Use the Atmosphere entity to display a realistic atmosphere for a specific ellipsoid. The external side of the sphere displays the atmospheric halo, and the internal side displays a sky dome with realistic atmospheric scattering.
index.js
import { Clock, Color, DirectionalLight, Mesh, MeshBasicMaterial, MeshStandardMaterial, SphereGeometry, Vector3,} from "three";import { CSS2DObject } from "three/examples/jsm/renderers/CSS2DRenderer.js";import { OrbitControls } from "three/examples/jsm/controls/OrbitControls.js";import Coordinates from "@giro3d/giro3d/core/geographic/Coordinates";import Ellipsoid from "@giro3d/giro3d/core/geographic/Ellipsoid";import Instance from "@giro3d/giro3d/core/Instance.js";import Atmosphere from "@giro3d/giro3d/entities/Atmosphere";import Inspector from "@giro3d/giro3d/gui/Inspector";import DrawTool from "@giro3d/giro3d/interactions/DrawTool";import SkyDome from "@giro3d/giro3d/entities/SkyDome";import EllipsoidHelper from "@giro3d/giro3d/helpers/EllipsoidHelper";import { bindButton } from "./widgets/bindButton";import { bindColorPicker } from "./widgets/bindColorPicker";import { bindSlider } from "./widgets/bindSlider";import { bindToggle } from "./widgets/bindToggle";const Z_UP = new Vector3(0, 0, 1);const instance = new Instance({ target: "view", crs: "EPSG:4978", backgroundColor: "black",});const ellipsoid = Ellipsoid.WGS84;const DEFAULT_PARAMS = { automaticSunRotation: true, fov: 30, redWavelength: 0.65, greenWavelength: 0.57, blueWavelength: 0.475, thickness: 300_000, globeColor: "#1e4485", showSunObject: true, sunPosition: new Vector3(0.2, 1, 0), inner: true, lookAtSun: false, outer: true, showSunMarker: false, showEllipsoidHelper: false, observer: new Coordinates("EPSG:4326", 40, 25, 36_000_000), target: new Coordinates("EPSG:4326", 0, 0, 0),};let params = { ...DEFAULT_PARAMS };// For this example, we create a simple sphere Mesh. For a full-featured globe with map/GIS support, create a Globe object (see the "globe" example)const globe = new Mesh( new SphereGeometry(ellipsoid.semiMajorAxis, 256, 128), new MeshStandardMaterial({ color: params.globeColor, emissive: params.globeColor, emissiveIntensity: 0.1, }),);globe.name = "Globe";// Scale it to match the ellipsoid compression factor.globe.scale.set(1, 1, ellipsoid.compressionFactor);globe.updateMatrixWorld(true);instance.threeObjects.add(globe);let atmosphere;// The skydome will be visible when the camera is near the ground.const skyDome = new SkyDome();instance.add(skyDome);// Create simple orbit controls to move around globe.// Those controls will be disabled when we are on the ground.const controls = new OrbitControls(instance.view.camera, instance.domElement);controls.target.set(0, 0, 0);instance.view.setControls(controls);function createAtmosphere() { if (atmosphere) { instance.remove(atmosphere); } atmosphere = new Atmosphere({ ellipsoid, thickness: params.thickness }); instance.add(atmosphere); if (params.redWavelength) { atmosphere.redWavelength = params.redWavelength; atmosphere.greenWavelength = params.greenWavelength; atmosphere.blueWavelength = params.blueWavelength; } atmosphere.inner.visible = params.inner; atmosphere.outer.visible = params.outer; atmosphere.setSunPosition(params.sunPosition); skyDome.setSunPosition(params.sunPosition); instance.notifyChange(atmosphere);}createAtmosphere();const camera = instance.view.camera;function updateCamera() { const { observer, target } = params; const position = ellipsoid.toCartesian( observer.latitude, observer.longitude, observer.altitude, ); camera.position.set(position.x, position.y, position.z); if (observer.altitude < 1_000_000) { const up = ellipsoid.getNormal(observer.latitude, observer.longitude); camera.up = up; } else { camera.up = Z_UP; } const lookAt = ellipsoid.toCartesian( target.latitude, target.longitude, target.altitude, ); camera.lookAt(lookAt); camera.fov = params.fov; camera.updateMatrixWorld(true);}updateCamera();const sun = new Mesh( new SphereGeometry(ellipsoid.semiMajorAxis * 0.02), new MeshBasicMaterial({ color: "yellow" }),);const elt = document.createElement("span");elt.style.width = "15px";elt.style.height = "15px";elt.style.backgroundColor = "cyan";elt.style.display = "inline-block";elt.style.borderRadius = "50%";elt.style.borderWidth = "2px";elt.style.borderStyle = "solid";elt.style.borderColor = "black";const sunCSSMarker = new CSS2DObject(elt);sun.add(sunCSSMarker);sun.name = "Sun";instance.add(sun);// Let's create an ellipsoid helper to help us visualize the ellipsoid and its axes.const helper = new EllipsoidHelper({ ellipsoid: ellipsoid.scale(1.01), segments: 64,});instance.threeObjects.add(helper);helper.visible = params.showEllipsoidHelper;const sunlight = new DirectionalLight();instance.add(sunlight);instance.add(sunlight.target);const apparentSunCourseRadius = ellipsoid.semiMajorAxis * 2;const actualSunCourseRAdius = ellipsoid.semiMajorAxis * 200;const clock = new Clock();let time = 0;const actualSunPosition = new Vector3(0, 0, 0);const updateSunPosition = () => { requestAnimationFrame(updateSunPosition); if (!params.automaticSunRotation) { clock.stop(); return; } if (!clock.running) { clock.start(); } const speed = -1; time += clock.getDelta(); const t = speed * time; const cosT = Math.cos(t); const sinT = Math.sin(t); const x = cosT * apparentSunCourseRadius; const y = sinT * apparentSunCourseRadius; actualSunPosition.setX(cosT * actualSunCourseRAdius); actualSunPosition.setY(sinT * actualSunCourseRAdius); sun.position.set(x, y, 0); sun.material.visible = params.showSunObject; sun.updateMatrixWorld(true); sunlight.position.copy(sun.position); sunlight.lookAt(globe.position); sunlight.updateMatrixWorld(true); if (atmosphere) { atmosphere.setSunPosition(sun.position); } skyDome.setSunPosition(sun.position); if (params.lookAtSun) { camera.lookAt(actualSunPosition); } instance.notifyChange();};updateSunPosition();const [setRed] = bindSlider("red", (v) => { params.redWavelength = v; atmosphere.redWavelength = v; instance.notifyChange(atmosphere);});const [setGreen] = bindSlider("green", (v) => { params.greenWavelength = v; atmosphere.greenWavelength = v; instance.notifyChange(atmosphere);});const [setBlue] = bindSlider("blue", (v) => { params.blueWavelength = v; atmosphere.blueWavelength = v; instance.notifyChange(atmosphere);});const [setGlobeColor] = bindColorPicker("globe-color", (c) => { const color = new Color(c); params.globeColor = "#" + color.getHexString(); globe.material.color = color; globe.material.emissive = color; instance.notifyChange();});const [setThickness] = bindSlider("thickness", (thickness) => { params.thickness = thickness; createAtmosphere();});const [showInner] = bindToggle("inner", (show) => { params.inner = show; atmosphere.inner.visible = show; instance.notifyChange();});const [showHelper] = bindToggle("show-ellipsoid", (show) => { params.showEllipsoidHelper = show; helper.showLabels = show; helper.visible = show; instance.notifyChange();});const [setLookAtSun] = bindToggle("look-at-sun", (enable) => { params.lookAtSun = enable; instance.notifyChange();});const [setAutomaticSunRotation] = bindToggle( "automatic-sun-rotation", (enabled) => { params.automaticSunRotation = enabled; },);const [showOuter] = bindToggle("outer", (show) => { params.outer = show; atmosphere.outer.visible = show; instance.notifyChange();});const [showMarker] = bindToggle("sun-marker", (show) => { params.showSunMarker = show; sunCSSMarker.visible = show; instance.notifyChange();});function goToGround(latitude, longitude) { params.fov = 120; helper.showLabels = false; controls.enabled = false; instance.view.setControls(null); const altitude = 100; params.observer = new Coordinates("EPSG:4326", longitude, latitude, altitude); params.showSunObject = false; params.lookAtSun = false; params.target = new Coordinates( params.observer.crs, longitude + 0.01, // Look toward the east (the sunrise) latitude, altitude + 200, // And slightly above the horizon ); setLookAtSun(params.lookAtSun); showInner(false); showOuter(false); updateCamera();}bindButton("set-ground-position", () => { const drawTool = new DrawTool({ instance }); function vertexLabelFormatter({ position }) { const geo = ellipsoid.toGeodetic(position.x, position.y, position.z); return `lat: ${geo.latitude.toFixed(3)}°, lon: ${geo.longitude.toFixed(3)}°`; } drawTool .createPoint({ showVertexLabels: true, vertexLabelFormatter }) .then((shape) => { instance.remove(shape); const point = shape.points[0]; const { latitude, longitude } = ellipsoid.toGeodetic( point.x, point.y, point.z, ); goToGround(latitude, longitude); });});function reset() { params = { ...DEFAULT_PARAMS, observer: DEFAULT_PARAMS.observer.clone(), target: DEFAULT_PARAMS.target.clone(), }; showHelper(params.showEllipsoidHelper); setRed(params.redWavelength); setGreen(params.greenWavelength); setBlue(params.blueWavelength); setGlobeColor(params.globeColor); setThickness(params.thickness, 3_000, 300_000, 1); showOuter(params.outer); showInner(params.inner); setLookAtSun(params.lookAtSun); showMarker(params.showSunMarker); setAutomaticSunRotation(params.automaticSunRotation); updateCamera(); instance.view.setControls(controls); controls.enabled = true; controls.target.set(0, 0, 0);}bindButton("reset", reset);reset();Inspector.attach("inspector", instance);