Create a advanced heatmap layer
This code example demonstrates how to create a heatmap layer on a 3D globe with integrated terrain elevation data.
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset='utf-8'>
<meta name="viewport" content="width=device-width, initial-scale=1">
<script src="https://cdn.smartmaps.cloud/packages/smartmaps/smartmaps-gl/v2/umd/smartmaps-gl.min.js"></script>
<style>
body {
margin: 0;
padding: 0;
}
html,
body,
#map {
height: 100%;
}
</style>
</head>
<body>
<div id="map"></div>
<script>
const map = new smartmapsgl.Map({
apiKey: "INSERT API-KEY",
container: 'map',
maxPitch: 50,
center: [-120, 37.422],
zoom: 7,
style: smartmapsgl.MapStyle.AUTO,
terrain: {
activated: true,
}
});
map.addControl(
new smartmapsgl.NavigationControl({
visualizePitch: true,
showZoom: true,
showCompass: true
})
);
map.addControl(
new smartmapsgl.GlobeControl()
);
map.on('load', () => {
// Add a geojson point source.
// Heatmap layers also work with a vector tile source.
map.addSource("earthquakes", {
type: "geojson",
data: "../data/earthquakes.geojson",
});
map.addLayer(
{
'id': 'earthquakes-heat',
'type': 'heatmap',
'source': 'earthquakes',
'maxzoom': 9,
'paint': {
// Increase the heatmap weight based on frequency and property magnitude
'heatmap-weight': [
'interpolate',
['linear'],
['get', 'mag'],
0,
0,
6,
1
],
// Increase the heatmap color weight weight by zoom level
// heatmap-intensity is a multiplier on top of heatmap-weight
'heatmap-intensity': [
'interpolate',
['linear'],
['zoom'],
0,
1,
9,
3
],
// Color ramp for heatmap. Domain is 0 (low) to 1 (high).
// Begin color ramp at 0-stop with a 0-transparency color
// to create a blur-like effect.
'heatmap-color': [
'interpolate',
['linear'],
['heatmap-density'],
0,
'rgba(33,102,172,0)',
0.2,
'rgb(103,169,207)',
0.4,
'rgb(209,229,240)',
0.6,
'rgb(253,219,199)',
0.8,
'rgb(239,138,98)',
1,
'rgb(178,24,43)'
],
// Adjust the heatmap radius by zoom level
'heatmap-radius': [
'interpolate',
['linear'],
['zoom'],
0,
2,
9,
20
],
// Transition from heatmap to circle layer by zoom level
'heatmap-opacity': [
'interpolate',
['linear'],
['zoom'],
7,
1,
9,
0
]
}
}
);
map.addLayer(
{
'id': 'earthquakes-point',
'type': 'circle',
'source': 'earthquakes',
'minzoom': 7,
'paint': {
// Size circle radius by earthquake magnitude and zoom level
'circle-radius': [
'interpolate',
['linear'],
['zoom'],
7,
['interpolate', ['linear'], ['get', 'mag'], 1, 1, 6, 4],
16,
['interpolate', ['linear'], ['get', 'mag'], 1, 5, 6, 50]
],
'circle-color': [
'interpolate',
['linear'],
['get', 'mag'],
1,
'rgba(33,102,172,0)',
2,
'rgb(103,169,207)',
3,
'rgb(209,229,240)',
4,
'rgb(253,219,199)',
5,
'rgb(239,138,98)',
6,
'rgb(178,24,43)'
],
'circle-stroke-color': 'white',
'circle-stroke-width': 1,
// Transition from heatmap to circle layer by zoom level
'circle-opacity': [
'interpolate',
['linear'],
['zoom'],
7,
0,
8,
1
]
}
}
);
});
</script>
</body>
</html>