Curve

A curve is a collection of keys (time/value pairs). The shape of the curve is defined by its type that specifies an interpolation scheme for the keys.

const curve = new pc.Curve([
    0, 0,        // At 0 time, value of 0
    0.33, 2,     // At 0.33 time, value of 2
    0.66, 2.6,   // At 0.66 time, value of 2.6
    1, 3         // At 1 time, value of 3
]);

Summary

Properties

length	Get the number of keys in the curve.
tension	Controls how CURVE_SPLINE tangents are calculated.
type	The curve interpolation scheme.

Methods

add	Add a new key to the curve.
clone	Returns a clone of the specified curve object.
get	Return a specific key.
sort	Sort keys by time.
value	Returns the interpolated value of the curve at specified time.

Details

Constructor

Curve([data]) 

Creates a new Curve instance.

const curve = new pc.Curve([
    0, 0,        // At 0 time, value of 0
    0.33, 2,     // At 0.33 time, value of 2
    0.66, 2.6,   // At 0.66 time, value of 2.6
    1, 3         // At 1 time, value of 3
]);

Parameters

data

number[]

An array of keys (pairs of numbers with the time first and value second).

Properties

numberlength 

Get the number of keys in the curve.

numbertension 

Controls how CURVE_SPLINE tangents are calculated. Valid range is between 0 and 1 where 0 results in a non-smooth curve (equivalent to linear interpolation) and 1 results in a very smooth curve. Use 0.5 for a Catmull-rom spline.

numbertype 

The curve interpolation scheme. Can be:

Defaults to CURVE_SMOOTHSTEP.