Keyframe.inTangent

Description

Describes the tangent when approaching this point from the previous point in the curve.

The angle needs to be expressed in radians.

The tangent is really just the gradient of the slope, as in "change in y / change in x"

另请参阅：outTangent。

using UnityEngine;

public class KeyFrameTangentExample : MonoBehaviour
{
    AnimationCurve  animCurve = null;


    void Start()
    {
        Keyframe[] ks = new Keyframe[3];

        ks[0] = new Keyframe(0, 0);
        ks[0].inTangent = 1.5708f;          // 90 degrees up

        ks[1] = new Keyframe(4, 0);
        ks[1].inTangent = 0;                // straight

        ks[2] = new Keyframe(6, 0);
        ks[2].inTangent = -1.5708f;         // 90 degrees down

        animCurve = new AnimationCurve(ks);
    }

    void Update()
    {
        if (animCurve != null)
            transform.position = new Vector3(Time.time, animCurve.Evaluate(Time.time), 0);
    }
}