【解决办法】
//特效圆环
viewer.scene.scanEffect.show = true
viewer.scene.scanEffect.mode =Cesium.ScanEffectMode.CIRCLE;
viewer.scene.scanEffect.textureUrl = "./images/环状扫描纹理2.jpg";
viewer.scene.scanEffect.centerPostion = new Cesium.Cartesian3.fromDegrees(106.44175584992466, 29.51555839072486, 1);