PolylineCollection

new Cesium.PolylineCollection(options)

engine/Source/Scene/PolylineCollection.js 116

一个可渲染的折线集合。

示例折线

Polylines are added and removed from the collection using PolylineCollection#add and PolylineCollection#remove.

Performance:

For best performance, prefer a few collections, each with many polylines, to many collections with only a few polylines each. Organize collections so that polylines with the same update frequency are in the same collection, i.e., polylines that do not change should be in one collection; polylines that change every frame should be in another collection; and so on.

Name	Type	Description
options	object	optional Object with the following properties: Name Type Default Description modelMatrix Matrix4 Matrix4.IDENTITY optional 将每条折线从模型坐标变换到世界坐标的 4x4 变换矩阵。 debugShowBoundingVolume boolean false optional 仅用于调试。确定是否显示此图元命令的包围球。 show boolean true optional 确定集合中的折线是否显示。

Example:

// Create a polyline collection with two polylines
const polylines = new Cesium.PolylineCollection();
polylines.add({
  positions : Cesium.Cartesian3.fromDegreesArray([
    -75.10, 39.57,
    -77.02, 38.53,
    -80.50, 35.14,
    -80.12, 25.46]),
  width : 2
});

polylines.add({
  positions : Cesium.Cartesian3.fromDegreesArray([
    -73.10, 37.57,
    -75.02, 36.53,
    -78.50, 33.14,
    -78.12, 23.46]),
  width : 4
});

See:

• PolylineCollection#add
• PolylineCollection#remove
• Polyline
• LabelCollection

Members

Default Value: false

Default Value: Matrix4.IDENTITY

Default Value: true

Methods

Performance:

After calling add, PolylineCollection#update is called and the collection's vertex buffer is rewritten - an O(n) operation that also incurs CPU to GPU overhead. For best performance, add as many polylines as possible before calling update.

Returns:

Throws:

• DeveloperError : 此对象已被销毁，即已调用 destroy()。

Example:

// Example 1:  Add a polyline, specifying all the default values.
const p = polylines.add({
  show : true,
  positions : ellipsoid.cartographicArrayToCartesianArray([
           Cesium.Cartographic.fromDegrees(-75.10, 39.57),
           Cesium.Cartographic.fromDegrees(-77.02, 38.53)]),
  width : 1
});

See:

• PolylineCollection#remove
• PolylineCollection#removeAll
• PolylineCollection#update

Returns:

See:

• PolylineCollection#get

Throws:

• DeveloperError : 此对象已被销毁，即已调用 destroy()。

Example:

polylines = polylines && polylines.destroy();

See:

• PolylineCollection#isDestroyed

Performance:

If polylines were removed from the collection and PolylineCollection#update was not called, an implicit O(n) operation is performed.

Returns:

Throws:

• DeveloperError : 此对象已被销毁，即已调用 destroy()。

Example:

// Toggle the show property of every polyline in the collection
const len = polylines.length;
for (let i = 0; i < len; ++i) {
  const p = polylines.get(i);
  p.show = !p.show;
}

See:

• PolylineCollection#length

Returns:

See:

• PolylineCollection#destroy

Performance:

After calling remove, PolylineCollection#update is called and the collection's vertex buffer is rewritten - an O(n) operation that also incurs CPU to GPU overhead. For best performance, remove as many polylines as possible before calling update. If you intend to temporarily hide a polyline, it is usually more efficient to call Polyline#show instead of removing and re-adding the polyline.

Returns:

Throws:

• DeveloperError : 此对象已被销毁，即已调用 destroy()。

Example:

const p = polylines.add(...);
polylines.remove(p);  // Returns true

See:

• PolylineCollection#add
• PolylineCollection#removeAll
• PolylineCollection#update
• Polyline#show

Performance:

O(n). It is more efficient to remove all the polylines from a collection and then add new ones than to create a new collection entirely.

Throws:

• DeveloperError : 此对象已被销毁，即已调用 destroy()。

Example:

polylines.add(...);
polylines.add(...);
polylines.removeAll();

See:

• PolylineCollection#add
• PolylineCollection#remove
• PolylineCollection#update

Throws:

• RuntimeError : 渲染带有逐实例属性的图元需要顶点纹理获取支持。顶点纹理图像单元的最大数量必须大于零。