KBE3D / KBCore / Cesium / Ellipsoid

类: Ellipsoid

A quadratic surface defined in Cartesian coordinates by the equation <code>(x / a)^2 + (y / b)^2 + (z / c)^2 = 1</code>. Primarily used by Cesium to represent the shape of planetary bodies.

Rather than constructing this object directly, one of the provided constants is normally used.

参数

The radius in the x direction.

参数

The radius in the y direction.

参数

The radius in the z direction.

属性

WGS84

readonly static WGS84: Ellipsoid

An Ellipsoid instance initialized to the WGS84 standard.

---

UNIT_SPHERE

readonly static UNIT_SPHERE: Ellipsoid

An Ellipsoid instance initialized to radii of (1.0, 1.0, 1.0).

---

MOON

readonly static MOON: Ellipsoid

An Ellipsoid instance initialized to a sphere with the lunar radius.

---

MARS

readonly static MARS: Ellipsoid

An Ellipsoid instance initialized to a sphere with the mean radii of Mars. Source: https://epsg.io/104905

---

default

static default: Ellipsoid

The default ellipsoid used when not otherwise specified.

示例

Cesium.Ellipsoid.default = Cesium.Ellipsoid.MOON;

// Apollo 11 landing site
const position = Cesium.Cartesian3.fromRadians(
  0.67416,
  23.47315,
);

---

packedLength

static packedLength: number

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

---

radii

readonly radii: Cartesian3

Gets the radii of the ellipsoid.

---

radiiSquared

readonly radiiSquared: Cartesian3

Gets the squared radii of the ellipsoid.

---

radiiToTheFourth

readonly radiiToTheFourth: Cartesian3

Gets the radii of the ellipsoid raise to the fourth power.

---

oneOverRadii

readonly oneOverRadii: Cartesian3

Gets one over the radii of the ellipsoid.

---

oneOverRadiiSquared

readonly oneOverRadiiSquared: Cartesian3

Gets one over the squared radii of the ellipsoid.

---

minimumRadius

readonly minimumRadius: number

Gets the minimum radius of the ellipsoid.

---

maximumRadius

readonly maximumRadius: number

Gets the maximum radius of the ellipsoid.

方法

clone()

static clone(ellipsoid: Ellipsoid, result?: Ellipsoid): Ellipsoid

Duplicates an Ellipsoid instance.

参数

ellipsoid

Ellipsoid

The ellipsoid to duplicate.

result?

Ellipsoid

The object onto which to store the result, or undefined if a new instance should be created.

返回

Ellipsoid

The cloned Ellipsoid. (Returns undefined if ellipsoid is undefined)

---

fromCartesian3()

static fromCartesian3(cartesian?: Cartesian3, result?: Ellipsoid): Ellipsoid

Computes an Ellipsoid from a Cartesian specifying the radii in x, y, and z directions.

参数

cartesian?

Cartesian3

The ellipsoid's radius in the x, y, and z directions.

result?

Ellipsoid

The object onto which to store the result, or undefined if a new instance should be created.

返回

Ellipsoid

A new Ellipsoid instance.

---

pack()

static pack(value: Ellipsoid, array: number[], startingIndex?: number): number[]

Stores the provided instance into the provided array.

参数

value

Ellipsoid

The value to pack.

array

number[]

The array to pack into.

startingIndex?

number

The index into the array at which to start packing the elements.

返回

number[]

The array that was packed into

---

unpack()

static unpack(array: number[], startingIndex?: number, result?: Ellipsoid): Ellipsoid

Retrieves an instance from a packed array.

参数

array

number[]

The packed array.

startingIndex?

number

The starting index of the element to be unpacked.

result?

Ellipsoid

The object into which to store the result.

返回

Ellipsoid

The modified result parameter or a new Ellipsoid instance if one was not provided.

---

clone()

clone(result?: Ellipsoid): Ellipsoid

Duplicates an Ellipsoid instance.

参数

result?

Ellipsoid

The object onto which to store the result, or undefined if a new instance should be created.

返回

Ellipsoid

The cloned Ellipsoid.

---

geocentricSurfaceNormal()

geocentricSurfaceNormal(cartesian: Cartesian3, result?: Cartesian3): Cartesian3

Computes the unit vector directed from the center of this ellipsoid toward the provided Cartesian position.

参数

cartesian

Cartesian3

The Cartesian for which to to determine the geocentric normal.

result?

Cartesian3

The object onto which to store the result.

返回

Cartesian3

The modified result parameter or a new Cartesian3 instance if none was provided.

---

geodeticSurfaceNormalCartographic()

geodeticSurfaceNormalCartographic(cartographic: Cartographic, result?: Cartesian3): Cartesian3

Computes the normal of the plane tangent to the surface of the ellipsoid at the provided position.

参数

cartographic

Cartographic

The cartographic position for which to to determine the geodetic normal.

result?

Cartesian3

The object onto which to store the result.

返回

Cartesian3

The modified result parameter or a new Cartesian3 instance if none was provided.

---

geodeticSurfaceNormal()

geodeticSurfaceNormal(cartesian: Cartesian3, result?: Cartesian3): Cartesian3

Computes the normal of the plane tangent to the surface of the ellipsoid at the provided position.

参数

cartesian

Cartesian3

The Cartesian position for which to to determine the surface normal.

result?

Cartesian3

The object onto which to store the result.

返回

Cartesian3

The modified result parameter or a new Cartesian3 instance if none was provided, or undefined if a normal cannot be found.

---

cartographicToCartesian()

cartographicToCartesian(cartographic: Cartographic, result?: Cartesian3): Cartesian3

Converts the provided cartographic to Cartesian representation.

参数

cartographic

Cartographic

The cartographic position.

result?

Cartesian3

The object onto which to store the result.

返回

Cartesian3

The modified result parameter or a new Cartesian3 instance if none was provided.

示例

//Create a Cartographic and determine it's Cartesian representation on a WGS84 ellipsoid.
const position = new Cesium.Cartographic(Cesium.Math.toRadians(21), Cesium.Math.toRadians(78), 5000);
const cartesianPosition = Cesium.Ellipsoid.WGS84.cartographicToCartesian(position);

---

cartographicArrayToCartesianArray()

cartographicArrayToCartesianArray(cartographics: Cartographic[], result?: Cartesian3[]): Cartesian3[]

Converts the provided array of cartographics to an array of Cartesians.

参数

cartographics

Cartographic[]

An array of cartographic positions.

result?

Cartesian3[]

The object onto which to store the result.

返回

Cartesian3[]

The modified result parameter or a new Array instance if none was provided.

示例

//Convert an array of Cartographics and determine their Cartesian representation on a WGS84 ellipsoid.
const positions = [new Cesium.Cartographic(Cesium.Math.toRadians(21), Cesium.Math.toRadians(78), 0),
                 new Cesium.Cartographic(Cesium.Math.toRadians(21.321), Cesium.Math.toRadians(78.123), 100),
                 new Cesium.Cartographic(Cesium.Math.toRadians(21.645), Cesium.Math.toRadians(78.456), 250)];
const cartesianPositions = Cesium.Ellipsoid.WGS84.cartographicArrayToCartesianArray(positions);

---

cartesianToCartographic()

cartesianToCartographic(cartesian: Cartesian3, result?: Cartographic): Cartographic

Converts the provided cartesian to cartographic representation. The cartesian is undefined at the center of the ellipsoid.

参数

cartesian

Cartesian3

The Cartesian position to convert to cartographic representation.

result?

Cartographic

The object onto which to store the result.

返回

Cartographic

The modified result parameter, new Cartographic instance if none was provided, or undefined if the cartesian is at the center of the ellipsoid.

示例

//Create a Cartesian and determine it's Cartographic representation on a WGS84 ellipsoid.
const position = new Cesium.Cartesian3(17832.12, 83234.52, 952313.73);
const cartographicPosition = Cesium.Ellipsoid.WGS84.cartesianToCartographic(position);

---

cartesianArrayToCartographicArray()

cartesianArrayToCartographicArray(cartesians: Cartesian3[], result?: Cartographic[]): Cartographic[]

Converts the provided array of cartesians to an array of cartographics.

参数

cartesians

Cartesian3[]

An array of Cartesian positions.

result?

Cartographic[]

The object onto which to store the result.

返回

Cartographic[]

The modified result parameter or a new Array instance if none was provided.

示例

//Create an array of Cartesians and determine their Cartographic representation on a WGS84 ellipsoid.
const positions = [new Cesium.Cartesian3(17832.12, 83234.52, 952313.73),
                 new Cesium.Cartesian3(17832.13, 83234.53, 952313.73),
                 new Cesium.Cartesian3(17832.14, 83234.54, 952313.73)]
const cartographicPositions = Cesium.Ellipsoid.WGS84.cartesianArrayToCartographicArray(positions);

---

scaleToGeodeticSurface()

scaleToGeodeticSurface(cartesian: Cartesian3, result?: Cartesian3): Cartesian3

Scales the provided Cartesian position along the geodetic surface normal so that it is on the surface of this ellipsoid. If the position is at the center of the ellipsoid, this function returns undefined.

参数

cartesian

Cartesian3

The Cartesian position to scale.

result?

Cartesian3

The object onto which to store the result.

返回

Cartesian3

The modified result parameter, a new Cartesian3 instance if none was provided, or undefined if the position is at the center.

---

scaleToGeocentricSurface()

scaleToGeocentricSurface(cartesian: Cartesian3, result?: Cartesian3): Cartesian3

Scales the provided Cartesian position along the geocentric surface normal so that it is on the surface of this ellipsoid.

参数

cartesian

Cartesian3

The Cartesian position to scale.

result?

Cartesian3

The object onto which to store the result.

返回

Cartesian3

The modified result parameter or a new Cartesian3 instance if none was provided.

---

transformPositionToScaledSpace()

transformPositionToScaledSpace(position: Cartesian3, result?: Cartesian3): Cartesian3

Transforms a Cartesian X, Y, Z position to the ellipsoid-scaled space by multiplying its components by the result of Ellipsoid#oneOverRadii.

参数

position

Cartesian3

The position to transform.

result?

Cartesian3

The position to which to copy the result, or undefined to create and return a new instance.

返回

Cartesian3

The position expressed in the scaled space. The returned instance is the one passed as the result parameter if it is not undefined, or a new instance of it is.

---

transformPositionFromScaledSpace()

transformPositionFromScaledSpace(position: Cartesian3, result?: Cartesian3): Cartesian3

Transforms a Cartesian X, Y, Z position from the ellipsoid-scaled space by multiplying its components by the result of Ellipsoid#radii.

参数

position

Cartesian3

The position to transform.

result?

Cartesian3

The position to which to copy the result, or undefined to create and return a new instance.

返回

Cartesian3

The position expressed in the unscaled space. The returned instance is the one passed as the result parameter if it is not undefined, or a new instance of it is.

---

equals()

equals(right?: Ellipsoid): boolean

Compares this Ellipsoid against the provided Ellipsoid componentwise and returns <code>true</code> if they are equal, <code>false</code> otherwise.

参数

right?

Ellipsoid

The other Ellipsoid.

返回

boolean

true if they are equal, false otherwise.

---

toString()

toString(): string

Creates a string representing this Ellipsoid in the format '(radii.x, radii.y, radii.z)'.

返回

string

A string representing this ellipsoid in the format '(radii.x, radii.y, radii.z)'.

---

getSurfaceNormalIntersectionWithZAxis()

getSurfaceNormalIntersectionWithZAxis(position: Cartesian3, buffer?: number, result?: Cartesian3): Cartesian3 | undefined

Computes a point which is the intersection of the surface normal with the z-axis.

参数

position

Cartesian3

the position. must be on the surface of the ellipsoid.

buffer?

number

A buffer to subtract from the ellipsoid size when checking if the point is inside the ellipsoid. In earth case, with common earth datums, there is no need for this buffer since the intersection point is always (relatively) very close to the center. In WGS84 datum, intersection point is at max z = +-42841.31151331382 (0.673% of z-axis). Intersection point could be outside the ellipsoid if the ratio of MajorAxis / AxisOfRotation is bigger than the square root of 2

result?

Cartesian3

The cartesian to which to copy the result, or undefined to create and return a new instance.

返回

Cartesian3 | undefined

the intersection point if it's inside the ellipsoid, undefined otherwise

---

getLocalCurvature()

getLocalCurvature(surfacePosition: Cartesian3, result?: Cartesian2): Cartesian2

Computes the ellipsoid curvatures at a given position on the surface.

参数

surfacePosition

Cartesian3

The position on the ellipsoid surface where curvatures will be calculated.

result?

Cartesian2

The cartesian to which to copy the result, or undefined to create and return a new instance.

返回

Cartesian2

The local curvature of the ellipsoid surface at the provided position, in east and north directions.

---

surfaceArea()

surfaceArea(rectangle: Rectangle): number

Computes an approximation of the surface area of a rectangle on the surface of an ellipsoid using Gauss-Legendre 10th order quadrature.

参数

rectangle

Rectangle

The rectangle used for computing the surface area.

返回

number

The approximate area of the rectangle on the surface of this ellipsoid.

构造函数

构造函数

new Ellipsoid(x?: number, y?: number, z?: number): Ellipsoid

参数

x?

number

y?

number

z?

number

返回

Ellipsoid