Pick objects with various methods (GPU picking, raycasting...)

Picking
?

Picking lets you pick Giro3D and native THREE.js objects, and get their coordinates in the CRS of the instance.
Provides various filtering options to enhance precision and performance.

  • pixels
  • Pick latency: 12.1 ms
  • No result to display
100% © IGN

Picking is the action of determining what's underneath the mouse cursor.

index.js
import {
  Vector3,
  Group,
  Mesh,
  BoxGeometry,
  SphereGeometry,
  MeshLambertMaterial,
  DirectionalLight,
  AmbientLight,
} from "three";
import { MapControls } from "three/examples/jsm/controls/MapControls.js";

import Extent from "@giro3d/giro3d/core/geographic/Extent.js";
import Instance from "@giro3d/giro3d/core/Instance.js";
import Map from "@giro3d/giro3d/entities/Map.js";
import Tiles3D from "@giro3d/giro3d/entities/Tiles3D.js";
import ColorLayer from "@giro3d/giro3d/core/layer/ColorLayer.js";
import ElevationLayer from "@giro3d/giro3d/core/layer/ElevationLayer.js";
import BilFormat from "@giro3d/giro3d/formats/BilFormat.js";
import Tiles3DSource from "@giro3d/giro3d/sources/Tiles3DSource.js";
import Inspector from "@giro3d/giro3d/gui/Inspector.js";
import WmtsSource from "@giro3d/giro3d/sources/WmtsSource.js";
import PointCloudMaterial from "@giro3d/giro3d/renderer/PointCloudMaterial.js";

import { bindDropDown } from "./widgets/bindDropDown";
import { bindSlider } from "./widgets/bindSlider";
import { bindToggle } from "./widgets/bindToggle";

Instance.registerCRS(
  "EPSG:2154",
  "+proj=lcc +lat_0=46.5 +lon_0=3 +lat_1=49 +lat_2=44 +x_0=700000 +y_0=6600000 +ellps=GRS80 +towgs84=0,0,0,0,0,0,0 +units=m +no_defs +type=crs",
);
Instance.registerCRS(
  "IGNF:WGS84G",
  'GEOGCS["GCS_WGS_1984",DATUM["D_WGS_1984",SPHEROID["WGS_1984",6378137.0,298.257223563]],PRIMEM["Greenwich",0.0],UNIT["Degree",0.0174532925199433]]',
);

const extent = new Extent(
  "EPSG:2154",
  -111629.52,
  1275028.84,
  5976033.79,
  7230161.64,
);

const instance = new Instance({
  target: "view",
  crs: extent.crs,
  backgroundColor: 0xcccccc,
});

instance.renderingOptions.enableEDL = true;
instance.renderingOptions.enableInpainting = true;
instance.renderingOptions.enablePointCloudOcclusion = true;

const map = new Map({
  extent,
  backgroundColor: "gray",
  hillshading: {
    enabled: true,
    elevationLayersOnly: true,
  },
});

instance.add(map);

const noDataValue = -1000;

const capabilitiesUrl =
  "https://data.geopf.fr/wmts?SERVICE=WMTS&VERSION=1.0.0&REQUEST=GetCapabilities";

WmtsSource.fromCapabilities(capabilitiesUrl, {
  layer: "ELEVATION.ELEVATIONGRIDCOVERAGE.HIGHRES",
  format: new BilFormat(),
  noDataValue,
})
  .then((elevationWmts) => {
    map.addLayer(
      new ElevationLayer({
        name: "wmts_elevation",
        extent: map.extent,
        // We don't need the full resolution of terrain because we are not using any shading
        resolutionFactor: 0.25,
        minmax: { min: 0, max: 5000 },
        noDataOptions: {
          replaceNoData: false,
        },
        source: elevationWmts,
      }),
    );
  })
  .catch(console.error);

WmtsSource.fromCapabilities(capabilitiesUrl, {
  layer: "HR.ORTHOIMAGERY.ORTHOPHOTOS",
})
  .then((orthophotoWmts) => {
    map.addLayer(
      new ColorLayer({
        name: "wmts_orthophotos",
        extent: map.extent,
        source: orthophotoWmts,
      }),
    );
  })
  .catch(console.error);

// Create the 3D tiles entity
const pointcloud = new Tiles3D(
  new Tiles3DSource("https://3d.oslandia.com/lidar_hd/tileset.json"),
  {
    material: new PointCloudMaterial(),
  },
);

instance.add(pointcloud);

// Add a sunlight
const sun = new DirectionalLight("#ffffff", 1.4);
sun.position.set(-1, -2, 1).normalize();
sun.updateMatrixWorld(true);
instance.scene.add(sun);

// We can look below the floor, so let's light also a bit there
const sun2 = new DirectionalLight("#ffffff", 0.5);
sun2.position.set(0, 1, 1);
sun2.updateMatrixWorld();
instance.scene.add(sun2);

// Add an ambient light
const ambientLight = new AmbientLight(0xffffff, 0.2);
instance.scene.add(ambientLight);

const cube = new Mesh(
  new BoxGeometry(300, 300, 300),
  new MeshLambertMaterial({ color: "blue" }),
);
cube.name = "cube";

cube.position.set(913741, 6459089, 369);
instance.add(cube);
cube.updateMatrixWorld(true);

const lookAt = new Vector3(913896, 6459191, 200);

instance.view.camera.position.set(
  913349.2364044407,
  6456426.459171033,
  1706.0108044011636,
);
instance.view.camera.lookAt(lookAt);

const controls = new MapControls(instance.view.camera, instance.domElement);
controls.target.copy(lookAt);
controls.saveState();
controls.enableDamping = true;
controls.dampingFactor = 0.2;
instance.view.setControls(controls);

const markerMaterial = new MeshLambertMaterial({
  color: "red",
});

const markerGroup = new Group();
instance.add(markerGroup);

const options = {
  gpuPicking: false,
  showMarkers: true,
  pickPointCloudOnly: false,
  pickMapOnly: false,
  radius: 0,
  limit: 0,
  pickEvent: "mousemove",
};

bindDropDown("pickEvent", (v) => (options.pickEvent = v));

bindToggle("gpuPicking", (v) => (options.gpuPicking = v));
bindToggle("showMarkers", (v) => {
  options.showMarkers = v;
  if (!v) {
    markerGroup.clear();
    instance.notifyChange();
  }
});
bindToggle("pickMap", (v) => (options.pickMapOnly = v));
bindToggle("pickPointCloud", (v) => (options.pickPointCloudOnly = v));

bindSlider("radius", (v) => (options.radius = v));
bindSlider("limit", (v) => (options.limit = v));

function updateResultTable(pickResults) {
  const table = document.getElementById("table");
  const resultList = document.getElementById("results");

  resultList.innerHTML = "";

  function column(content) {
    const col = document.createElement("td");
    col.innerHTML = content;
    return col;
  }

  const emptyWarning = document.getElementById("emptyWarning");
  if (pickResults.length > 0) {
    emptyWarning.style.display = "none";
    table.style.display = "unset";
  } else {
    emptyWarning.style.display = "unset";
    table.style.display = "none";
  }

  for (let index = 0; index < pickResults.length; index++) {
    const pickResult = pickResults[index];
    const tr = document.createElement("tr");

    // result #
    tr.appendChild(column(`${index}`));
    // entity
    const entity = pickResult.entity;
    tr.appendChild(
      column(entity ? `<code>${pickResult.entity?.id}</code>` : "none"),
    );
    // picked object
    const type = pickResult.object.type;
    tr.appendChild(
      column(`<span class="badge rounded-pill text-bg-primary">${type}</span>`),
    );

    const point = pickResult.point;

    // X, Y, Z coordinates of point
    tr.appendChild(column(point.x.toFixed(0)));
    tr.appendChild(column(point.y.toFixed(0)));
    tr.appendChild(column(point.z.toFixed(0)));

    resultList.appendChild(tr);
  }
}

const sphere = new SphereGeometry(8);

function performPicking(mouseEvent) {
  // Determine which entities to include
  let where = [];
  if (options.pickMapOnly) {
    where.push(map);
  }

  if (options.pickPointCloudOnly) {
    where.push(pointcloud);
  }

  const pickOptions = {
    limit: options.limit === 0 ? undefined : options.limit,
    radius: options.radius,
    gpuPicking: options.gpuPicking,
    where: where.length > 0 ? where : undefined,
    sortByDistance: true,
  };

  const start = performance.now();
  const results = instance.pickObjectsAt(mouseEvent, pickOptions);
  const end = performance.now();

  document.getElementById("latency").innerText =
    `Latency: ${(end - start).toFixed(1)} ms`;

  const noRaycast = () => {};

  if (options.showMarkers && results.length > 0) {
    const position = results[0].point;
    const marker = new Mesh(sphere, markerMaterial);
    // Disable raycasting on markers to avoid picking them.
    marker.raycast = noRaycast;
    if (markerGroup.children.length > 30) {
      const removed = markerGroup.children.splice(
        0,
        markerGroup.children.length - 30,
      );
      removed.forEach((item) => item.removeFromParent());
    }

    // - In the case of CPU picking, the Z value is simply the Z-coordinate of
    // the picked point, which itself is affected by the scale of the scene.
    //
    // - In the case of GPU picking, the Z value is sampled from the texture, unaffected
    // by the scale of the scene. That is why we have to apply the scene scale to obtain the
    // correct world space coordinate.
    if (options.gpuPicking) {
      position.multiply(instance.scene.scale);
    }

    marker.position.copy(position);
    // Notice we use attach instead of add so that world position is
    // preserved in case of non-default scale.
    markerGroup.attach(marker);
    marker.updateMatrixWorld(true);
    instance.notifyChange();
  }

  updateResultTable(results);
}

function onMouseMove(mouseEvent) {
  if (options.pickEvent === "mousemove") {
    performPicking(mouseEvent);
  }
}

function onMouseClick(mouseEvent) {
  if (options.pickEvent === "click") {
    performPicking(mouseEvent);
  }
}

bindSlider("zScaleSlider", (v) => {
  document.getElementById("zScaleLabel").innerText =
    `Z-scale = ${v.toFixed(1)}`;

  instance.scene.scale.setZ(v);
  instance.scene.updateMatrixWorld(true);
  instance.notifyChange(map);
});

instance.domElement.addEventListener("mousemove", onMouseMove);
instance.domElement.addEventListener("click", onMouseClick);

instance.scene.updateMatrixWorld(true);

instance.notifyChange();

Inspector.attach("inspector", instance);
index.html
<!doctype html>
<html lang="en">
  <head>
    <title>Picking</title>
    <meta charset="UTF-8" />
    <meta name="name" content="picking" />
    <meta
      name="description"
      content="Pick objects with various methods (GPU picking, raycasting...)"
    />
    <meta name="viewport" content="width=device-width, initial-scale=1.0" />

    <link rel="icon" href="https://giro3d.org/images/favicon.svg" />
    <link
      href="https://giro3d.org/assets/bootstrap-custom.css"
      rel="stylesheet"
    />
    <script src="https://giro3d.org/assets/bootstrap.bundle.min.js"></script>
    <link
      rel="stylesheet"
      type="text/css"
      href="https://giro3d.org/latest/examples/css/example.css"
    />
  </head>

  <body>
    <div id="view" class="m-0 p-0 w-100 h-100"></div>
    <div
      id="inspector"
      class="position-absolute top-0 start-0 mh-100 overflow-auto"
    ></div>

    <div class="side-pane-with-status-bar" style="width: 30rem">
      <div class="card">
        <h5 class="card-header">Picking</h5>

        <!-- tooltip -->
        <span
          class="badge bg-secondary position-absolute top-0 end-0 m-2"
          data-bs-toggle="popover"
          data-bs-content="pickingHelper"
          >?</span
        >
        <p class="card-text d-none" id="pickingHelper">
          Picking lets you pick Giro3D and native THREE.js objects, and get
          their coordinates in the CRS of the instance.<br />
          Provides various filtering options to enhance precision and
          performance.
        </p>

        <div class="card-body p-0">
          <ul class="list-group list-group-flush">
            <li class="list-group-item">
              <!-- Parameters -->
              <form>
                <!-- Z-scale -->
                <div class="mb-2">
                  <label
                    for="zScaleSlider"
                    class="col-form-label"
                    id="zScaleLabel"
                    >Z-scale = 1</label
                  >
                  <div class="input-group">
                    <input
                      type="range"
                      min="0.1"
                      max="4"
                      step="0.1"
                      value="1"
                      class="form-range"
                      id="zScaleSlider"
                      autocomplete="off"
                    />
                  </div>
                </div>

                <!-- Pick events -->
                <div class="mb-3">
                  <label for="pickEvent" class="form-label"
                    >Pick on event</label
                  >
                  <select id="pickEvent" class="form-select">
                    <option value="click">Click</option>
                    <option value="mousemove" selected>Mouse move</option>
                  </select>
                </div>
                <!-- Picking radius -->
                <div class="mb-3">
                  <label for="radius" class="col-form-label"
                    >Picking radius</label
                  >
                  <div class="input-group">
                    <input
                      id="radius"
                      type="number"
                      min="0"
                      max="10"
                      value="0"
                      class="form-control"
                    />
                    <span class="input-group-text">pixels</span>
                  </div>
                </div>
                <!-- Limit -->
                <div class="mb-3">
                  <label for="limit" class="col-form-label"
                    >Number of objects (0 for all)</label
                  >
                  <input
                    id="limit"
                    type="number"
                    min="0"
                    max="100"
                    value="0"
                    class="form-control"
                  />
                </div>

                <div class="row">
                  <!-- Prefer raycasting -->
                  <div class="col">
                    <div class="form-check">
                      <input
                        class="form-check-input"
                        type="checkbox"
                        id="gpuPicking"
                      />
                      <label class="form-check-label" for="gpuPicking">
                        GPU picking
                      </label>
                    </div>
                  </div>

                  <!-- Picking markers -->
                  <div class="col">
                    <div class="form-check">
                      <input
                        class="form-check-input"
                        type="checkbox"
                        checked
                        id="showMarkers"
                        autocomplete="off"
                      />
                      <label class="form-check-label" for="showMarkers">
                        Show markers
                      </label>
                    </div>
                  </div>
                </div>
                <div class="row">
                  <!-- Pick map -->
                  <div class="col">
                    <div class="form-check">
                      <input
                        class="form-check-input"
                        type="checkbox"
                        id="pickMap"
                        autocomplete="off"
                      />
                      <label class="form-check-label" for="pickMap">
                        Pick only map
                      </label>
                    </div>
                  </div>
                  <!-- Pick point cloud -->
                  <div class="col">
                    <div class="form-check">
                      <input
                        class="form-check-input"
                        type="checkbox"
                        id="pickPointCloud"
                        autocomplete="off"
                      />
                      <label class="form-check-label" for="pickPointCloud">
                        Pick only point cloud
                      </label>
                    </div>
                  </div>
                </div>
              </form>
            </li>
            <li class="list-group-item">
              <span id="latency">Pick latency: 12.1 ms</span>
            </li>
            <li class="list-group-item">
              <div id="emptyWarning" class="p-4">
                <span class="fs-4 text-secondary">No result to display</span>
              </div>
              <!-- Result table -->
              <table id="table" class="table" style="display: none">
                <thead>
                  <tr>
                    <th scope="col">#</th>
                    <th scope="col">Entity</th>
                    <th scope="col">Object</th>
                    <th scope="col">X</th>
                    <th scope="col">Y</th>
                    <th scope="col">Z</th>
                  </tr>
                </thead>
                <tbody id="results">
                  <tr>
                    <td>?</td>
                    <td>?</td>
                    <td>?</td>
                    <td>?</td>
                    <td>?</td>
                    <td>?</td>
                  </tr>
                </tbody>
              </table>
            </li>
          </ul>
        </div>
      </div>
    </div>

    <script type="module" src="index.js"></script>
    <script>
      /* activate popovers */
      const popoverTriggerList = [].slice.call(
        document.querySelectorAll('[data-bs-toggle="popover"]'),
      );
      popoverTriggerList.map(
        // bootstrap is used as script in the template, disable warning about undef
        // eslint-disable-next-line no-undef
        (popoverTriggerEl) =>
          new bootstrap.Popover(popoverTriggerEl, {
            trigger: "hover",
            placement: "left",
            content: document.getElementById(
              popoverTriggerEl.getAttribute("data-bs-content"),
            ).innerHTML,
            html: true,
          }),
      );
    </script>
  </body>
</html>
package.json
{
    "name": "picking",
    "dependencies": {
        "@giro3d/giro3d": "0.40.0"
    },
    "devDependencies": {
        "vite": "^3.2.3"
    },
    "scripts": {
        "start": "vite",
        "build": "vite build"
    }
}