This example creates a ten-pixel-wide blue polyline with a 75% opacity that shows an arbitrary route through downtown San Francisco.
<!DOCTYPE html>
<html>
<head>
<title>Photorealistic 3D Maps in Maps JavaScript Polyline Demo</title>
<style>
html,
body {
height:100%;
margin: 0;
padding: 0;
}
gmp-map-3d {
height: 400px;
}
</style>
</head>
<body>
<gmp-map-3d mode="hybrid" heading="25" range="2500" tilt="45" center="37.7905,-122.3989,165">
<gmp-polyline-3d altitude-mode="relative-to-ground" stroke-color="rgba(25, 102, 210, 0.75)" stroke-width="10"></gmp-polyline-3d>
</gmp-map-3d>
<script>
(g=>{var h,a,k,p="The Google Maps JavaScript API",c="google",l="importLibrary",q="__ib__",m=document,b=window;b=b[c]||(b[c]={});var d=b.maps||(b.maps={}),r=new Set,e=new URLSearchParams,u=()=>h||(h=new Promise(async(f,n)=>{await (a=m.createElement("script"));e.set("libraries",[...r]+"");for(k in g)e.set(k.replace(/[A-Z]/g,t=>"_"+t[0].toLowerCase()),g[k]);e.set("callback",c+".maps."+q);a.src=`https://maps.${c}apis.com/maps/api/js?`+e;d[q]=f;a.onerror=()=>h=n(Error(p+" could not load."));a.nonce=m.querySelector("script[nonce]")?.nonce||"";m.head.append(a)}));d[l]?console.warn(p+" only loads once. Ignoring:",g):d[l]=(f,...n)=>r.add(f)&&u().then(()=>d[l](f,...n))})({
key: "<YOUR_API_KEY>",
v: "alpha"
});
</script>
<script>
const polyline = document.querySelector('gmp-polyline-3d');
async function init() {
// Import the needed libraries.
await google.maps.importLibrary('maps3d');
polyline.coordinates = [
{lat: 37.80515638571346, lng: -122.4032569467164},
{lat: 37.80337073509504, lng: -122.4012878349353},
{lat: 37.79925208843463, lng: -122.3976697250461},
{lat: 37.7989102378512, lng: -122.3983408725656},
{lat: 37.79887832784348, lng: -122.3987094864192},
{lat: 37.79786443410338, lng: -122.4066878788802},
{lat: 37.79549248916587, lng: -122.4032992702785},
{lat: 37.78861484290265, lng: -122.4019489189814},
{lat: 37.78618687561075, lng: -122.398969592545},
{lat: 37.7892310309145, lng: -122.3951458683092},
{lat: 37.7916358762409, lng: -122.3981969390652}
];
}
init();
</script>
</body>
</html>