Change building color based on zoom level | UNL Map JS Docs

Use the interpolate expression to ease-in the building layer and smoothly fade from one color to the next.

Note

If you want to test this example, edit it in JSFiddle or CodePen and replace the "YOUR-OWN-API-KEY" and "YOUR-OWN-VPM-ID" placeholders with your actual api key and vpm id.

<!DOCTYPE html>
<html>
<head>
<meta charset="utf-8" />
<title>Change building color based on zoom level</title>
<meta name="viewport" content="initial-scale=1,maximum-scale=1,user-scalable=no" />
<script src="https://unpkg.com/unl-map-js@0.1.5/lib/unl-map-js.js"></script>
<link href="https://unpkg.com/unl-map-js@0.1.5/lib/unl-map-js.css" rel="stylesheet" />
<link
href="https://unpkg.com/maplibre-gl@2.1.9/dist/maplibre-gl.css"
rel="stylesheet"
/>
<style>
	body { margin: 0; padding: 0; }
	#map { position: absolute; top: 0; bottom: 0; width: 100%; }
</style>
</head>
<body>
<style>
#zoom {
display: block;
position: relative;
margin: 20px auto;
width: 50%;
height: 40px;
padding: 10px;
border: none;
border-radius: 3px;
font-size: 12px;
text-align: center;
color: #fff;
background: #ee8a65;
}
</style>
<div id="map"></div>
<button id="zoom">Zoom to buildings</button>
<script>
var map = new UnlSdk.Map({
container: "map",
apiKey: "YOUR-OWN-API-KEY",
vpmId: "YOUR-OWN-VPM-ID",
center: [-73.935242, 40.73061],
zoom: 13,
});
 
map.on("load", function () {
map.setPaintProperty("building_level15", "fill-extrusion-color", [
"interpolate",
["exponential", 0.5],
["zoom"],
15,
"#e2714b",
22,
"#eee695",
]);
 
map.setPaintProperty("building_level15", "fill-extrusion-opacity", [
"interpolate",
["exponential", 0.5],
["zoom"],
15,
0,
22,
1,
]);
});
 
document.getElementById("zoom").addEventListener("click", function () {
map.zoomTo(19, { duration: 9000 });
});
</script>
 
</body>
</html>