# QuaternionSpline

#### new Cesium.QuaternionSpline(options)
Core/QuaternionSpline.js 94

  A spline that uses spherical quadrangle (squad) interpolation to create a quaternion curve. The generated curve is in the class C1.

  Name | Type | Description
  --- | --- | ---
  `options` | Object | Object with the following properties:
  Name | Type | Description
  --- | --- | ---
  `times` | Array.<Number> | An array of strictly increasing, unit-less, floating-point times at each point. The values are in no way connected to the clock time. They are the parameterization for the curve.
  `points` | Array.<Quaternion> | The array of `Quaternion` control points.
  `firstInnerQuadrangle` | Quaternion | optional The inner quadrangle of the curve at the first control point. If the inner quadrangle is not given, it will be estimated.
  `lastInnerQuadrangle` | Quaternion | optional The inner quadrangle of the curve at the last control point. If the inner quadrangle is not given, it will be estimated.

  ##### Throws:

  - DeveloperError : points.length must be greater than or equal to 2.
  - DeveloperError : times.length must be equal to points.length.

  ##### See:

  - HermiteSpline
  - CatmullRomSpline
  - LinearSpline

### Members

#### readonlyinnerQuadrangles : Array.<Quaternion>
Core/QuaternionSpline.js 161

  An array of `Quaternion` inner quadrangles for the control points.

#### readonlypoints : Array.<Quaternion>
Core/QuaternionSpline.js 147

  An array of `Quaternion` control points.

#### readonlytimes : Array.<Number>
Core/QuaternionSpline.js 133

  An array of times for the control points.

### Methods

#### evaluate(time, result) → Quaternion
Core/QuaternionSpline.js 193

  Evaluates the curve at a given time.

  Name | Type | Description
  --- | --- | ---
  `time` | Number | The time at which to evaluate the curve.
  `result` | Quaternion | optional The object onto which to store the result.

  ##### Returns:

  The modified result parameter or a new instance of the point on the curve at the given time.

  ##### Throws:

  - DeveloperError : time must be in the range `[t0, tn]`, where `t0` is the first element in the array `times` and `tn` is the last element in the array `times`.

#### findTimeInterval(time) → Number
Core/QuaternionSpline.js 180

  Finds an index `i` in `times` such that the parameter `time` is in the interval `[times[i], times[i + 1]]`.

  Name | Type | Description
  --- | --- | ---
  `time` | Number | The time.

  ##### Returns:

  The index for the element at the start of the interval.

  ##### Throws:

  - DeveloperError : time must be in the range `[t0, tn]`, where `t0` is the first element in the array `times` and `tn` is the last element in the array `times`.