GeometryInstance - CesiumJS API 文档

new Cesium.GeometryInstance(options)

Geometry instancing allows one Geometry object to be positions in several different locations and colored uniquely. For example, one BoxGeometry can be instanced several times, each with a different modelMatrix to change 其位置、旋转和规模.

Name Type Description

options

object

下列属性的对象 :

Name	Type	Default	Description
`geometry`	Geometry \| GeometryFactory		几何为例.
`modelMatrix`	Matrix4	`Matrix4.IDENTITY`	optional The model matrix that transforms to transform the geometry from model to world coordinates.
`id`	object		optional A user-defined object to return when the instance is picked with `Scene#pick` or get/set per-instance attributes with `Primitive#getGeometryInstanceAttributes`.
`attributes`	object		optional 如下文示例所示的显示或颜色属性那样的偶联属性.

Example:

// Create geometry for a box, and two instances that refer to it.
// One instance positions the box on the bottom and colored aqua.
// The other instance positions the box on the top and color white.
const geometry = Cesium.BoxGeometry.fromDimensions({
  vertexFormat : Cesium.VertexFormat.POSITION_AND_NORMAL,
  dimensions : new Cesium.Cartesian3(1000000.0, 1000000.0, 500000.0)
});
const instanceBottom = new Cesium.GeometryInstance({
  geometry : geometry,
  modelMatrix : Cesium.Matrix4.multiplyByTranslation(Cesium.Transforms.eastNorthUpToFixedFrame(
    Cesium.Cartesian3.fromDegrees(-75.59777, 40.03883)), new Cesium.Cartesian3(0.0, 0.0, 1000000.0), new Cesium.Matrix4()),
  attributes : {
    color : Cesium.ColorGeometryInstanceAttribute.fromColor(Cesium.Color.AQUA)
  },
  id : 'bottom'
});
const instanceTop = new Cesium.GeometryInstance({
  geometry : geometry,
  modelMatrix : Cesium.Matrix4.multiplyByTranslation(Cesium.Transforms.eastNorthUpToFixedFrame(
    Cesium.Cartesian3.fromDegrees(-75.59777, 40.03883)), new Cesium.Cartesian3(0.0, 0.0, 3000000.0), new Cesium.Matrix4()),
  attributes : {
    color : Cesium.ColorGeometryInstanceAttribute.fromColor(Cesium.Color.AQUA)
  },
  id : 'top'
});

See:

Geometry

Members

attributes : object

Per-instance attributes like ColorGeometryInstanceAttribute or ShowGeometryInstanceAttribute. Geometry attributes varying per vertex; these attributes are constant for the entire instance.

Default Value: {}

geometry : Geometry

示现几何.

id : object|undefined

选择实例时返回用户定义的对象,或者用于获取/设置每事件属性.

Default Value: undefined

See:

modelMatrix : Matrix4

将几何学从模型转换成世界坐标的4x4变换矩阵. 当这是身份矩阵时,几何图画在世界坐标, i.e . 地球的 WGS84 坐标. 本地参考框架可以通过提供不同的变换矩阵来使用, 如返回的变换矩阵 by Transforms.eastNorthUpToFixedFrame.

Default Value: Matrix4.IDENTITY