KBE3D / KBCore / Cesium / CatmullRomSpline

类: CatmullRomSpline

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.

示例

// spline above the earth from Philadelphia to Los Angeles
const spline = new Cesium.CatmullRomSpline({
    times : [ 0.0, 1.5, 3.0, 4.5, 6.0 ],
    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[i]);         // equal to positions[i]
const p1 = spline.evaluate(times[i] + delta); // interpolated value when delta < times[i + 1] - times[i]

参数

Object with the following properties:

参数

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.

参数

The array of Cartesian3 control points.

参数

The tangent of the curve at the first control point. If the tangent is not given, it will be estimated.

参数

The tangent of the curve at the last control point. If the tangent is not given, it will be estimated.

属性

times

readonly times: number[]

An array of times for the control points.

---

points

readonly points: Cartesian3[]

An array of Cartesian3 control points.

---

firstTangent

readonly firstTangent: Cartesian3

The tangent at the first control point.

---

lastTangent

readonly lastTangent: Cartesian3

The tangent at the last control point.

方法

findTimeInterval()

findTimeInterval(time: number): number

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

参数

time

number

The time.

返回

number

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

---

wrapTime()

wrapTime(time: number): number

Wraps the given time to the period covered by the spline.

参数

time

number

The time.

返回

number

The time, wrapped around to the updated animation.

---

clampTime()

clampTime(time: number): number

Clamps the given time to the period covered by the spline.

参数

time

number

The time.

返回

number

The time, clamped to the animation period.

---

evaluate()

evaluate(time: number, result?: Cartesian3): Cartesian3

Evaluates the curve at a given time.

参数

time

number

The time at which to evaluate the curve.

result?

Cartesian3

The object onto which to store the result.

返回

Cartesian3

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

构造函数

构造函数

new CatmullRomSpline(options: { times: number[]; points: Cartesian3[]; firstTangent?: Cartesian3; lastTangent?: Cartesian3; }): CatmullRomSpline

参数

options

times

number[]

points

Cartesian3[]

firstTangent?

Cartesian3

lastTangent?

Cartesian3

返回

CatmullRomSpline