener(function (clock) {
  viewer.scene.camera.rotateRight(0.005);
});

如要進一步瞭解如何控制相機,請參閱「控制相機」一文

與 Cesium for Unreal

如要將 Cesium for Unreal 外掛程式與 3D Tiles API 搭配使用,請按照下列步驟操作。

  1. 安裝 Cesium for Unreal 外掛程式。

  2. 建立新的 Unreal 專案。

  3. 連結至 Google 擬真成像 3D Tiles API。

    1. 從選單中依序選取「Cesium」 >「Cesium」,開啟 Cesium 視窗。

    2. 選取「Blank 3D Tiles Tileset」

    3. 在「World Outliner」中,選取這個 Cesium3DTileset 即可開啟「Details」面板。

    4. 將「來源」從「從 Cesium Ion」變更為「寄件者網址」

    5. 將網址設為 Google 3D 圖塊網址。

    https://tile.googleapis.com/v1/3dtiles/root.json?key=YOUR_API_KEY
    
    1. 啟用「在畫面上顯示功勞」,即可正確顯示出處。
  4. 這會載入整個世界,如要移動至任何 LatLng,請選取「Outliner」CesiumGeoreference面板中的「CesiumGeoreference」CesiumGeoreference項目,然後在「Details」CesiumGeoreference面板中編輯「Origin Latitude/Longitude/Height」CesiumGeoreference

與適用於 Unity 的 Cesium 合作

如要搭配 Unity 的 Cesium 使用擬真圖塊,請按照下列步驟操作。

  1. 建立新的 Unity 專案。

  2. 在「套件管理員」部分中新增限定範圍的登錄檔 (依序前往「Editor」 >「Project Settings」)。

    • 名稱:Cesium

    • 網址:https://unity.pkg.cesium.com

    • 範圍:com.cesium.unity

  3. 安裝適用於 Unity 套件的 Cesium。

  4. 連結至 Google Photoreal 3D Tiles API。

    1. 從選單中依序選取「Cesium」 >「Cesium」,開啟 Cesium 視窗。

    2. 按一下「空白 3D 圖塊圖塊」

    3. 在左側面板中,在「Source」下方的「Tileset Source」選項中選取「From URL」 (而不是「From Cesium Ion」)。

    4. 將網址設為 Google 3D 圖塊網址。

    https://tile.googleapis.com/v1/3dtiles/root.json?key=YOUR_API_KEY
    
    1. 啟用「在畫面上顯示功勞」,即可正確顯示出處。
  5. 這會載入整個世界,如要移動至任何 LatLng,請選取「Scene Hierarchy」(情境階層)CesiumGeoreference 中的「CesiumGeoreference」CesiumGeoreference項目,然後在「Inspector」CesiumGeoreference中編輯起點/經度/高度。

使用 deck.gl

deck.gl 採用 WebGL 技術,是一種開放原始碼 JavaScript 架構,適用於高效能的大規模資料視覺化作業。

歸因

從資訊方塊 gltf asset 擷取 copyright 欄位,然後在算繪的檢視畫面中顯示,確保您正確顯示資料出處。詳情請參閱「顯示資料出處」。

deck.gl 轉譯器範例

簡易範例

下列範例會初始化 deck.gl 轉譯器,然後載入 3D 地點。在您的程式碼中,務必將 YOUR_API_KEY 換成您實際的 API 金鑰。

<!DOCTYPE html>
<html>
 <head>
   <title>deck.gl Photorealistic 3D Tiles example</title>
   <script src="https://unpkg.com/deck.gl@latest/dist.min.js"></script>
   <style>
     body { margin: 0; padding: 0;}
     #map { position: absolute; top: 0;bottom: 0;width: 100%;}
     #credits { position: absolute; bottom: 0; right: 0; padding: 2px; font-size: 15px; color: white;
        text-shadow: -1px 0 black, 0 1px black, 1px 0 black, 0 -1px black;}
   </style>
 </head>

 <body>
   <div id="map"></div>
   <div id="credits"></div>
   <script>
     const GOOGLE_API_KEY = YOUR_API_KEY;
     const TILESET_URL = `https://tile.googleapis.com/v1/3dtiles/root.json`;
     const creditsElement = document.getElementById('credits');
     new deck.DeckGL({
       container: 'map',
       initialViewState: {
         latitude: 50.0890,
         longitude: 14.4196,
         zoom: 16,
         bearing: 90,
         pitch: 60,
         height: 200
       },
       controller: {minZoom: 8},
       layers: [
         new deck.Tile3DLayer({
           id: 'google-3d-tiles',
           data: TILESET_URL,
           loadOptions: {
            fetch: {
              headers: {
                'X-GOOG-API-KEY': GOOGLE_API_KEY
              }
            }
          },
           onTilesetLoad: tileset3d => {
             tileset3d.options. => {
               const credits = new Set();
               selectedTiles.forEach(tile => {
                 const {copyright} = tile.content.gltf.asset;
                 copyright.split(';').forEach(credits.add, credits);
                 creditsElement.innerHTML = [...credits].join('; ');
               });
               return selectedTiles;
             }
           }
         })
       ]
     });
   </script>
 </body>
</html>

在 Google 擬真成像 3D 圖塊上方視覺化 2D 圖層

deck.gl TerrainExtension 會在 3D 介面上算繪其他 2D 資料。舉例來說,您可以將建築物平面圖的 GeoJSON 繪製在擬真 3D 圖塊幾何圖形之上。

在以下範例中,系統會根據經過調整的「擬真成像 3D 圖塊」表面的多邊形來視覺化建築物圖層。

<!DOCTYPE html>
<html>
 <head>
   <title>Google 3D tiles example</title>
   <script src="https://unpkg.com/deck.gl@latest/dist.min.js"></script>
   <style>
     body { margin: 0; padding: 0;}
     #map { position: absolute; top: 0;bottom: 0;width: 100%;}
     #credits { position: absolute; bottom: 0; right: 0; padding: 2px; font-size: 15px; color: white;
        text-shadow: -1px 0 black, 0 1px black, 1px 0 black, 0 -1px black;}
   </style>
 </head>

 <body>
   <div id="map"></div>
   <div id="credits"></div>
   <script>
     const GOOGLE_API_KEY = YOUR_API_KEY;
     const TILESET_URL = `https://tile.googleapis.com/v1/3dtiles/root.json`;
     const BUILDINGS_URL = 'https://raw.githubusercontent.com/visgl/deck.gl-data/master/examples/google-3d-tiles/buildings.geojson'
     const creditsElement = document.getElementById('credits');
     const deckgl = new deck.DeckGL({
       container: 'map',
       initialViewState: {
         latitude: 50.0890,
         longitude: 14.4196,
         zoom: 16,
         bearing: 90,
         pitch: 60,
         height: 200
       },
       controller: true,
       layers: [
         new deck.Tile3DLayer({
           id: 'google-3d-tiles',
           data: TILESET_URL,
           loadOptions: {
            fetch: {
              headers: {
                'X-GOOG-API-KEY': GOOGLE_API_KEY
              }
            }
          },
          onTilesetLoad: tileset3d => {
             tileset3d.options. => {
               const credits = new Set();
               selectedTiles.forEach(tile => {
                 const {copyright} = tile.content.gltf.asset;
                 copyright.split(';').forEach(credits.add, credits);
                 creditsElement.innerHTML = [...credits].join('; ');
               });
               return selectedTiles;
             }
           },
           operation: 'terrain+draw'
         }),
         new deck.GeoJsonLayer({
           id: 'buildings',
           // This dataset is created by CARTO, using other Open Datasets available. More info at: https://3dtiles.carto.com/#about.
           data: 'https://raw.githubusercontent.com/visgl/deck.gl-data/master/examples/google-3d-tiles/buildings.geojson',
           stroked: false,
           filled: true,
           getFillColor: ({properties}) => {
             const {tpp} = properties;
             // quantiles break
             if (tpp < 0.6249)
               return [254, 246, 181]
             else if (tpp < 0.6780)
               return [255, 194, 133]
             else if (tpp < 0.8594)
               return [250, 138, 118]
             return [225, 83, 131]
           },
           opacity: 0.2,
           extensions: [new deck._TerrainExtension()]
         })
       ]
     });
   </script>
 </body>
</html>