自定义符号动画不遵循多段线路径

我不知道为什么你认为anchor不能与Symbol一起使用，文档中有描述：

符号对象规范

anchor | Type：Point |符号相对于标记或多段线的位置。符号路径的坐标分别由锚点的x和y坐标向左和向上平移。默认情况下，符号定位在（0，0）处。位置表示在与符号路径相同的坐标系中。

如果我设置了它和正确的旋转，符号会跟随多段线：

概念验证小提琴

代码片段：

var map;
function initMap() {
  map = new google.maps.Map(document.getElementById('map'), {
    center: {
      lat: 55.696242,
      lng: 12.593639
    },
    zoom: 4
  });
  var lineSymbol = {
    path: 'M 157.98695,184.38488 L 173.37483,168.20017 C 182.38616,159.18884 197.56012,162.31477 197.56012,162.31477 L 242.58958,168.47612 L 265.39575,146.16045 C 277.41087,134.35989 288.26269,152.4142 283.54247,158.63631 L 271.83305,172.24635 L 320.32641,181.22794 L 336.78707,162.03882 C 354.38063,141.01237 367.47041,159.95529 359.53185,171.11218 L 348.89521,184.56906 L 421.75804,194.07153 C 484.40828,133.78139 509.98537,108.77262 526.46939,123.63021 C 543.05967,138.5836 513.71315,168.38877 456.64135,227.17701 L 467.00204,302.24678 L 482.26714,289.52597 C 491.27847,282.01653 507.27901,294.06392 490.75822,309.72648 L 469.76089,329.52825 L 478.61969,378.66527 L 491.73923,368.58052 C 503.32523,359.35463 517.39476,371.55518 501.7322,388.29052 L 480.88803,409.28786 C 480.02981,409.93153 487.69305,452.38631 487.69305,452.38631 C 492.41327,473.19821 480.67347,480.80195 480.67347,480.80195 L 466.35838,493.27782 L 411.97962,339.67439 C 407.47395,326.15738 396.0546,311.47862 376.97351,313.22076 C 366.8894,314.29354 341.41552,331.49026 337.98263,335.56682 L 279.00579,392.27531 C 277.5039,393.34809 288.07915,465.99635 288.07915,465.99635 C 288.07915,468.14191 269.38054,492.66454 269.38054,492.66454 L 232.01433,426.14725 L 213.56128,434.7301 L 224.35108,417.93211 L 157.06733,379.9526 L 182.29502,361.49956 C 194.31014,364.28878 257.3034,371.36975 258.59073,370.72608 C 258.59073,370.72608 309.88762,319.85344 312.81633,316.77643 C 329.76623,298.96831 335.46935,292.31456 338.04402,283.51778 C 340.6208,274.71377 336.23117,261.81195 309.62838,245.4769 C 272.93937,222.94855 157.98695,184.38488 157.98695,184.38488 z',
    scale: 0.025,
    rotation: -45,
    strokeColor: '#000',
    fillColor: '#000',
    fillOpacity: 1,
    anchor: new google.maps.Point(500, 170)
  };
  var pathOptions = {
    geodesic: true,
    strokeColor: 'green',
    strokeOpacity: 1.0,
    strokeWeight: 2,
    icons: [{
      icon: lineSymbol,
      offset: '100%'
    }]
  };
  var path = new google.maps.Polyline(pathOptions);
  var start_point = new google.maps.LatLng(55.696242, 12.593639);
  var end_point = new google.maps.LatLng(35.701369, 139.664309);
  path.getPath().setAt(0, start_point);
  path.getPath().setAt(1, end_point);
  /*    var m = new google.maps.Marker({
          map: map,
          position: start_point,
          icon: lineSymbol,
          zIndex: -1
      });
      var p = new google.maps.Marker({
          map: map,
          position: start_point,
          icon: {
              url: "https://maps.gstatic.com/intl/en_us/mapfiles/markers2/measle.png",
              size: new google.maps.Size(7, 7),
              anchor: new google.maps.Point(3.5, 3.5)
          },
          zIndex: 1
      });
  */
  path.setMap(map);
  animateCircle(path);
}
function animateCircle(line) {
  var count = 0;
  window.setInterval(function() {
    count = (count + 1) % 200;
    var icons = line.get('icons');
    icons[0].offset = (count / 2) + '%';
    line.set('icons', icons);
  }, 200);
}
google.maps.event.addDomListener(window, "load", initMap);

html,
body,
#map {
  height: 100%;
  width: 100%;
  margin: 0px;
  padding: 0px
}

<script src="https://maps.googleapis.com/maps/api/js"></script>
<div id="map"></div>