
            linewidth: 1,
            color: '#0d37ff',
            opacity: 0.1,
            transparent: true,
            blending: THREE.AdditiveBlending
        });
        var lineTrails;

        function addLines() {
            // data from https://github.com/maptalks/maptalks.odline
            fetch('./../demo/data/lines.json').then(function (res) {
                return res.json();
            }).then(function (geojson) {
                var lineStrings = geojson.map(function (feature) {
     