SteppedSpline

new Cesium.SteppedSpline(options)

A spline that is composed of piecewise constants representing a step function.
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.<Number> | Array.<Cartesian3> | Array.<Quaternion> The array of control points.
Throws:
Example:
const times = [ 0.0, 1.5, 3.0, 4.5, 6.0 ];
const spline = new Cesium.SteppedSpline({
    times : times,
    points : [
        new Cesium.Cartesian3(1235398.0, -4810983.0, 4146266.0),
        new Cesium.Cartesian3(1372574.0, -5345182.0, 4606657.0),
        new Cesium.Cartesian3(-757983.0, -5542796.0, 4514323.0),
        new Cesium.Cartesian3(-2821260.0, -5248423.0, 4021290.0),
        new Cesium.Cartesian3(-2539788.0, -4724797.0, 3620093.0)
    ]
});

const p0 = spline.evaluate(times[0]);
See:

Members

readonly points : Array.<Number>|Array.<Cartesian3>|Array.<Quaternion>

An array of control points.

readonly times : Array.<Number>

An array of times for the control points.

Methods

clampTime(time)Number

Clamps the given time to the period covered by the spline.
Name Type Description
time Number The time.
Returns:
The time, clamped to the animation period.

evaluate(time, result)Number|Cartesian3|Quaternion

Evaluates the curve at a given time.
Name Type Description
time Number The time at which to evaluate the curve.
result Cartesian3 | 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, startIndex)Number

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.
startIndex Number The index from which to start the search.
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.

wrapTime(time)Number

Wraps the given time to the period covered by the spline.
Name Type Description
time Number The time.
Returns:
The time, wrapped around to the updated animation.
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