openlayers:使用MVT VectorTileSource集群是不可能的？
openlayers:使用MVT VectorTileSource集群是不可能的？
提问于 2019-03-14 19:28:50
我是openlayers的新手，我想对矢量数据使用cluster函数。
如果我在群集选项中指定一个MVT VectorTileSource作为source:，这似乎不起作用?！
下面的代码。它在没有集群的情况下工作良好。
它不受支持吗？谢谢你，彼得
var vectorTileSource = new VectorTileSource({
format: new MVT(),
url:
'http://xxxx/geoserver/gwc/service/tms/1.0.0/' + 'airports:airports' +
'@EPSG%3A'+'900913'+
'@pbf/{z}/{x}/{-y}.pbf'
});
var clusterSource = new Cluster({
distance: 30,
source: vectorTileSource
});
var clusterLayer = new VectorTileLayer({
source: vectorTileSource, //----> this works
source: clusterSource, // ---> does NOT work
style: clusterStyle
});回答 2
Stack Overflow用户
回答已采纳
发布于 2019-03-15 04:17:32
可能期望将MVT瓦片加载到向量源的代码不会产生任何功能和错误。请参阅https://gis.stackexchange.com/questions/225615/how-to-use-mapbox-vector-tiles-as-a-vector-source-in-ol3-so-that-labelling-will
然而，可以在法线矢量源中复制矢量瓦片图层中的要素，这可以用于聚类源(并在具有轮廓密度的测试中工作)
var vtLayer = new ol.layer.VectorTile({
source: new ol.source.VectorTile({
format new ol.format.MVT({
featureClass: ol.Feature // important
}),
....
....
}),
style: [] // layer must be added to map to load features, use empty style to avoid display
});
map.addLayer(vtLayer);
var vSource = new ol.source.Vector(); // use this as the source for a cluster source
var featuresForZ = [];
var viewZ;
function vsRefresh() {
vSource.clear();
if (featuresForZ[viewZ]) {
vSource.addFeatures(featuresForZ[viewZ]);
}
}
vtLayer.getSource().on('tileloadend', function(evt) {
var z = evt.tile.getTileCoord()[0];
var features = evt.tile.getFeatures();
features.forEach(function (feature) {
// each vector tile has its own set of feature ids, but duplicates are not allowed in normal vector sources
feature.setId(undefined);
});
if (!Array.isArray(featuresForZ[z])) { featuresForZ[z] = []; }
featuresForZ[z] = featuresForZ[z].concat(features);
if (z === viewZ) {
vsRefresh();
}
});
map.getView().on('change:resolution', function() {
// use VT features from the tile z level corresponding to view resolution
var newZ = vtLayer.getSource().getTileGrid().getZForResolution(map.getView().getResolution());
if (newZ !== viewZ) {
viewZ = newZ;
vsRefresh();
}
});
// now create the cluster layer
var vLayer = new ol.layer.Vector({
source: new ol.source.Cluster({
source: vSource,
geometryFunction: function(feature){
// test data is linestrings
return new ol.geom.Point(ol.extent.getCenter(feature.getGeometry().getExtent()));
},
}),
style: function(feature) {
return new ol.style.Style({
image: new ol.style.Circle({
radius: feature.get('features').length * 5,
fill: new ol.style.Fill({ color: 'black' })
})
});
}
});
map.addLayer(vLayer);Stack Overflow用户
发布于 2019-03-14 19:58:23
(仍然没有足够的声誉来评论)根据文档，集群需要一个VectorSource。VectorTile源码和VectorTile源码的OpenLayers是不同的，因为它们可以是非常不同的东西。
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原文链接：
https://stackoverflow.com/questions/55161380
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