// # Giro3D - Getting started// ### Welcome to Giro3D !// In this tutorial, we will cover the base features of Giro3D : the creation of the// [instance](../apidoc/classes/core.Instance.html), the creation of a// [map](../apidoc/classes/entities.Map.html), and setting up the navigation controls.// ##### Note// This walkthrough is based on the [2.5D Map example](../examples/getting-started.html).// Feel free to visit this example to see the final result of this tutorial.import { Vector3 } from "three";import { MapControls } from "three/examples/jsm/controls/MapControls.js";import TileWMS from "ol/source/TileWMS.js";import Instance from "@giro3d/giro3d/core/Instance.js";import Extent from "@giro3d/giro3d/core/geographic/Extent.js";import Map from "@giro3d/giro3d/entities/Map.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 Inspector from "@giro3d/giro3d/gui/Inspector.js";import TiledImageSource from "@giro3d/giro3d/sources/TiledImageSource.js";// ### Initialization of the Giro3D instance// Before creating our map, we must setup Giro3D in our page, by creating an instance.// The instance is the entry point of a Giro3D context. It needs a DOM element to render its scene.// #### Register the custom CRS// Our map uses the [EPSG:3946](https://epsg.io/3946) French coordinate reference system (CRS) that// is not built-in into Giro3D's CRS registry.// ####// Let's register a definition for this CRS. The definition is taken from https://epsg.io/3946.proj4.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",);// Now we are ready to create our instance. Note that the `crs` parameter is necessary to determine// the interpretation of coordinates from the 3D scene.// We will use the `view` element from our HTML page to initialize the instance.const instance = new Instance({ target: "view", crs: "EPSG:3946",});// ### Create the Map// Let's create a map of the city of [Lyon](https://en.wikipedia.org/wiki/Lyon), with satellite// imagery and a digital elevation model (DEM).// #### Specify the map extent// A map is a rectangular region of the world that will contain geographic data.// Let's define a geographic extent (or bounding box) of our map.// We initialize the [`Extent`](../apidoc/classes/core.geographic.Extent.html) class,// specifying the CRS name (that we just defined above), with the minimum and maximum X (longitude,// or easting) and Y (latitude, or northing) values.const xmin = 1837816.94334;const xmax = 1847692.32501;const ymin = 5170036.4587;const ymax = 5178412.82698;const extent = new Extent("EPSG:3946", xmin, xmax, ymin, ymax);// #### Create the Map object// Now we can create the Map. The only mandatory parameter is the extent// but you can experiment with the other options if you'd like.const map = new Map({ extent });// Let's add the map to the instance.instance.add(map);// #### Create the color layer// If we looked at the page now, the map would be rendered as a colored rectangle.// This is the aspect of the map without any data in it (only the background color).// Nothing very exciting.// Let's add a color layer.// In Giro3D, layers are the basic components of the Map. They can be either a color layer,// or an elevation layer. In both cases, the data comes from a source.// ##### Specify the data source// Let's create a source that will pull data from a WMS service.// We are using the// [`TiledImageSource`](../apidoc/classes/sources.TiledImageSource.html) for that.// This source will wrap an OpenLayers source, in this case a `TileWMS`.const satelliteSource = new TiledImageSource({ source: new TileWMS({ url: "https://data.geopf.fr/wms-r", projection: "EPSG:3946", params: { LAYERS: ["ORTHOIMAGERY.ORTHOPHOTOS"], FORMAT: "image/jpeg", }, }),});// ##### Create the layer// Now we can create the layer. Note that we specify an extent for the layer. This is not// strictly required, but since our map is much smaller than the WMS source, we want to avoid// processing data that is outside our layer.const colorLayer = new ColorLayer({ name: "satellite", source: satelliteSource, extent: map.extent,});// And add it to the map.map.addLayer(colorLayer);// Note: `addLayer()` is an asynchronous method, because the layer must be prepared before being// ready for rendering. We could use the returned promise to wait for the end of the preprocessing// step, but we don't need that in our example.// #### Creation of the elevation layer// Creating an elevation layer is a very similar process to the color layer : we initialize the// source, then create the layer and add it to the map.// The only difference is that we are going to use an// [`ElevationLayer`](../apidoc/classes/core.layer.ElevationLayer.html).// Contrary to the color layer, the elevation layer does not produce any color information on the// map, but it rather deforms the map to display the terrain (hence the name 2.5D map).// Let's create a WMS source for this layer.const demSource = new TiledImageSource({ source: new TileWMS({ url: "https://data.geopf.fr/wms-r", projection: "EPSG:3946", crossOrigin: "anonymous", params: { LAYERS: ["ELEVATION.ELEVATIONGRIDCOVERAGE.HIGHRES"], FORMAT: "image/x-bil;bits=32", }, }), format: new BilFormat(), noDataValue: -1000,});// Then create the elevation layer.const elevationLayer = new ElevationLayer({ name: "dem", extent: map.extent, source: demSource,});// ##### Add the layer// Now we are ready to add our layer to the map.map.addLayer(elevationLayer);// ### Set the camera and navigation controls// Giro3D uses the THREE.js controls to navigate in the scene. In our example, we are going to use// the `MapControls`, which are perfectly adapted to our need.// Let's get the THREE camera of our scene.const camera = instance.view.camera;// Let's specify the camera position. We will position it in the southwest corner of the map, at an// altitude of 2000 meters.const cameraAltitude = 2000;const cameraPosition = new Vector3(extent.west, extent.south, cameraAltitude);camera.position.copy(cameraPosition);// Now we can create the `MapControls` with our camera and the DOM element of our scene.const controls = new MapControls(camera, instance.domElement);// Let's set the controls' target to our map center.controls.target = extent.centerAsVector3();// And specify some parameters for the navigation.controls.enableDamping = true;controls.dampingFactor = 0.2;controls.maxPolarAngle = Math.PI / 2.3;controls.saveState();// Now let's register those controls with the instance. The instance will automatically register// the event handlers relevant to the navigation in the scene.instance.view.setControls(controls);// ### Optional: Set up the inspector// This is an optional step, but very useful for diagnostic and debugging issues with Giro3D.// The `Inspector` is a panel containing lots of useful information about the Giro3D instance.// This supposes that we have a `div` ready to host our inspector.Inspector.attach("inspector", instance);// ### The StatusBar// This widget is no part of the Giro3D library, but is used in the examples// to display various informations about the scene, such as the geographic// coordinates of the mouse cursor.// Let's initialize the coordinate bar widget on our instance.// ### Moving around// Use the mouse the navigate in the scene and observe the map updating with fresh data.// [See the final result](../examples/getting-started.html).