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CatmullRomSpline

CatmullRomSpline

new

A Catmull-Rom spline is a cubic spline where the tangent at control points, except the first and last, are computed using the previous and next control points. Catmull-Rom splines are in the class C1.

Parameters:
Name Type Argument Description
options.times Array The array of control point times.
options.points Array The array of control points.
options.firstTangent Cartesian3 <optional>
 The tangent of the curve at the first control point. If the tangent is not given, it will be estimated.
options.lastTangent Cartesian3 <optional>
 The tangent of the curve at the last control point. If the tangent is not given, it will be estimated.
Throws:
Example
// spline above the earth from Philadelphia to Los Angeles
var spline = new CatmullRomSpline({
    times : [ 0.0, 1.5, 3.0, 4.5, 6.0 ],
    points : [
        new Cartesian3(1235398.0, -4810983.0, 4146266.0),
        new Cartesian3(1372574.0, -5345182.0, 4606657.0),
        new Cartesian3(-757983.0, -5542796.0, 4514323.0),
        new Cartesian3(-2821260.0, -5248423.0, 4021290.0),
        new Cartesian3(-2539788.0, -4724797.0, 3620093.0)
    ]
});
See:
Source:

Members

:DeveloperError

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

<readonly> :Cartesian3

The tangent at the first control point.

<readonly> :Cartesian3

The tangent at the last control point.

<readonly> :Array

An array of Cartesian3 control points.

<readonly> :Array

An array of times for the control points.

Methods

Evaluates the curve at a given time.

Parameters:
Name Type Argument Description
time Number The time at which to evaluate the curve.
result Cartesian3 <optional>
 The object onto which to store the result.
Throws:
  • DeveloperError : time is required.
  • 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.
Returns:
Cartesian3 The modified result parameter or a new instance of the point on the curve at the given time.
Example
// spline above the earth from Philadelphia to Los Angeles
var spline = new CatmullRomSpline({
    times : [ 0.0, 1.5, 3.0, 4.5, 6.0 ],
    points : [
        new Cartesian3(1235398.0, -4810983.0, 4146266.0),
        new Cartesian3(1372574.0, -5345182.0, 4606657.0),
        new Cartesian3(-757983.0, -5542796.0, 4514323.0),
        new Cartesian3(-2821260.0, -5248423.0, 4021290.0),
        new Cartesian3(-2539788.0, -4724797.0, 3620093.0)
    ]
});

// some position above Los Angeles
var position = spline.evaluate(5.0);