Cesium 学习笔记 - cytggit/Map-openlayers GitHub Wiki

• 去除Cesium的logo和版本信息

    viewer._cesiumWidget._creditContainer.style.display="none";  
  

• 对entity的操作：添加、隐藏、修改、去除、居中显示

    Var rainEntity=viewer.entities.add({
  
      id: "rain",
  
      name: 'RainStation',
  
      parent: rainLayer3D,                
  
      position: Cesium.Cartesian3.fromDegrees(lon, lat),
  
      billboard: {
  
        image: 'images/pointIcons/rain1.png',
  
        scale:0.7,
  
        verticalOrigin: Cesium.VerticalOrigin.BOTTOM
  
      },
  
      label: {
  
          text: rainfall,
  
          font: '12px SimHei ',
  
          Width: 3,
  
          style: Cesium.LabelStyle.FILL,
  
          fillColor: Cesium.Color.AQUA,
  
          horizontalOrigin: Cesium.HorizontalOrigin.CENTER,
  
          verticalOrigin: Cesium.VerticalOrigin.TOP
  
      }
  
    });  //添加
  
    viewer.entities.getById("rain").show = false;   //隐藏
  
    viewer.entities.getById("rain").label.text= "drp";   //修改属性
  
    viewer.entities.removeAll();  //移除所有
  
    viewer.zoomTo(rainEntity);   //居中显示
  

• 去掉entity的双击事件

问题所在：双击entity，会放大视图，entity居中显示，且鼠标左键失去移动功能，鼠标滚轮失去作用

解决问题：

    viewer.screenSpaceEventHandler.setInputAction(function(){},Cesium.ScreenSpaceEventType.LEFT_DOUBLE_CLICK );

• 获取当前视角高度

    var scene = viewer.scene;
  
    var ellipsoid = scene.globe.ellipsoid;
  
    var height=ellipsoid.cartesianToCartographic(viewer.camera.position).height;
  

• 获取某个经纬度在屏幕上的位置

    var position = Cesium.Cartesian3.fromDegrees(lon, lat);
  
    var clickPt =Cesium.SceneTransforms.wgs84ToWindowCoordinates (viewer.scene, position);
  
    var screenX=clickPt.x;
  
    var screenY=clickPt.y;
  

• 获取三维场景屏幕中心点坐标

    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;
  

• 响应鼠标单击等事件，获取屏幕点击坐标

    var handler = new Cesium.ScreenSpaceEventHandler(canvas);
  
    handler.setInputAction(function(click){},Cesium.ScreenSpaceEventType.LEFT_CLICK);
  
    var clickX=click.position.x;
  
    var clickY=click.position.y;
  

这个LEFT_CLICK可以换成MIDDLE_CLICK、MOUSE_MOVE等就会响应滚轮点击、鼠标移动等事件，见参考文档中的ScreenSpaceEventType()，注意不同的事件中，function中的click会有不同的属性，可console.log(click)，找到所需

• 跟踪相机视角的改变

    viewer.camera.moveStart.addEventListener(function(moveStartPosition){})；
  
    viewer.camera.moveEnd.addEventListener(function(moveEndPosition){})；
  

其实还有个

    viewer.camera.changed.addEventListener(function(moveEndPosition){})，但我不会用，总是提示changed不存在，但是camera的参考文档中这个changed和moveStart和moveEnd都可以addEventListener

• 使视角到达某一地点

    viewer.camera.setView({
  
      destination: Cesium.Cartesian3.fromDegrees(lon, lat, height),
  
      orientation: {
  
        heading : curHeading,  //左右偏移
  
        pitch : curPitch,   //上下偏移
  
        roll : 0.0                           
  
     }
  
    });