cesium场景缩放，旋转，倾斜

参考文章：
自定义Cesium缩放控件
cesium地图缩放，旋转，倾斜

// 可根据高度进行缩放的控制
function zoomInByMove(flag){
     var position = viewer.camera.positionCartographic;
     // 1表示放大，0表示缩小
     if(flag){
         viewer.camera.moveForward(position.height * 0.5)
     }
     else{
         viewer.camera.moveBackward(position.height * 0.5)
     }
 }
//绑定两个控件事件
document.getElementById('zoomIn').addEventListener('click', function (){
      zoomInByMove(1);
  })
  document.getElementById('zoomOut').addEventListener('click', function (){
      zoomInByMove(0);
  })

/定义初始缩放，值可以改动，以下括号里的值可以看情况自己设置。/

viewer.camera.zoomIn(0);

/放大/

viewer.camera.zoomIn(1000);

/缩小/

viewer.camera.zoomOut(1000);

/左旋转/

viewer.camera.rotateLeft(Cesium.Math.toDegrees(0.005).toFixed(2));
/*viewer.camera.rotateLeft(0.000001);*/

/右旋转/

viewer.camera.rotateRight(Cesium.Math.toDegrees(0.005).toFixed(2));
/*viewer.camera.rotateRight(0.000001);*/

/上倾斜，偏左旋转/

viewer.camera.twistRight(Cesium.Math.toDegrees(0.005).toFixed(2));

/下倾斜，偏右旋转/

viewer.camera.twistLeft(Cesium.Math.toDegrees(0.005).toFixed(2));