Version: 2020.2

# Vector3.Lerp

public static Vector3 Lerp (Vector3 a, Vector3 b, float t);

## 参数

 a 起始值，当 t = 0 时返回。 b 结束值，当 t = 1 时返回。 t 用于在 a 和 b 之间进行插值的值。

## 返回

Vector3 插值，等于 a + (b - a) * t。

## 描述

`t` = 0 时，Vector3.Lerp(a, b, t) 返回 /a/。
`t` = 1 时，Vector3.Lerp(a, b, t) 返回 /b/。
`t` = 0.5 时，Vector3.Lerp(a, b, t) 返回 `a``b` 中间的点。

```// A short example of Vector3.Lerp usage.
// Add it to an object in your scene, and at Play time it will draw in the Scene View a small yellow line between the scene origin, and a position interpolated between two other positions (one on the up axis, one on the forward axis).using UnityEngine;public class ExampleClass : MonoBehaviour
{
public int interpolationFramesCount = 45; // Number of frames to completely interpolate between the 2 positions
int elapsedFrames = 0;    void Update()
{
float interpolationRatio = (float)elapsedFrames / interpolationFramesCount;        Vector3 interpolatedPosition = Vector3.Lerp(Vector3.up, Vector3.forward, interpolationRatio);        elapsedFrames = (elapsedFrames + 1) % (interpolationFramesCount + 1);  // reset elapsedFrames to zero after it reached (interpolationFramesCount + 1)        Debug.DrawLine(Vector3.zero, Vector3.up, Color.green);
Debug.DrawLine(Vector3.zero, Vector3.forward, Color.blue);
Debug.DrawLine(Vector3.zero, interpolatedPosition, Color.yellow);
}
}
```
```// A longer example of Vector3.Lerp usage.
// Drop this script under an object in your scene, and specify 2 other objects in the "startMarker"/"endMarker" variables in the script inspector window.
// At play time, the script will move the object along a path between the position of those two markers.using UnityEngine;
using System.Collections;public class ExampleClass : MonoBehaviour
{
// Transforms to act as start and end markers for the journey.
public Transform startMarker;
public Transform endMarker;    // Movement speed in units per second.
public float speed = 1.0F;    // Time when the movement started.
private float startTime;    // Total distance between the markers.
private float journeyLength;    void Start()
{
// Keep a note of the time the movement started.
startTime = Time.time;        // Calculate the journey length.
journeyLength = Vector3.Distance(startMarker.position, endMarker.position);
}    // Move to the target end position.
void Update()
{
// Distance moved equals elapsed time times speed..
float distCovered = (Time.time - startTime) * speed;        // Fraction of journey completed equals current distance divided by total distance.
float fractionOfJourney = distCovered / journeyLength;        // Set our position as a fraction of the distance between the markers.
transform.position = Vector3.Lerp(startMarker.position, endMarker.position, fractionOfJourney);
}
}
```