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 as THREEMath, 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 Coordinates from '@giro3d/giro3d/core/geographic/Coordinates.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';
import StatusBar from './widgets/StatusBar.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 viewerDiv = document.getElementById('viewerDiv');
const instance = new Instance(viewerDiv, { crs: extent.crs() });
const map = new Map('planar', { extent });
instance.add(map);
// Function to look at an extent from top
function lookTopDownAt(lookAtExtent, lookAtAltitude = 0) {
const hFov = THREEMath.degToRad(instance.camera.camera3D.fov) / 2;
const altitude = (
Math.max(
lookAtExtent.dimensions().x / instance.camera.camera3D.aspect,
lookAtExtent.dimensions().y,
) / Math.tan(hFov)) * 0.5;
const position = lookAtExtent.center().xyz().add(new Vector3(0, 0, altitude));
const lookAt = lookAtExtent.center().xyz();
lookAt.z = lookAtAltitude;
// place camera above
instance.camera.camera3D.position.copy(position);
// look down
instance.camera.camera3D.lookAt(lookAt);
// make sure the camera isn't rotating around its view axis
instance.camera.camera3D.rotation.z = 0;
instance.camera.camera3D.rotation.x = 0.01; // quickfix to avoid bizarre jumps
instance.controls.target.copy(lookAt);
instance.controls.saveState();
instance.notifyChange(instance.camera.camera3D);
}
const wmsSource = new TiledImageSource({
source: new TileWMS({
url: 'https://wxs.ign.fr/ortho/geoportail/r/wms',
projection: 'EPSG:3946',
params: {
LAYERS: ['HR.ORTHOIMAGERY.ORTHOPHOTOS'],
FORMAT: 'image/jpeg',
},
}),
});
const colorLayer = new ColorLayer(
'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({
format: new GeoJSON(),
data: 'https://raw.githubusercontent.com/iTowns/iTowns2-sample-data/master/lyon.geojson',
style,
});
const geoJsonLayer = new ColorLayer(
'geo', {
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 = `${feature.get('numero_arrondissement')}e arrondissement`;
// Any CSS style is supported
text.style.color = '#ffffff';
text.style.padding = '0.2em 1em';
text.style.maxWidth = '200px';
text.style.border = '2px solid #cccccc';
text.style.backgroundColor = '#080808';
text.style.textAlign = 'center';
text.style.opacity = 0.8;
// Adding the label requires a Vector3 position, let's compute that
// We'll position the label at the center of the geometry extent
const olExtent = feature.getGeometry().getExtent();
const giro3dExtent = new Extent('EPSG:3946', olExtent[0], olExtent[2], olExtent[1], olExtent[3]);
if (!giro3dExtent.isInside(extent)) {
// The extent of the feature is not fully inside the map extent,
// let's crop it to make sure the label will be inside the map
giro3dExtent.intersect(extent);
}
const position = new Vector2();
giro3dExtent.center(position);
// Create our label and position it
const label = new CSS2DObject(text);
label.position.set(position.x, position.y, 0);
label.updateMatrixWorld();
// Give it a name so it shows up nicely in the inspector
label.name = `${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._over = true;
});
text.addEventListener('mouseout', () => {
text._over = false;
});
text.addEventListener('click', () => {
if (text._over) lookTopDownAt(giro3dExtent);
});
}
instance.notifyChange(geoJsonLayer);
});
const cameraPosition = new Coordinates(
'EPSG:3946',
extent.west(), extent.south(), 2000,
).xyz();
instance.camera.camera3D.position.copy(cameraPosition);
const controls = new MapControls(instance.camera.camera3D, instance.domElement);
controls.target = extent.center().xyz();
controls.saveState();
controls.enableDamping = true;
controls.dampingFactor = 0.2;
controls.maxPolarAngle = Math.PI / 2.3;
instance.useTHREEControls(controls);
Inspector.attach(document.getElementById('panelDiv'), instance);
StatusBar.bind(instance);