javascript - Google Maps API 3 上的天气雷达循环

Question

我正在尝试在谷歌地图上实现循环雷达动画。本站:http://mesonet.agron.iastate.edu/ogc/提供从当前时间到 60 分钟前的雷达图像。

目前，我正在加载这些图像并使用计时器将每个图像添加/删除到 map 。这在技术上可行，但结果非常不稳定。有一段时间 map 上没有可见的雷达图像。降低超时时间只会使效果变差，因为雷达图像在被移除之前没有足够的时间加载。

有没有什么技巧可以让动画变得平滑？还是我做错了？

代码

  var map;
  var imageArray = [];
  function initialize() {
    var mapOptions = {
      zoom: 5,
      center: new google.maps.LatLng(42.5, -95.5),
      mapTypeId: google.maps.MapTypeId.ROADMAP
    };
    map = new google.maps.Map(document.getElementById('map_canvas'), mapOptions);

    //Load Images and add them to imageArray
    tileNEX = new google.maps.ImageMapType({
        getTileUrl: function(tile, zoom) {
            return "http://mesonet.agron.iastate.edu/cache/tile.py/1.0.0/nexrad-n0q-900913/" + zoom + "/" + tile.x + "/" + tile.y +".png?"+ (new Date()).getTime(); 
        },
        tileSize: new google.maps.Size(256, 256),
        opacity:0.60,
        name : 'NEXRAD',
        isPng: true,
    });
    imageArray.push(tileNEX);

    tileNEX5 = new google.maps.ImageMapType({
        getTileUrl: function(tile, zoom) {
            return "http://mesonet.agron.iastate.edu/cache/tile.py/1.0.0/nexrad-n0q-900913-m05m/" + zoom + "/" + tile.x + "/" + tile.y +".png?"+ (new Date()).getTime(); 
        },
        tileSize: new google.maps.Size(256, 256),
        opacity:0.60,
        name : 'NEXRAD5',
        isPng: true,
    });
    imageArray.push(tileNEX5);

    tileNEX10 = new google.maps.ImageMapType({
        getTileUrl: function(tile, zoom) {
            return "http://mesonet.agron.iastate.edu/cache/tile.py/1.0.0/nexrad-n0q-900913-m10m/" + zoom + "/" + tile.x + "/" + tile.y +".png?"+ (new Date()).getTime(); 
        },
        tileSize: new google.maps.Size(256, 256),
        opacity:0.60,
        name : 'NEXRAD10',
        isPng: true,
        optimized: false
    });
    imageArray.push(tileNEX10);

    tileNEX15 = new google.maps.ImageMapType({
        getTileUrl: function(tile, zoom) {
            return "http://mesonet.agron.iastate.edu/cache/tile.py/1.0.0/nexrad-n0q-900913-m15m/" + zoom + "/" + tile.x + "/" + tile.y +".png?"+ (new Date()).getTime(); 
        },
        tileSize: new google.maps.Size(256, 256),
        opacity:0.60,
        name : 'NEXRAD15',
        isPng: true,
    });
    imageArray.push(tileNEX15);

    tileNEX20 = new google.maps.ImageMapType({
        getTileUrl: function(tile, zoom) {
            return "http://mesonet.agron.iastate.edu/cache/tile.py/1.0.0/nexrad-n0q-900913-m20m/" + zoom + "/" + tile.x + "/" + tile.y +".png?"+ (new Date()).getTime(); 
        },
        tileSize: new google.maps.Size(256, 256),
        opacity:0.60,
        name : 'NEXRAD20',
        isPng: true,
    });
    imageArray.push(tileNEX20);


   animateRadar(imageArray);


  }

  google.maps.event.addDomListener(window, 'load', initialize);

  function animateRadar(images) {
    map.overlayMapTypes.push(images[0]);//Add first image
    var index = 0;
    window.setInterval(function(){
        map.overlayMapTypes.pop();//Remove previous image
        index++;
        if(index >= images.length){
            index = 0;
        }

        map.overlayMapTypes.push(images[index]);//Add new image
    }, 1000);
  }

Answer 1

希望这对其他人有帮助，以下是我最终解决问题的方法。我没有添加/删除叠加图像，而是简单地更改了不透明度。这给了我一个更流畅的动画。以下示例将循环显示最近 30 分钟的雷达图像。

  var map;

  function initialize() {
    var mapOptions = {
      zoom: 5,
      center: new google.maps.LatLng(42.5, -95.5),
      mapTypeId: google.maps.MapTypeId.ROADMAP
    };
    map = new google.maps.Map(document.getElementById('map_canvas'), mapOptions);

    //Load Images and add them to imageArray
    tileNEX = new google.maps.ImageMapType({
        getTileUrl: function(tile, zoom) {
            return "http://mesonet.agron.iastate.edu/cache/tile.py/1.0.0/nexrad-n0q-900913/" + zoom + "/" + tile.x + "/" + tile.y +".png?"+ (new Date()).getTime(); 
        },
        tileSize: new google.maps.Size(256, 256),
        opacity:0.00,
        name : 'NEXRAD',
        isPng: true,
    });
    map.overlayMapTypes.push(tileNEX);

    tileNEX5 = new google.maps.ImageMapType({
        getTileUrl: function(tile, zoom) {
            return "http://mesonet.agron.iastate.edu/cache/tile.py/1.0.0/nexrad-n0q-900913-m05m/" + zoom + "/" + tile.x + "/" + tile.y +".png?"+ (new Date()).getTime(); 
        },
        tileSize: new google.maps.Size(256, 256),
        opacity:0.00,
        name : 'NEXRAD5',
        isPng: true,
    });
    map.overlayMapTypes.push(tileNEX5);

    tileNEX10 = new google.maps.ImageMapType({
        getTileUrl: function(tile, zoom) {
            return "http://mesonet.agron.iastate.edu/cache/tile.py/1.0.0/nexrad-n0q-900913-m10m/" + zoom + "/" + tile.x + "/" + tile.y +".png?"+ (new Date()).getTime(); 
        },
        tileSize: new google.maps.Size(256, 256),
        opacity:0.00,
        name : 'NEXRAD10',
        isPng: true,
        optimized: false
    });
    map.overlayMapTypes.push(tileNEX10);

    tileNEX15 = new google.maps.ImageMapType({
        getTileUrl: function(tile, zoom) {
            return "http://mesonet.agron.iastate.edu/cache/tile.py/1.0.0/nexrad-n0q-900913-m15m/" + zoom + "/" + tile.x + "/" + tile.y +".png?"+ (new Date()).getTime(); 
        },
        tileSize: new google.maps.Size(256, 256),
        opacity:0.00,
        name : 'NEXRAD15',
        isPng: true,
    });
    map.overlayMapTypes.push(tileNEX15);

    tileNEX20 = new google.maps.ImageMapType({
        getTileUrl: function(tile, zoom) {
            return "http://mesonet.agron.iastate.edu/cache/tile.py/1.0.0/nexrad-n0q-900913-m20m/" + zoom + "/" + tile.x + "/" + tile.y +".png?"+ (new Date()).getTime(); 
        },
        tileSize: new google.maps.Size(256, 256),
        opacity:0.00,
        name : 'NEXRAD20',
        isPng: true,
    });
    map.overlayMapTypes.push(tileNEX20);

    tileNEX25 = new google.maps.ImageMapType({
        getTileUrl: function(tile, zoom) {
            return "http://mesonet.agron.iastate.edu/cache/tile.py/1.0.0/nexrad-n0q-900913-m25m/" + zoom + "/" + tile.x + "/" + tile.y +".png?"+ (new Date()).getTime(); 
        },
        tileSize: new google.maps.Size(256, 256),
        opacity:0.00,
        name : 'NEXRAD25',
        isPng: true,
    });
    map.overlayMapTypes.push(tileNEX25);

    tileNEX30 = new google.maps.ImageMapType({
        getTileUrl: function(tile, zoom) {
            return "http://mesonet.agron.iastate.edu/cache/tile.py/1.0.0/nexrad-n0q-900913-m30m/" + zoom + "/" + tile.x + "/" + tile.y +".png?"+ (new Date()).getTime(); 
        },
        tileSize: new google.maps.Size(256, 256),
        opacity:0.00,
        name : 'NEXRAD30',
        isPng: true,
    });
    map.overlayMapTypes.push(tileNEX30);

    animateRadar();


  }

  google.maps.event.addDomListener(window, 'load', initialize);

  function animateRadar() {
    var index = map.overlayMapTypes.getLength() - 1;

    window.setInterval(function(){

        map.overlayMapTypes.getAt(index).setOpacity(0.00);

        index--;
        if(index < 0){
            index = map.overlayMapTypes.getLength() - 1;
        }
        map.overlayMapTypes.getAt(index).setOpacity(0.60);
    }, 400);
  }