Vector3.MoveTowards

参数

返回

Vector3 新位置。

描述

计算 current 指定的点与 target 指定的点之间的位置，移动距离不超过 maxDistanceDelta 指定的距离。

使用 MoveTowards 成员将 current 位置处的对象移向 target 位置。通过使用此函数计算的位置来更新每个帧的对象位置，您可以平滑地将其移向目标。使用 maxDistanceDelta 参数来控制移动的速度。如果 current 位置相比 maxDistanceDelta 更靠近 maxDistanceDelta，则返回值等于 maxDistanceDelta；新位置不会过冲 maxDistanceDelta。要确保对象速度与帧率无关，请将 maxDistanceDelta 值乘以 Time.deltaTime（或者 FixedUpdate 循环中的 Time.fixedDeltaTime）。

请注意，如果将 maxDistanceDelta 设置为负值，则该函数将返回与 target 相反方向的位置。

using UnityEngine;
using System.Collections;

// Vector3.MoveTowards example.

// A cube can be moved around the world. It is kept inside a 1 unit by 1 unit
// xz space. A small, long cylinder is created and positioned away from the center of
// the 1x1 unit. The cylinder is moved between two locations. Each time the cylinder is
// positioned the cube moves towards it. When the cube reaches the cylinder the cylinder
// is re-positioned to the other location. The cube then changes direction and moves
// towards the cylinder again.
//
// A floor object is created for you.
//
// To view this example, create a new 3d Project and create a Cube placed at
// the origin. Create Example.cs and change the script code to that shown below.
// Save the script and add to the Cube.
//
// Now run the example.

public class Example : MonoBehaviour
{
    // Adjust the speed for the application.
    public float speed = 1.0f;

    // The target (cylinder) position.
    private Transform target;

    void Awake()
    {
        // Position the cube at the origin.
        transform.position = new Vector3(0.0f, 0.0f, 0.0f);

        // Create and position the cylinder. Reduce the size.
        GameObject cylinder = GameObject.CreatePrimitive(PrimitiveType.Cylinder);
        Camera.main.transform.position = new Vector3(0.85f, 1.0f, -3.0f);

        // Grab cylinder values and place on the target.
        target = cylinder.transform;
        target.transform.localScale = new Vector3(0.15f, 1.0f, 0.15f);
        target.transform.position = new Vector3(0.8f, 0.0f, 0.8f);

        // Position the camera.
        Camera.main.transform.position = new Vector3(0.85f, 1.0f, -3.0f);
        Camera.main.transform.localEulerAngles = new Vector3(15.0f, -20.0f, -0.5f);

        // Create and position the floor.
        GameObject floor = GameObject.CreatePrimitive(PrimitiveType.Plane);
        floor.transform.position = new Vector3(0.0f, -1.0f, 0.0f);
    }

    void Update()
    {
        // Move our position a step closer to the target.
        float step =  speed * Time.deltaTime; // calculate distance to move
        transform.position = Vector3.MoveTowards(transform.position, target.position, step);

        // Check if the position of the cube and sphere are approximately equal.
        if (Vector3.Distance(transform.position, target.position) < 0.001f)
        {
            // Swap the position of the cylinder.
            target.position *= -1.0f;
        }
    }
}