铯:选择实体并检索WMS的信息 [英] Cesium: picking entity and retrieving info of WMS
问题描述
我开发了建筑物的3D查看器.我现在要添加的是在建筑物实体下方选择WMS(Web地图服务)的内容.
I have developed a 3D viewer of buildings. What I'm trying to add now is the selection of the content of a WMS (Web Map Service) below the building entities.
基本上,我希望能够在用户左键单击的位置选择建筑物.建筑物的颜色应该改变(起作用).我想在用户单击的位置检索Web Map Service的信息.
Basically, I want to be able to select the building at the position were the user left clicks. The colour of the building should change (which works). And I want to retrieve the information of the Web Map Service at the position were the user clicked.
这是我到目前为止编写的代码:
This is what I have coded so far:
var pickColor = Cesium.Color.CYAN.withAlpha(0.7);
var selectedEntity = new Map();
handler = new Cesium.ScreenSpaceEventHandler(viewer.scene.canvas);
handler.setInputAction(function(click) {
var pickedObject = viewer.scene.pick(click.position);
if (Cesium.defined(pickedObject)) {
var entityId = pickedObject.id._id;
var oldColor = buildingMap.get(entityId).polygon.material.color;
buildingMap.get(entityId).polygon.material.color = pickColor;
selectedEntity.set(entityId, oldColor);
var currentLayer = viewer.scene.imageryLayers.get(1);
if (typeof currentLayer !== 'undefined') {
var info = currentLayer._imageryProvider._tileProvider.getTileCredits(click.position.x, click.position.y, 0);
}
}
}, Cesium.ScreenSpaceEventType.LEFT_CLICK);
但是,我的变量"info"保持未定义状态,而我希望它返回一个数组.
However, my variable "info" stays undefined, whereas I expect it to return an array.
推荐答案
对于WMS,您需要使用wms GetFeatureInfo
功能:
For WMS you need to use the wms GetFeatureInfo
capability:
var pickRay = viewer.camera.getPickRay(windowPosition);
var featuresPromise = viewer.imageryLayers.pickImageryLayerFeatures(pickRay, viewer.scene);
if (!Cesium.defined(featuresPromise)) {
console.log('No features picked.');
} else {
Cesium.when(featuresPromise, function(features) {
// This function is called asynchronously when the list if picked features is available.
console.log('Number of features: ' + features.length);
if (features.length > 0) {
console.log('First feature name: ' + features[0].name);
}
});
}
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