转载：Cesium Cartesian3 和经纬度以及屏幕坐标等之间的转换

一、经纬度转换为世界坐标

1.Cesium.Cartesian3.fromDegrees(longitude, latitude, height, ellipsoid, result)

2.var ellipsoid=viewer.scene.globe.ellipsoid;

 var cartographic=Cesium.Cartographic.fromDegrees(lng,lat,alt);

 var cartesian3=ellipsoid.cartographicToCartesian(cartographic);

3.

/**
 * WGS84坐标系转笛卡尔坐标系
 * @param point
 * @return {{x: *, y: *, z: *}}
 * @constructor
 */
var WGS84_to_Cartesian3 = function (point) {
    var car33 = Cesium.Cartesian3.fromDegrees(point.lng, point.lat, point.alt);
    var x = car33.x;
    var y = car33.y;
    var z = car33.z;
    return {x: x, y: y, z: z};
}

二、 世界坐标转换为经纬度

1.var ellipsoid=viewer.scene.globe.ellipsoid;

var cartesian3=new Cesium.cartesian3(x,y,z);

var cartographic=ellipsoid.cartesianToCartographic(cartesian3);

var lat=Cesium.Math.toDegrees(cartograhphic.latitude);

var lng=Cesium.Math.toDegrees(cartograhpinc.longitude);

var alt=cartographic.height;

2.Cartographic.fromCartesian

3.

/**
 * 笛卡尔坐标系转WGS84坐标系
 * @param point
 * @return {{lat: *, lng: *, alt: *}}
 * @constructor
 */
var Cartesian3_to_WGS84 = function (point) {
    var cartesian33 = new Cesium.Cartesian3(point.x, point.y, point.z);
    var cartographic = Cesium.Cartographic.fromCartesian(cartesian33);
    var lat = Cesium.Math.toDegrees(cartographic.latitude);
    var lng = Cesium.Math.toDegrees(cartographic.longitude);
    var alt = cartographic.height;
    return {lng: lng, lat: lat, alt: alt};
}

三、屏幕坐标和世界坐标相互转换

1.var pick1= new Cesium.Cartesian2(0,0);    

var cartesian = viewer.scene.globe.pick(viewer.camera.getPickRay(pick1),viewer.scene);

2.Cesium.SceneTransforms.wgs84ToWindowCoordinates(scene, Cartesian3);