A description of a polygon on the ellipsoid. The polygon is defined by a polygon hierarchy. Polygon geometry can be rendered with both
Primitive
and GroundPrimitive
.
参数名称 | 类型 | 描述信息 | ||||||||||||||||||||||||||||||||||||||||||||||||||||
---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
options |
object |
Object with the following properties:
|
- PolygonGeometry#createGeometry
- PolygonGeometry#fromPositions
使用示例:
// 1. create a polygon from points
const polygon = new Cesium.PolygonGeometry({
polygonHierarchy : new Cesium.PolygonHierarchy(
Cesium.Cartesian3.fromDegreesArray([
-72.0, 40.0,
-70.0, 35.0,
-75.0, 30.0,
-70.0, 30.0,
-68.0, 40.0
])
)
});
const geometry = Cesium.PolygonGeometry.createGeometry(polygon);
// 2. create a nested polygon with holes
const polygonWithHole = new Cesium.PolygonGeometry({
polygonHierarchy : new Cesium.PolygonHierarchy(
Cesium.Cartesian3.fromDegreesArray([
-109.0, 30.0,
-95.0, 30.0,
-95.0, 40.0,
-109.0, 40.0
]),
[new Cesium.PolygonHierarchy(
Cesium.Cartesian3.fromDegreesArray([
-107.0, 31.0,
-107.0, 39.0,
-97.0, 39.0,
-97.0, 31.0
]),
[new Cesium.PolygonHierarchy(
Cesium.Cartesian3.fromDegreesArray([
-105.0, 33.0,
-99.0, 33.0,
-99.0, 37.0,
-105.0, 37.0
]),
[new Cesium.PolygonHierarchy(
Cesium.Cartesian3.fromDegreesArray([
-103.0, 34.0,
-101.0, 34.0,
-101.0, 36.0,
-103.0, 36.0
])
)]
)]
)]
)
});
const geometry = Cesium.PolygonGeometry.createGeometry(polygonWithHole);
// 3. create extruded polygon
const extrudedPolygon = new Cesium.PolygonGeometry({
polygonHierarchy : new Cesium.PolygonHierarchy(
Cesium.Cartesian3.fromDegreesArray([
-72.0, 40.0,
-70.0, 35.0,
-75.0, 30.0,
-70.0, 30.0,
-68.0, 40.0
])
),
extrudedHeight: 300000
});
const geometry = Cesium.PolygonGeometry.createGeometry(extrudedPolygon);
Demo:
参考:
成员(属性)
The number of elements used to pack the object into an array.
方法
static Cesium.PolygonGeometry.computeRectangleFromPositions(positions, ellipsoid, arcType, result) → Rectangle
Computes a rectangle which encloses the polygon defined by the list of positions, including cases over the international date line and the poles.
参数名称 | 类型 | 默认值 | 描述信息 |
---|---|---|---|
positions |
Array.<Cartesian3> | A linear ring defining the outer boundary of the polygon. | |
ellipsoid |
Ellipsoid |
Ellipsoid.default
|
可选 The ellipsoid to be used as a reference. |
arcType |
ArcType |
ArcType.GEODESIC
|
可选
The type of line the polygon edges must follow. Valid options are ArcType.GEODESIC and ArcType.RHUMB . |
result |
Rectangle | 可选 An object in which to store the result. |
返回值:
The result rectangle
static Cesium.PolygonGeometry.createGeometry(polygonGeometry) → Geometry|undefined
Computes the geometric representation of a polygon, including its vertices, indices, and a bounding sphere.
参数名称 | 类型 | 描述信息 |
---|---|---|
polygonGeometry |
PolygonGeometry | A description of the polygon. |
返回值:
The computed vertices and indices.
static Cesium.PolygonGeometry.fromPositions(options) → PolygonGeometry
A description of a polygon from an array of positions. Polygon geometry can be rendered with both
Primitive
and GroundPrimitive
.
参数名称 | 类型 | 描述信息 | ||||||||||||||||||||||||||||||||||||||||||||||||||||
---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
options |
object |
Object with the following properties:
|
返回值:
- PolygonGeometry#createGeometry
使用示例:
// create a polygon from points
const polygon = Cesium.PolygonGeometry.fromPositions({
positions : Cesium.Cartesian3.fromDegreesArray([
-72.0, 40.0,
-70.0, 35.0,
-75.0, 30.0,
-70.0, 30.0,
-68.0, 40.0
])
});
const geometry = Cesium.PolygonGeometry.createGeometry(polygon);
参考:
Stores the provided instance into the provided array.
参数名称 | 类型 | 默认值 | 描述信息 |
---|---|---|---|
value |
PolygonGeometry | The value to pack. | |
array |
Array.<number> | The array to pack into. | |
startingIndex |
number |
0
|
可选 The index into the array at which to start packing the elements. |
返回值:
The array that was packed into
Retrieves an instance from a packed array.
参数名称 | 类型 | 默认值 | 描述信息 |
---|---|---|---|
array |
Array.<number> | The packed array. | |
startingIndex |
number |
0
|
可选 The starting index of the element to be unpacked. |
result |
PolygonGeometry | 可选 The object into which to store the result. |