PolylineCollection

查阅Mars3D API

new Cesium.PolylineCollection(options)

engine/Source/Scene/PolylineCollection.js 117

A renderable collection of polylines.

Example polylines

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.

参数名称	类型	描述信息
options	object	可选 Object with the following properties: 参数名称 类型 默认值 描述信息 modelMatrix Matrix4 Matrix4.IDENTITY 可选 The 4x4 transformation matrix that transforms each polyline from model to world coordinates. debugShowBoundingVolume boolean false 可选 For debugging only. Determines if this primitive's commands' bounding spheres are shown. show boolean true 可选 Determines if the polylines in the collection will be shown.

使用示例:

// 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
});

参考:

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

成员(属性)

默认值: false

默认值: Matrix4.IDENTITY

默认值: true

方法

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.

返回值:

Throws:

• DeveloperError : This object was destroyed, i.e., destroy() was called.

使用示例:

// 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
});

参考:

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

返回值:

参考:

• PolylineCollection#get

Throws:

• DeveloperError : This object was destroyed, i.e., destroy() was called.

使用示例:

polylines = polylines && polylines.destroy();

参考:

• PolylineCollection#isDestroyed

Performance:

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

返回值:

Throws:

• DeveloperError : This object was destroyed, i.e., destroy() was called.

使用示例:

// 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;
}

参考:

• PolylineCollection#length

返回值:

参考:

• 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.

返回值:

Throws:

• DeveloperError : This object was destroyed, i.e., destroy() was called.

使用示例:

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

参考:

• 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 : This object was destroyed, i.e., destroy() was called.

使用示例:

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

参考:

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

Throws:

• RuntimeError : Vertex texture fetch support is required to render primitives with per-instance attributes. The maximum number of vertex texture image units must be greater than zero.