【问题原因】三维线需要加载到场景中开启特效再切场景缓存，发布工作空间，scene.open来加载，比如示例代码：
var promise = scene.open('http://localhost:8090/iserver/services/3D-YouYanSeDeTeXiaoXian/rest/realspace');
Cesium.when(promise, function(layers) {
var layer = scene.layers.find('MGX_TX@NewDatasource');
var s3mpolylineEffect = layer.effect;
var EffectSetting = s3mpolylineEffect.getEffectSetting();
s3mpolylineEffect.setValue('PolylineType', 1);//间断线效果
s3mpolylineEffect.setValue('Width', 15);//线宽
s3mpolylineEffect.setValue('Color', Cesium.Color.AQUAMARINE);
})
