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Add a 3D model with three.js

Use a custom style layer with three.js to add a 3D model to the map.

<!DOCTYPE html>
<html lang="en">
<head>
    <title>Add a 3D model with three.js</title>
    <meta property="og:description" content="Use a custom style layer with three.js to add a 3D model to the map." />
    <meta charset='utf-8'>
    <meta name="viewport" content="width=device-width, initial-scale=1">
    <link rel='stylesheet' href='https://unpkg.com/maplibre-gl@4.4.0/dist/maplibre-gl.css' />
    <script src='https://unpkg.com/maplibre-gl@4.4.0/dist/maplibre-gl.js'></script>
    <style>
        body { margin: 0; padding: 0; }
        html, body, #map { height: 100%; }
    </style>
</head>
<body>
<script src="https://unpkg.com/three@0.147.0/build/three.min.js"></script>
<script src="https://unpkg.com/three@0.147.0/examples/js/loaders/GLTFLoader.js"></script>
<div id="map"></div>
<script>
    const map = (window.map = new maplibregl.Map({
        container: 'map',
        style:
            'https://api.maptiler.com/maps/basic/style.json?key=get_your_own_OpIi9ZULNHzrESv6T2vL',
        zoom: 18,
        center: [148.9819, -35.3981],
        pitch: 60,
        antialias: true // create the gl context with MSAA antialiasing, so custom layers are antialiased
    }));

    // parameters to ensure the model is georeferenced correctly on the map
    const modelOrigin = [148.9819, -35.39847];
    const modelAltitude = 0;
    const modelRotate = [Math.PI / 2, 0, 0];

    const modelAsMercatorCoordinate = maplibregl.MercatorCoordinate.fromLngLat(
        modelOrigin,
        modelAltitude
    );

    // transformation parameters to position, rotate and scale the 3D model onto the map
    const modelTransform = {
        translateX: modelAsMercatorCoordinate.x,
        translateY: modelAsMercatorCoordinate.y,
        translateZ: modelAsMercatorCoordinate.z,
        rotateX: modelRotate[0],
        rotateY: modelRotate[1],
        rotateZ: modelRotate[2],
        /* Since our 3D model is in real world meters, a scale transform needs to be
        * applied since the CustomLayerInterface expects units in MercatorCoordinates.
        */
        scale: modelAsMercatorCoordinate.meterInMercatorCoordinateUnits()
    };

    const THREE = window.THREE;

    // configuration of the custom layer for a 3D model per the CustomLayerInterface
    const customLayer = {
        id: '3d-model',
        type: 'custom',
        renderingMode: '3d',
        onAdd (map, gl) {
            this.camera = new THREE.Camera();
            this.scene = new THREE.Scene();

            // create two three.js lights to illuminate the model
            const directionalLight = new THREE.DirectionalLight(0xffffff);
            directionalLight.position.set(0, -70, 100).normalize();
            this.scene.add(directionalLight);

            const directionalLight2 = new THREE.DirectionalLight(0xffffff);
            directionalLight2.position.set(0, 70, 100).normalize();
            this.scene.add(directionalLight2);

            // use the three.js GLTF loader to add the 3D model to the three.js scene
            const loader = new THREE.GLTFLoader();
            loader.load(
                'https://maplibre.org/maplibre-gl-js/docs/assets/34M_17/34M_17.gltf',
                (gltf) => {
                    this.scene.add(gltf.scene);
                }
            );
            this.map = map;

            // use the MapLibre GL JS map canvas for three.js
            this.renderer = new THREE.WebGLRenderer({
                canvas: map.getCanvas(),
                context: gl,
                antialias: true
            });

            this.renderer.autoClear = false;
        },
        render (gl, matrix) {
            const rotationX = new THREE.Matrix4().makeRotationAxis(
                new THREE.Vector3(1, 0, 0),
                modelTransform.rotateX
            );
            const rotationY = new THREE.Matrix4().makeRotationAxis(
                new THREE.Vector3(0, 1, 0),
                modelTransform.rotateY
            );
            const rotationZ = new THREE.Matrix4().makeRotationAxis(
                new THREE.Vector3(0, 0, 1),
                modelTransform.rotateZ
            );

            const m = new THREE.Matrix4().fromArray(matrix);
            const l = new THREE.Matrix4()
                .makeTranslation(
                    modelTransform.translateX,
                    modelTransform.translateY,
                    modelTransform.translateZ
                )
                .scale(
                    new THREE.Vector3(
                        modelTransform.scale,
                        -modelTransform.scale,
                        modelTransform.scale
                    )
                )
                .multiply(rotationX)
                .multiply(rotationY)
                .multiply(rotationZ);

            this.camera.projectionMatrix = m.multiply(l);
            this.renderer.resetState();
            this.renderer.render(this.scene, this.camera);
            this.map.triggerRepaint();
        }
    };

    map.on('style.load', () => {
        map.addLayer(customLayer);
    });
</script>
</body>
</html>