Cesium视角监听回调，获取中心点坐标、高度、当前可视区域范围
作者：互联网
var token = "0b018552994f71a9467d24461a8f8238";
var viewer = new Cesium.Viewer('cesiumContainer', {
animation: false, //是否创建动画小器件，左下角仪表
baseLayerPicker: false, //是否显示图层选择器
fullscreenButton: false, //是否显示全屏按钮
geocoder: false, //是否显示geocoder小器件，右上角查询按钮
homeButton: false, //是否显示Home按钮
infoBox: false, //是否显示信息框
sceneModePicker: false, //是否显示3D/2D选择器
selectionIndicator: false, //是否显示选取指示器组件
timeline: false, //是否显示时间轴
navigationHelpButton: false, //是否显示右上角的帮助按钮
scene3DOnly: true, //如果设置为true，则所有几何图形以3D模式绘制以节约GPU资源
imageryProvider: new Cesium.WebMapTileServiceImageryProvider({
url: "http://t0.tianditu.gov.cn/img_w/wmts?service=wmts&request=GetTile&version=1.0.0&LAYER=img&tileMatrixSet=w&TileMatrix={TileMatrix}&TileRow={TileRow}&TileCol={TileCol}&style=default&format=tiles&tk=" +
token,
layer: "tdtImgBasicLayer",
style: "default",
format: "image/jpeg",
show: false
})
});
viewer.imageryLayers.addImageryProvider(new Cesium.WebMapTileServiceImageryProvider({
url: "http://t0.tianditu.gov.cn/cia_w/wmts?service=wmts&request=GetTile&version=1.0.0&LAYER=cia&tileMatrixSet=w&TileMatrix={TileMatrix}&TileRow={TileRow}&TileCol={TileCol}&style=default&format=tiles&tk=" +
token,
layer: "tdtImgAnnoLayer",
style: "default",
format: "image/jpeg",
tileMatrixSetID: "GoogleMapsCompatible",
show: false
}));
/* 三维球转动添加监听事件 */
viewer.camera.changed.addEventListener(function (percentage) {
getCenterPosition();
getCurrentExtent();
// 打印中心点坐标、高度、当前范围坐标
console.log(getCenterPosition());
console.log("bounds",getCurrentExtent());
});
/* 获取camera高度 */
function getHeight() {
if (viewer) {
var scene = viewer.scene;
var ellipsoid = scene.globe.ellipsoid;
var height = ellipsoid.cartesianToCartographic(viewer.camera.position).height;
return height;
}
}
/* 获取camera中心点坐标 */
function getCenterPosition() {
var result = viewer.camera.pickEllipsoid(new Cesium.Cartesian2(viewer.canvas.clientWidth / 2, viewer.canvas
.clientHeight / 2));
var curPosition = Cesium.Ellipsoid.WGS84.cartesianToCartographic(result);
var lon = curPosition.longitude * 180 / Math.PI;
var lat = curPosition.latitude * 180 / Math.PI;
var height = getHeight();
return {
lon: lon,
lat: lat,
height: height
};
}
function getCurrentExtent() {
// 范围对象
var extent = {};
// 得到当前三维场景
var scene = viewer.scene;
// 得到当前三维场景的椭球体
var ellipsoid = scene.globe.ellipsoid;
var canvas = scene.canvas;
// canvas左上角
var car3_lt = viewer.camera.pickEllipsoid(new Cesium.Cartesian2(0, 0), ellipsoid);
// canvas右下角
var car3_rb = viewer.camera.pickEllipsoid(new Cesium.Cartesian2(canvas.width, canvas.height), ellipsoid);
// 当canvas左上角和右下角全部在椭球体上
if (car3_lt && car3_rb) {
var carto_lt = ellipsoid.cartesianToCartographic(car3_lt);
var carto_rb = ellipsoid.cartesianToCartographic(car3_rb);
extent.xmin = Cesium.Math.toDegrees(carto_lt.longitude);
extent.ymax = Cesium.Math.toDegrees(carto_lt.latitude);
extent.xmax = Cesium.Math.toDegrees(carto_rb.longitude);
extent.ymin = Cesium.Math.toDegrees(carto_rb.latitude);
}
// 当canvas左上角不在但右下角在椭球体上
else if (!car3_lt && car3_rb) {
var car3_lt2 = null;
var yIndex = 0;
do {
// 这里每次10像素递加，一是10像素相差不大，二是为了提高程序运行效率
yIndex <= canvas.height ? yIndex += 10 : canvas.height;
car3_lt2 = viewer.camera.pickEllipsoid(new Cesium.Cartesian2(0, yIndex), ellipsoid);
} while (!car3_lt2);
var carto_lt2 = ellipsoid.cartesianToCartographic(car3_lt2);
var carto_rb2 = ellipsoid.cartesianToCartographic(car3_rb);
extent.xmin = Cesium.Math.toDegrees(carto_lt2.longitude);
extent.ymax = Cesium.Math.toDegrees(carto_lt2.latitude);
extent.xmax = Cesium.Math.toDegrees(carto_rb2.longitude);
extent.ymin = Cesium.Math.toDegrees(carto_rb2.latitude);
}
// 获取高度
extent.height = Math.ceil(viewer.camera.positionCartographic.height);
return extent;
}
标签：canvas,false,viewer,car3,var,中心点,Cesium,监听 来源： https://www.cnblogs.com/hustshu/p/16194053.html