let viewer = new Cesium.Viewer("viewerContainer")
let measure = new Cesium.Measure(viewer)
// 空间距离
measure.drawLineMeasureGraphics({ clampToGround: clampToGround, callback: () => { } });
// 空间面积
measure.drawAreaMeasureGraphics({ clampToGround: clampToGround, callback: () => { } });
// 三维量测
measure.drawTrianglesMeasureGraphics({ callback: () => { } });
// 清除
measure._drawLayer.entities.removeAll();