在铯中显示折线（具有一定高度）

Question

谁能告诉我这段代码有什么问题？

    Cesium.Math.setRandomNumberSeed(1234);

    var viewer = new Cesium.Viewer('cesiumContainer');
    var entities = viewer.entities;
    var boxes = entities.add(new Cesium.Entity());
    var polylines = new Cesium.PolylineCollection();

    //Create the entities and assign each entity's parent to the group to which it belongs.
    for (var i = 0; i < 5; ++i) {
        var height = 100000.0 + (200000.0 * i);
        entities.add({
            parent : boxes,
            position : Cesium.Cartesian3.fromDegrees(-106.0, 45.0, height),
            box : {
                dimensions : new Cesium.Cartesian3(90000.0, 90000.0, 90000.0),
                material : Cesium.Color.fromRandom({alpha : 1.0})
            }
        });
        entities.add({
            parent : polylines,
            position : Cesium.Cartesian3.fromDegrees(-86.0, 55.0, height),
            polyline : {
                width : new Cesium.ConstantProperty(2),
                material : Cesium.Color.fromRandom({alpha : 1.0}),
                followSurface : new Cesium.ConstantProperty(false)
            }
        });
    }
    viewer.zoomTo(viewer.entities);

它在给定坐标处显示框，但是当我尝试绘制折线时，会出现以下错误： 未捕获的类型错误：无法读取未定义的属性“推送”（https://cesiumjs.org/Cesium/Source/DataSources/Entity.js 的第 300 行）

我想要这样的东西 https://cesiumjs.org/Cesium/Apps/Sandcastle/index.html?src=Custom%20DataSource.html&label=Showcases

提前致谢。

Answer 1

您正在将 Entity API（具有名称和描述的可跟踪实体的高级 API）与 Primitive Graphics API（下面的层，仅显示图形基元）混合。

编辑：看起来 Scott Reynolds 也在mailing list 上为您回答了这个问题，并且您发布了一个后续问题。这里我借用了 Scott 的“垂直线”代码，删除了“父”关系，因为它们似乎没有在这里使用，并为所有实体添加了可点击的信息框描述。

Cesium.Math.setRandomNumberSeed(1234);

var viewer = new Cesium.Viewer('cesiumContainer');
var entities = viewer.entities;

var prevHeight = 0.0;
for (var i = 0; i < 5; ++i) {
    var height = 100000.0 + (200000.0 * i);
    entities.add({
        name : 'Box ' + i,
        description : 'This box is at height: ' + height.toLocaleString() + ' m',
        position : Cesium.Cartesian3.fromDegrees(-106.0, 45.0, height),
        box : {
            dimensions : new Cesium.Cartesian3(90000.0, 90000.0, 90000.0),
            material : Cesium.Color.fromRandom({alpha : 1.0})
        }
    });
    entities.add({
        name : 'Line ' + i,
        description : 'This line is from height ' + prevHeight.toLocaleString() +
            ' m to height ' + height.toLocaleString() + ' m',
        position : Cesium.Cartesian3.fromDegrees(-86.0, 55.0, height),
        polyline : {
            positions: [
                Cesium.Cartesian3.fromDegrees(-86.0, 55.0, prevHeight),
                Cesium.Cartesian3.fromDegrees(-86.0, 55.0, height)
            ],
            width : new Cesium.ConstantProperty(2),
            material : Cesium.Color.fromRandom({alpha : 1.0}),
            followSurface : new Cesium.ConstantProperty(false)
        }
    });

    prevHeight = height;
}
viewer.zoomTo(viewer.entities);