circles = {
const step = 10;
const circle = d3.geoCircle().center(d => d).radius(step / 4).precision(10);
const coordinates = [];
for (let y = -80; y <= 80; y += step) {
for (let x = -180; x < 180; x += step) {
coordinates.push(circle([x, y]).coordinates);
}
}
return {type: "MultiPolygon", coordinates};
}