# PolygonGeometry

#### new Cesium.PolygonGeometry(options)
Core/PolygonGeometry.js 650

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`.

Name | Type | Description
--- | --- | ---
`options` | Object | Object with the following properties:
Name | Type | Default | Description
--- | --- | --- | ---
`polygonHierarchy` | PolygonHierarchy |  | A polygon hierarchy that can include holes.
`height` | Number | `0.0` | optional The distance in meters between the polygon and the ellipsoid surface.
`extrudedHeight` | Number |  | optional The distance in meters between the polygon's extruded face and the ellipsoid surface.
`vertexFormat` | VertexFormat | `VertexFormat.DEFAULT` | optional The vertex attributes to be computed.
`indices` | Array.<Number> |  | optional 自定义顶点索引
`st` | Float32Array |  | optional 自定义UV坐标
`stRotation` | Number | `0.0` | optional The rotation of the texture coordinates, in radians. A positive rotation is counter-clockwise.
`ellipsoid` | Ellipsoid | `Ellipsoid.WGS84` | optional The ellipsoid to be used as a reference.
`granularity` | Number | `CesiumMath.RADIANS_PER_DEGREE` | optional The distance, in radians, between each latitude and longitude. Determines the number of positions in the buffer.
`perPositionHeight` | Boolean | `false` | optional Use the height of options.positions for each position instead of using options.height to determine the height.
`closeTop` | Boolean | `true` | optional When false, leaves off the top of an extruded polygon open.
`closeBottom` | Boolean | `true` | optional When false, leaves off the bottom of an extruded polygon open.
`arcType` | ArcType | `ArcType.GEODESIC` | optional The type of line the polygon edges must follow. Valid options are `ArcType.GEODESIC` and `ArcType.RHUMB`.

##### Example:

    // 1. create a polygon from points
    var 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
        ])
      )
    });
    var geometry = Cesium.PolygonGeometry.createGeometry(polygon);

    // 2. create a nested polygon with holes
    var 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
              ])
            )]
          )]
        )]
      )
    });
    var geometry = Cesium.PolygonGeometry.createGeometry(polygonWithHole);

    // 3. create extruded polygon
    var 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
    });
    var geometry = Cesium.PolygonGeometry.createGeometry(extrudedPolygon);

##### Demo:

- Cesium Sandcastle Polygon Demo

##### See:

- PolygonGeometry#createGeometry
- PolygonGeometry#fromPositions

### Members

#### _indices
Core/PolygonGeometry.js 686

feat:2106 河流覆盖物类型 传入自定义顶点indices 传入自定义UV坐标

#### packedLength : Number
Core/PolygonGeometry.js 708

The number of elements used to pack the object into an array.

### Methods

#### static Cesium.PolygonGeometry.computeRectangle(options, result) → Rectangle
Core/PolygonGeometry.js 899

Returns the bounding rectangle given the provided options

Name | Type | Description
--- | --- | ---
`options` | Object | Object with the following properties:
Name | Type | Default | Description
--- | --- | --- | ---
`polygonHierarchy` | PolygonHierarchy |  | A polygon hierarchy that can include holes.
`granularity` | Number | `CesiumMath.RADIANS_PER_DEGREE` | optional The distance, in radians, between each latitude and longitude. Determines the number of positions sampled.
`arcType` | ArcType | `ArcType.GEODESIC` | optional The type of line the polygon edges must follow. Valid options are `ArcType.GEODESIC` and `ArcType.RHUMB`.
`ellipsoid` | Ellipsoid | `Ellipsoid.WGS84` | optional The ellipsoid to be used as a reference.
`result` | Rectangle | optional An object in which to store the result.

##### Returns:

The result rectangle

#### static Cesium.PolygonGeometry.createGeometry(polygonGeometry) → Geometry|undefined
Core/PolygonGeometry.js 925

Computes the geometric representation of a polygon, including its vertices, indices, and a bounding sphere.

Name | Type | Description
--- | --- | ---
`polygonGeometry` | PolygonGeometry | A description of the polygon.

##### Returns:

The computed vertices and indices.

#### static Cesium.PolygonGeometry.fromPositions(options) → PolygonGeometry
Core/PolygonGeometry.js 746

A description of a polygon from an array of positions. Polygon geometry can be rendered with both `Primitive` and `GroundPrimitive`.

Name | Type | Description
--- | --- | ---
`options` | Object | Object with the following properties:
Name | Type | Default | Description
--- | --- | --- | ---
`positions` | Array.<Cartesian3> |  | An array of positions that defined the corner points of the polygon.
`height` | Number | `0.0` | optional The height of the polygon.
`extrudedHeight` | Number |  | optional The height of the polygon extrusion.
`vertexFormat` | VertexFormat | `VertexFormat.DEFAULT` | optional The vertex attributes to be computed.
`indices` | Array.<Number> |  | optional 自定义顶点索引
`st` | Float32Array |  | optional 自定义UV坐标
`stRotation` | Number | `0.0` | optional The rotation of the texture coordinates, in radians. A positive rotation is counter-clockwise.
`ellipsoid` | Ellipsoid | `Ellipsoid.WGS84` | optional The ellipsoid to be used as a reference.
`granularity` | Number | `CesiumMath.RADIANS_PER_DEGREE` | optional The distance, in radians, between each latitude and longitude. Determines the number of positions in the buffer.
`perPositionHeight` | Boolean | `false` | optional Use the height of options.positions for each position instead of using options.height to determine the height.
`closeTop` | Boolean | `true` | optional When false, leaves off the top of an extruded polygon open.
`closeBottom` | Boolean | `true` | optional When false, leaves off the bottom of an extruded polygon open.
`arcType` | ArcType | `ArcType.GEODESIC` | optional The type of line the polygon edges must follow. Valid options are `ArcType.GEODESIC` and `ArcType.RHUMB`.

##### Returns:

##### Example:

    // create a polygon from points
    var 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
      ])
    });
    var geometry = Cesium.PolygonGeometry.createGeometry(polygon);

##### See:

- PolygonGeometry#createGeometry

#### static Cesium.PolygonGeometry.pack(value, array, startingIndex) → Array.<Number>
Core/PolygonGeometry.js 788

Stores the provided instance into the provided array.

Name | Type | Default | Description
--- | --- | --- | ---
`value` | PolygonGeometry |  | The value to pack.
`array` | Array.<Number> |  | The array to pack into.
`startingIndex` | Number | `0` | optional The index into the array at which to start packing the elements.

##### Returns:

The array that was packed into

#### static Cesium.PolygonGeometry.unpack(array, startingIndex, result)
Core/PolygonGeometry.js 835

Retrieves an instance from a packed array.

Name | Type | Default | Description
--- | --- | --- | ---
`array` | Array.<Number> |  | The packed array.
`startingIndex` | Number | `0` | optional The starting index of the element to be unpacked.
`result` | PolygonGeometry |  | optional The object into which to store the result.