cesium 一些功能

1.获取相机参数

function getcameraPosInfo () {
    // 获取 相机姿态信息
    let head = viewer.scene.camera.heading
    let pitch = viewer.scene.camera.pitch
    let roll = viewer.scene.camera.roll
    let info = { head: head, pitch: pitch, roll: roll }
    // 获取位置 wgs84的地心坐标系，x,y坐标值以弧度来表示
    let position = viewer.scene.camera.positionCartographic // with longitude and latitude expressed in radians and height in meters.
    // 以下方式也可以获取相机位置只是返回的坐标系不一样
    // var position = viewer.scene.camera.position //cartesian3 空间直角坐标系
    // var ellipsoid = scene.globe.ellipsoid;
    // var position
=ellipsoid.cartesianToCartographic(viewer.scene.camera.position)//
    // 弧度转经纬度
    let longitude = Cesium.Math.toDegrees(position.longitude)
    let latitude = Cesium.Math.toDegrees(position.latitude)
    let height = position.height
    return { lng: longitude, lat: latitude, h: height, mat: info }
}

2.获取相机中心点坐标 

/* 获取camera高度  */
function getHeight () {
    if (viewer) {
    let scene = viewer.scene
    let ellipsoid = scene.globe.ellipsoid
    let height = ellipsoid.cartesianToCartographic(viewer.camera.position).height
    return height
    }
}
/* 获取屏幕中心点坐标 */
function getCenterPosition () {
    let result = viewer.camera.pickEllipsoid(new Cesium.Cartesian2(viewer.canvas.clientWidth / 2, viewer.canvas.clientHeight / 2))
    let curPosition = Cesium.Ellipsoid.WGS84.cartesianToCartographic(result)
    let lon = curPosition.longitude * 180 / Math.PI
    let lat = curPosition.latitude * 180 / Math.PI
    let height = getHeight()
    return {
        lon: lon,
        lat: lat,
        height: height
    }
}

3.锁定和解除锁定相机视角

let center = Cesium.Cartesian3.fromDegrees(prosition.lon, prosition.lat)// camera视野中心点坐标
let heading = Cesium.Math.toRadians(parseFloat(heading_show.value))
let pitch = Cesium.Math.toRadians(-45.0)
let range = prosition.height
//锁定视角
viewer.camera.lookAt(center, new Cesium.HeadingPitchRange(heading, pitch, range))
 
 
//解除锁定
viewer.camera.lookAtTransform(Cesium.Matrix4.IDENTITY)

4.3D场景和2D场景切换

viewer.scene.mode = Cesium.SceneMode.SCENE3D // 三维场景
 
viewer.scene.mode = Cesium.SceneMode.SCENE2D // 平面场景

5.获取相机位置，姿态 

 // 获取相机位置，姿态等
        function getcameraPosInfo () {
          // 获取 相机姿态信息
          let head = viewer.scene.camera.heading
          let pitch = viewer.scene.camera.pitch
          let roll = viewer.scene.camera.roll
          let info = { head: head, pitch: pitch, roll: roll }
          // 获取位置 wgs84的地心坐标系，x,y坐标值以弧度来表示
          let position = viewer.scene.camera.positionCartographic // with longitude and latitude expressed in radians and height in meters.
          // 以下方式也可以获取相机位置只是返回的坐标系不一样
          // var position = viewer.scene.camera.position //cartesian3 空间直角坐标系
          // var ellipsoid = scene.globe.ellipsoid;
          // var position =ellipsoid.cartesianToCartographic(viewer.scene.camera.position)//
          // 弧度转经纬度
          let longitude = Cesium.Math.toDegrees(position.longitude)
          let latitude = Cesium.Math.toDegrees(position.latitude)
          let height = position.height
          return { lon: longitude, lat: latitude, height: height, mat: info }
        }