Display HTML labels in the 3D scene.
Labels are HTML elements produced by Three.js' CSS2DRenderer
. They can be styled using normal CSS styling.
import { GeoJSON } from "ol/format.js";
import { Fill, Stroke, Style } from "ol/style.js";
import TileWMS from "ol/source/TileWMS.js";
import { MathUtils, Vector2, Vector3 } from "three";
import { MapControls } from "three/examples/jsm/controls/MapControls.js";
import { CSS2DObject } from "three/examples/jsm/renderers/CSS2DRenderer.js";
import Extent from "@giro3d/giro3d/core/geographic/Extent.js";
import Instance from "@giro3d/giro3d/core/Instance.js";
import ColorLayer from "@giro3d/giro3d/core/layer/ColorLayer.js";
import Map from "@giro3d/giro3d/entities/Map.js";
import Inspector from "@giro3d/giro3d/gui/Inspector.js";
import VectorSource from "@giro3d/giro3d/sources/VectorSource.js";
import TiledImageSource from "@giro3d/giro3d/sources/TiledImageSource.js";
// This example is based on planar_vector example, adding labels on features.
// You can directly jump to `geoJsonLayer.source.addEventListener('featuresloadend', ...)`,
// as the rest is similar.
Instance.registerCRS(
"EPSG:3946",
"+proj=lcc +lat_1=45.25 +lat_2=46.75 +lat_0=46 +lon_0=3 +x_0=1700000 +y_0=5200000 +ellps=GRS80 +towgs84=0,0,0,0,0,0,0 +units=m +no_defs",
);
const extent = new Extent(
"EPSG:3946",
1837816.94334,
1847692.32501,
5170036.4587,
5178412.82698,
);
const instance = new Instance({
target: "view",
crs: extent.crs,
});
const map = new Map({ extent });
instance.add(map);
const controls = new MapControls(instance.view.camera, instance.domElement);
controls.target = extent.centerAsVector3();
controls.saveState();
controls.enableDamping = true;
controls.dampingFactor = 0.2;
controls.maxPolarAngle = Math.PI / 2.3;
instance.view.setControls(controls);
// Function to look at an extent from top
function lookTopDownAt(lookAtExtent, lookAtAltitude = 0) {
const camera = instance.view.camera;
const fov = camera.fov;
const aspect = camera.aspect;
const hFov = MathUtils.degToRad(fov) / 2;
const dims = lookAtExtent.dimensions();
const altitude = (Math.max(dims.x / aspect, dims.y) / Math.tan(hFov)) * 0.5;
const position = lookAtExtent
.centerAsVector3()
.add(new Vector3(0, 0, altitude));
const lookAt = lookAtExtent.centerAsVector3();
lookAt.z = lookAtAltitude;
// place camera above
camera.position.copy(position);
// look down
camera.lookAt(lookAt);
// make sure the camera isn't rotating around its view axis
camera.rotation.z = 0;
camera.rotation.x = 0.01; // quickfix to avoid bizarre jumps
controls.target.copy(lookAt);
controls.saveState();
instance.notifyChange(camera);
}
const wmsSource = new TiledImageSource({
source: new TileWMS({
url: "https://data.geopf.fr/wms-r",
projection: "EPSG:3946",
params: {
LAYERS: ["HR.ORTHOIMAGERY.ORTHOPHOTOS"],
FORMAT: "image/jpeg",
},
}),
});
const colorLayer = new ColorLayer({
name: "wms_imagery",
extent,
source: wmsSource,
});
map.addLayer(colorLayer);
const style = new Style({
fill: new Fill({
color: "rgba(255, 165, 0, 0.2)",
}),
stroke: new Stroke({
color: "white",
width: 2,
}),
});
const geojsonSource = new VectorSource({
data: {
url: "https://raw.githubusercontent.com/iTowns/iTowns2-sample-data/master/lyon.geojson",
format: new GeoJSON(),
},
style,
});
const geoJsonLayer = new ColorLayer({
name: "geojson",
extent,
source: geojsonSource,
});
map.addLayer(geoJsonLayer).then(() => {
// Traverse the OpenLayers features that were added
for (const feature of geojsonSource.getFeatures()) {
// Create a label for each feature
const text = document.createElement("div");
// Virtually any inner markup is supported, here we're just inserting text
text.innerText = feature.get("nom");
text.title = `${feature.get("numero_arrondissement")}e arrondissement`;
// Any CSS style is supported
text.style.color = "#ffffff";
text.style.padding = "0.2em 1em";
text.style.maxWidth = "200px";
text.style.border = "2px solid #cccccc";
text.style.backgroundColor = "#080808";
text.style.textAlign = "center";
text.style.opacity = "80%";
// Adding the label requires a Vector3 position, let's compute that
// We'll position the label at the center of the geometry extent
const olExtent = feature.getGeometry().getExtent();
const giro3dExtent = new Extent(
"EPSG:3946",
olExtent[0],
olExtent[2],
olExtent[1],
olExtent[3],
);
if (!giro3dExtent.isInside(extent)) {
// The extent of the feature is not fully inside the map extent,
// let's crop it to make sure the label will be inside the map
giro3dExtent.intersect(extent);
}
const position = new Vector2();
giro3dExtent.centerAsVector2(position);
// Create our label and position it
const label = new CSS2DObject(text);
label.position.set(position.x, position.y, 0);
label.updateMatrixWorld();
// Give it a name so it shows up nicely in the inspector
label.name = `${feature.get("nom")}`;
// Simply add it to our instance
// (we could also create a dedicated THREE.Group to have all the labels inside)
instance.add(label);
// By default, labels don't have mouse interaction enabled (pointerEvents = 'none')
// Let's change that so we can click on it to zoom on it
text.style.cursor = "pointer";
text.style.pointerEvents = "auto";
// Controls can interfer with the click event
// e.g. this click event is triggered when we drag the map and the dragging ends on a label
// but the mouseover is not, so use that to know if the user really wants to click
// on the label.
text.addEventListener("mouseover", () => {
text.setAttribute("giro3d_over", "on");
});
text.addEventListener("mouseout", () => {
text.removeAttribute("giro3d_over");
});
text.addEventListener("click", () => {
if (text.getAttribute("giro3d_over")) {
lookTopDownAt(giro3dExtent);
}
});
}
instance.notifyChange(geoJsonLayer);
});
instance.view.camera.position.set(extent.west, extent.south, 2000);
Inspector.attach("inspector", instance);
<!doctype html>
<html lang="en">
<head>
<title>HTML labels</title>
<meta charset="UTF-8" />
<meta name="name" content="htmllabels" />
<meta name="description" content="Display HTML labels in the 3D scene." />
<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>
<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>
{
"name": "htmllabels",
"dependencies": {
"@giro3d/giro3d": "0.41.0"
},
"devDependencies": {
"vite": "^3.2.3"
},
"scripts": {
"start": "vite",
"build": "vite build"
}
}