Transforms

Contains functions for transforming positions to various reference frames.

方法

static Cesium.Transforms.computeFixedToIcrfMatrix(date, result)Matrix3|undefined

Computes a rotation matrix to transform a point or vector from the Earth-Fixed frame axes (ITRF) to the International Celestial Reference Frame (GCRF/ICRF) inertial frame axes at a given time. This function may return undefined if the data necessary to do the transformation is not yet loaded.
参数名称 类型 描述信息
date JulianDate The time at which to compute the rotation matrix.
result Matrix3 可选 The object onto which to store the result. If this parameter is not specified, a new instance is created and returned.
返回值:
The rotation matrix, or undefined if the data necessary to do the transformation is not yet loaded.
使用示例:
// Transform a point from the Fixed axes to the ICRF axes.
const now = Cesium.JulianDate.now();
const pointInFixed = Cesium.Cartesian3.fromDegrees(0.0, 0.0);
const fixedToIcrf = Cesium.Transforms.computeFixedToIcrfMatrix(now);
let pointInInertial = new Cesium.Cartesian3();
if (Cesium.defined(fixedToIcrf)) {
    pointInInertial = Cesium.Matrix3.multiplyByVector(fixedToIcrf, pointInFixed, pointInInertial);
}
参考:

static Cesium.Transforms.computeIcrfToCentralBodyFixedMatrix(date, result)Matrix3|undefined

The default function to compute a rotation matrix to transform a point or vector from the International Celestial Reference Frame (GCRF/ICRF) inertial frame axes to the central body, typically Earth, fixed frame axis at a given time for use in lighting and transformation from inertial reference frames. This function may return undefined if the data necessary to do the transformation is not yet loaded.
参数名称 类型 描述信息
date JulianDate The time at which to compute the rotation matrix.
result Matrix3 可选 The object onto which to store the result. If this parameter is not specified, a new instance is created and returned.
返回值:
The rotation matrix, or undefined if the data necessary to do the transformation is not yet loaded.
使用示例:
// Set the default ICRF to fixed transformation to that of the Moon.
Cesium.Transforms.computeIcrfToCentralBodyFixedMatrix = Cesium.Transforms.computeIcrfToMoonFixedMatrix;
参考:

static Cesium.Transforms.computeIcrfToFixedMatrix(date, result)Matrix3|undefined

Computes a rotation matrix to transform a point or vector from the International Celestial Reference Frame (GCRF/ICRF) inertial frame axes to the Earth-Fixed frame axes (ITRF) at a given time. This function may return undefined if the data necessary to do the transformation is not yet loaded.
参数名称 类型 描述信息
date JulianDate The time at which to compute the rotation matrix.
result Matrix3 可选 The object onto which to store the result. If this parameter is not specified, a new instance is created and returned.
返回值:
The rotation matrix, or undefined if the data necessary to do the transformation is not yet loaded.
使用示例:
scene.postUpdate.addEventListener(function(scene, time) {
  // View in ICRF.
  const icrfToFixed = Cesium.Transforms.computeIcrfToFixedMatrix(time);
  if (Cesium.defined(icrfToFixed)) {
    const offset = Cesium.Cartesian3.clone(camera.position);
    const transform = Cesium.Matrix4.fromRotationTranslation(icrfToFixed);
    camera.lookAtTransform(transform, offset);
  }
});
参考:

static Cesium.Transforms.computeIcrfToMoonFixedMatrix(date, result)Matrix3

Computes a rotation matrix to transform a point or vector from the International Celestial Reference Frame (GCRF/ICRF) inertial frame axes to the Moon-Fixed frame axes at a given time.
参数名称 类型 描述信息
date JulianDate The time at which to compute the rotation matrix.
result Matrix3 可选 The object onto which to store the result. If this parameter is not specified, a new instance is created and returned.
返回值:
The rotation matrix.
使用示例:
// Set the default ICRF to fixed transformation to that of the Moon.
Cesium.Transforms.computeIcrfToCentralBodyFixedMatrix = Cesium.Transforms.computeIcrfToMoonFixedMatrix;

static Cesium.Transforms.computeMoonFixedToIcrfMatrix(date, result)Matrix3

Computes a rotation matrix to transform a point or vector from the Moon-Fixed frame axes to the International Celestial Reference Frame (GCRF/ICRF) inertial frame axes at a given time.
参数名称 类型 描述信息
date JulianDate The time at which to compute the rotation matrix.
result Matrix3 可选 The object onto which to store the result. If this parameter is not specified, a new instance is created and returned.
返回值:
The rotation matrix.
使用示例:
// Transform a point from the Fixed axes to the ICRF axes.
const now = Cesium.JulianDate.now();
const pointInFixed = Cesium.Cartesian3.fromDegrees(0.0, 0.0);
const fixedToIcrf = Cesium.Transforms.computeMoonFixedToIcrfMatrix(now);
let pointInInertial = new Cesium.Cartesian3();
if (Cesium.defined(fixedToIcrf)) {
    pointInInertial = Cesium.Matrix3.multiplyByVector(fixedToIcrf, pointInFixed, pointInInertial);
}

static Cesium.Transforms.computeTemeToPseudoFixedMatrix(date, result)Matrix3

Computes a rotation matrix to transform a point or vector from True Equator Mean Equinox (TEME) axes to the pseudo-fixed axes at a given time. This method treats the UT1 time standard as equivalent to UTC.
参数名称 类型 描述信息
date JulianDate The time at which to compute the rotation matrix.
result Matrix3 可选 The object onto which to store the result.
返回值:
The modified result parameter or a new Matrix3 instance if none was provided.
使用示例:
//Set the view to the inertial frame.
scene.postUpdate.addEventListener(function(scene, time) {
   const now = Cesium.JulianDate.now();
   const offset = Cesium.Matrix4.multiplyByPoint(camera.transform, camera.position, new Cesium.Cartesian3());
   const transform = Cesium.Matrix4.fromRotationTranslation(Cesium.Transforms.computeTemeToPseudoFixedMatrix(now));
   const inverseTransform = Cesium.Matrix4.inverseTransformation(transform, new Cesium.Matrix4());
   Cesium.Matrix4.multiplyByPoint(inverseTransform, offset, offset);
   camera.lookAtTransform(transform, offset);
});

static Cesium.Transforms.eastNorthUpToFixedFrame(origin, ellipsoid, result)Matrix4

Computes a 4x4 transformation matrix from a reference frame with an east-north-up axes centered at the provided origin to the provided ellipsoid's fixed reference frame. The local axes are defined as:
  • The x axis points in the local east direction.
  • The y axis points in the local north direction.
  • The z axis points in the direction of the ellipsoid surface normal which passes through the position.
参数名称 类型 默认值 描述信息
origin Cartesian3 The center point of the local reference frame.
ellipsoid Ellipsoid Ellipsoid.default 可选 The ellipsoid whose fixed frame is used in the transformation.
result Matrix4 可选 The object onto which to store the result.
返回值:
The modified result parameter or a new Matrix4 instance if none was provided.
使用示例:
// Get the transform from local east-north-up at cartographic (0.0, 0.0) to Earth's fixed frame.
const center = Cesium.Cartesian3.fromDegrees(0.0, 0.0);
const transform = Cesium.Transforms.eastNorthUpToFixedFrame(center);

static Cesium.Transforms.fixedFrameToHeadingPitchRoll(transform, ellipsoid, fixedFrameTransform, result)HeadingPitchRoll

Computes heading-pitch-roll angles from a transform in a particular reference frame. Heading is the rotation from the local east direction where a positive angle is increasing eastward. Pitch is the rotation from the local east-north plane. Positive pitch angles are above the plane. Negative pitch angles are below the plane. Roll is the first rotation applied about the local east axis.
参数名称 类型 默认值 描述信息
transform Matrix4 The transform
ellipsoid Ellipsoid Ellipsoid.default 可选 The ellipsoid whose fixed frame is used in the transformation.
fixedFrameTransform Transforms.LocalFrameToFixedFrame Transforms.eastNorthUpToFixedFrame 可选 A 4x4 transformation matrix from a reference frame to the provided ellipsoid's fixed reference frame
result HeadingPitchRoll 可选 The object onto which to store the result.
返回值:
The modified result parameter or a new HeadingPitchRoll instance if none was provided.

static Cesium.Transforms.headingPitchRollQuaternion(origin, headingPitchRoll, ellipsoid, fixedFrameTransform, result)Quaternion

Computes a quaternion from a reference frame with axes computed from the heading-pitch-roll angles centered at the provided origin. Heading is the rotation from the local east direction where a positive angle is increasing eastward. Pitch is the rotation from the local east-north plane. Positive pitch angles are above the plane. Negative pitch angles are below the plane. Roll is the first rotation applied about the local east axis.
参数名称 类型 默认值 描述信息
origin Cartesian3 The center point of the local reference frame.
headingPitchRoll HeadingPitchRoll The heading, pitch, and roll.
ellipsoid Ellipsoid Ellipsoid.default 可选 The ellipsoid whose fixed frame is used in the transformation.
fixedFrameTransform Transforms.LocalFrameToFixedFrame Transforms.eastNorthUpToFixedFrame 可选 A 4x4 transformation matrix from a reference frame to the provided ellipsoid's fixed reference frame
result Quaternion 可选 The object onto which to store the result.
返回值:
The modified result parameter or a new Quaternion instance if none was provided.
使用示例:
// Get the quaternion from local heading-pitch-roll at cartographic (0.0, 0.0) to Earth's fixed frame.
const center = Cesium.Cartesian3.fromDegrees(0.0, 0.0);
const heading = -Cesium.Math.PI_OVER_TWO;
const pitch = Cesium.Math.PI_OVER_FOUR;
const roll = 0.0;
const hpr = new HeadingPitchRoll(heading, pitch, roll);
const quaternion = Cesium.Transforms.headingPitchRollQuaternion(center, hpr);

static Cesium.Transforms.headingPitchRollToFixedFrame(origin, headingPitchRoll, ellipsoid, fixedFrameTransform, result)Matrix4

Computes a 4x4 transformation matrix from a reference frame with axes computed from the heading-pitch-roll angles centered at the provided origin to the provided ellipsoid's fixed reference frame. Heading is the rotation from the local east direction where a positive angle is increasing eastward. Pitch is the rotation from the local east-north plane. Positive pitch angles are above the plane. Negative pitch angles are below the plane. Roll is the first rotation applied about the local east axis.
参数名称 类型 默认值 描述信息
origin Cartesian3 The center point of the local reference frame.
headingPitchRoll HeadingPitchRoll The heading, pitch, and roll.
ellipsoid Ellipsoid Ellipsoid.default 可选 The ellipsoid whose fixed frame is used in the transformation.
fixedFrameTransform Transforms.LocalFrameToFixedFrame Transforms.eastNorthUpToFixedFrame 可选 A 4x4 transformation matrix from a reference frame to the provided ellipsoid's fixed reference frame
result Matrix4 可选 The object onto which to store the result.
返回值:
The modified result parameter or a new Matrix4 instance if none was provided.
使用示例:
// Get the transform from local heading-pitch-roll at cartographic (0.0, 0.0) to Earth's fixed frame.
const center = Cesium.Cartesian3.fromDegrees(0.0, 0.0);
const heading = -Cesium.Math.PI_OVER_TWO;
const pitch = Cesium.Math.PI_OVER_FOUR;
const roll = 0.0;
const hpr = new Cesium.HeadingPitchRoll(heading, pitch, roll);
const transform = Cesium.Transforms.headingPitchRollToFixedFrame(center, hpr);

static Cesium.Transforms.localFrameToFixedFrameGenerator(firstAxis, secondAxis)Transforms.LocalFrameToFixedFrame

Generates a function that computes a 4x4 transformation matrix from a reference frame centered at the provided origin to the provided ellipsoid's fixed reference frame.
参数名称 类型 描述信息
firstAxis string name of the first axis of the local reference frame. Must be 'east', 'north', 'up', 'west', 'south' or 'down'.
secondAxis string name of the second axis of the local reference frame. Must be 'east', 'north', 'up', 'west', 'south' or 'down'.
返回值:
The function that will computes a 4x4 transformation matrix from a reference frame, with first axis and second axis compliant with the parameters,

static Cesium.Transforms.northEastDownToFixedFrame(origin, ellipsoid, result)Matrix4

Computes a 4x4 transformation matrix from a reference frame with an north-east-down axes centered at the provided origin to the provided ellipsoid's fixed reference frame. The local axes are defined as:
  • The x axis points in the local north direction.
  • The y axis points in the local east direction.
  • The z axis points in the opposite direction of the ellipsoid surface normal which passes through the position.
参数名称 类型 默认值 描述信息
origin Cartesian3 The center point of the local reference frame.
ellipsoid Ellipsoid Ellipsoid.default 可选 The ellipsoid whose fixed frame is used in the transformation.
result Matrix4 可选 The object onto which to store the result.
返回值:
The modified result parameter or a new Matrix4 instance if none was provided.
使用示例:
// Get the transform from local north-east-down at cartographic (0.0, 0.0) to Earth's fixed frame.
const center = Cesium.Cartesian3.fromDegrees(0.0, 0.0);
const transform = Cesium.Transforms.northEastDownToFixedFrame(center);

static Cesium.Transforms.northUpEastToFixedFrame(origin, ellipsoid, result)Matrix4

Computes a 4x4 transformation matrix from a reference frame with an north-up-east axes centered at the provided origin to the provided ellipsoid's fixed reference frame. The local axes are defined as:
  • The x axis points in the local north direction.
  • The y axis points in the direction of the ellipsoid surface normal which passes through the position.
  • The z axis points in the local east direction.
参数名称 类型 默认值 描述信息
origin Cartesian3 The center point of the local reference frame.
ellipsoid Ellipsoid Ellipsoid.default 可选 The ellipsoid whose fixed frame is used in the transformation.
result Matrix4 可选 The object onto which to store the result.
返回值:
The modified result parameter or a new Matrix4 instance if none was provided.
使用示例:
// Get the transform from local north-up-east at cartographic (0.0, 0.0) to Earth's fixed frame.
const center = Cesium.Cartesian3.fromDegrees(0.0, 0.0);
const transform = Cesium.Transforms.northUpEastToFixedFrame(center);

static Cesium.Transforms.northWestUpToFixedFrame(origin, ellipsoid, result)Matrix4

Computes a 4x4 transformation matrix from a reference frame with an north-west-up axes centered at the provided origin to the provided ellipsoid's fixed reference frame. The local axes are defined as:
  • The x axis points in the local north direction.
  • The y axis points in the local west direction.
  • The z axis points in the direction of the ellipsoid surface normal which passes through the position.
参数名称 类型 默认值 描述信息
origin Cartesian3 The center point of the local reference frame.
ellipsoid Ellipsoid Ellipsoid.default 可选 The ellipsoid whose fixed frame is used in the transformation.
result Matrix4 可选 The object onto which to store the result.
返回值:
The modified result parameter or a new Matrix4 instance if none was provided.
使用示例:
// Get the transform from local north-West-Up at cartographic (0.0, 0.0) to Earth's fixed frame.
const center = Cesium.Cartesian3.fromDegrees(0.0, 0.0);
const transform = Cesium.Transforms.northWestUpToFixedFrame(center);

static Cesium.Transforms.pointToWindowCoordinates(modelViewProjectionMatrix, viewportTransformation, point, result)Cartesian2

Transform a point from model coordinates to window coordinates.
参数名称 类型 描述信息
modelViewProjectionMatrix Matrix4 The 4x4 model-view-projection matrix.
viewportTransformation Matrix4 The 4x4 viewport transformation.
point Cartesian3 The point to transform.
result Cartesian2 可选 The object onto which to store the result.
返回值:
The modified result parameter or a new Cartesian2 instance if none was provided.

static Cesium.Transforms.preloadIcrfFixed(timeInterval)Promise.<void>

Preloads the data necessary to transform between the ICRF and Fixed axes, in either direction, over a given interval. This function returns a promise that, when resolved, indicates that the preload has completed.
参数名称 类型 描述信息
timeInterval TimeInterval The interval to preload.
返回值:
A promise that, when resolved, indicates that the preload has completed and evaluation of the transformation between the fixed and ICRF axes will no longer return undefined for a time inside the interval.
使用示例:
const interval = new Cesium.TimeInterval(...);
await Cesium.Transforms.preloadIcrfFixed(interval));
// the data is now loaded
参考:

static Cesium.Transforms.rotationMatrixFromPositionVelocity(position, velocity, ellipsoid, result)Matrix3

Transform a position and velocity to a rotation matrix.
参数名称 类型 默认值 描述信息
position Cartesian3 The position to transform.
velocity Cartesian3 The velocity vector to transform.
ellipsoid Ellipsoid Ellipsoid.default 可选 The ellipsoid whose fixed frame is used in the transformation.
result Matrix3 可选 The object onto which to store the result.
返回值:
The modified result parameter or a new Matrix3 instance if none was provided.

定义的类型

Cesium.Transforms.LocalFrameToFixedFrame(origin, ellipsoid, result)Matrix4

Computes a 4x4 transformation matrix from a reference frame centered at the provided origin to the provided ellipsoid's fixed reference frame.
参数名称 类型 默认值 描述信息
origin Cartesian3 The center point of the local reference frame.
ellipsoid Ellipsoid Ellipsoid.default 可选 The ellipsoid whose fixed frame is used in the transformation.
result Matrix4 可选 The object onto which to store the result.
返回值:
The modified result parameter or a new Matrix4 instance if none was provided.