Extrude polygons for 3D indoor mapping.
Create a 3D indoor map with the fill-extrude-height paint property.
<!DOCTYPE html>
    <meta charset='utf-8' />
    <meta name='viewport' content='initial-scale=1,maximum-scale=1,user-scalable=no' />
    <script src='https://api.tiles.mapbox.com/mapbox-gl-js/v0.39.1/mapbox-gl.js'></script>
    <link href='https://api.tiles.mapbox.com/mapbox-gl-js/v0.39.1/mapbox-gl.css' rel='stylesheet' />
        body { margin:0; padding:0; }
        #map { position:absolute; top:0; bottom:0; width:100%; }

<div id='map'>
mapboxgl.accessToken = '<your access token here>';
var map = new mapboxgl.Map({
    container: 'map',
    style: 'mapbox://styles/mapbox/streets-v9',
    center: [-87.61694, 41.86625],
    zoom: 15.99,
    pitch: 40,
    bearing: 20

map.on('load', function() {

        'id': 'room-extrusion',
        'type': 'fill-extrusion',
        'source': {
            // Geojson Data source used in vector tiles, documented at
            // https://gist.github.com/ryanbaumann/a7d970386ce59d11c16278b90dde094d
            'type': 'geojson',
            'data': 'https://www.mapbox.com/mapbox-gl-js/assets/data/indoor-3d-map.geojson'
        'paint': {
            // See the Mapbox Style Spec for details on property functions
            // https://www.mapbox.com/mapbox-gl-style-spec/#types-function
            'fill-extrusion-color': {
                // Get the fill-extrusion-color from the source 'color' property.
                'property': 'color',
                'type': 'identity'
            'fill-extrusion-height': {
                // Get fill-extrusion-height from the source 'height' property.
                'property': 'height',
                'type': 'identity'
            'fill-extrusion-base': {
                // Get fill-extrusion-base from the source 'base_height' property.
                'property': 'base_height',
                'type': 'identity'
            // Make extrusions slightly opaque for see through indoor walls.
            'fill-extrusion-opacity': 0.5

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