EllipseGeometry

new Cesium.EllipseGeometry(options)

A description of an ellipse on an ellipsoid. Ellipse 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:
参数名称 类型 默认值 描述信息
center Cartesian3 The ellipse's center point in the fixed frame.
semiMajorAxis number The length of the ellipse's semi-major axis in meters.
semiMinorAxis number The length of the ellipse's semi-minor axis in meters.
ellipsoid Ellipsoid Ellipsoid.default 可选 The ellipsoid the ellipse will be on.
height number 0.0 可选 The distance in meters between the ellipse and the ellipsoid surface.
extrudedHeight number 可选 The distance in meters between the ellipse's extruded face and the ellipsoid surface.
rotation number 0.0 可选 The angle of rotation counter-clockwise from north.
stRotation number 0.0 可选 The rotation of the texture coordinates counter-clockwise from north.
granularity number CesiumMath.RADIANS_PER_DEGREE 可选 The angular distance between points on the ellipse in radians.
vertexFormat VertexFormat VertexFormat.DEFAULT 可选 The vertex attributes to be computed.
Throws:
  • DeveloperError : semiMajorAxis and semiMinorAxis must be greater than zero.
  • DeveloperError : semiMajorAxis must be greater than or equal to the semiMinorAxis.
  • DeveloperError : granularity must be greater than zero.
使用示例:
// Create an ellipse.
const ellipse = new Cesium.EllipseGeometry({
  center : Cesium.Cartesian3.fromDegrees(-75.59777, 40.03883),
  semiMajorAxis : 500000.0,
  semiMinorAxis : 300000.0,
  rotation : Cesium.Math.toRadians(60.0)
});
const geometry = Cesium.EllipseGeometry.createGeometry(ellipse);
参考:

成员(属性)

static Cesium.EllipseGeometry.packedLength : number

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

方法

static Cesium.EllipseGeometry.computeRectangle(options, result)Rectangle

Computes the bounding rectangle based on the provided options
参数名称 类型 描述信息
options object Object with the following properties:
参数名称 类型 默认值 描述信息
center Cartesian3 The ellipse's center point in the fixed frame.
semiMajorAxis number The length of the ellipse's semi-major axis in meters.
semiMinorAxis number The length of the ellipse's semi-minor axis in meters.
ellipsoid Ellipsoid Ellipsoid.default 可选 The ellipsoid the ellipse will be on.
rotation number 0.0 可选 The angle of rotation counter-clockwise from north.
granularity number CesiumMath.RADIANS_PER_DEGREE 可选 The angular distance between points on the ellipse in radians.
result Rectangle 可选 An object in which to store the result
返回值:
The result rectangle

static Cesium.EllipseGeometry.createGeometry(ellipseGeometry)Geometry|undefined

Computes the geometric representation of a ellipse on an ellipsoid, including its vertices, indices, and a bounding sphere.
参数名称 类型 描述信息
ellipseGeometry EllipseGeometry A description of the ellipse.
返回值:
The computed vertices and indices.

static Cesium.EllipseGeometry.pack(value, array, startingIndex)Array.<number>

Stores the provided instance into the provided array.
参数名称 类型 默认值 描述信息
value EllipseGeometry 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

static Cesium.EllipseGeometry.unpack(array, startingIndex, result)EllipseGeometry

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 EllipseGeometry 可选 The object into which to store the result.
返回值:
The modified result parameter or a new EllipseGeometry instance if one was not provided.