Unity | 物体上下浮动效果

原文：Making Objects Float Up & Down in Unity

// Floater v0.0.2
// by Donovan Keith
//
// [MIT License](https://opensource.org/licenses/MIT)
 
using UnityEngine;
using System.Collections;
 
// Makes objects float up & down while gently spinning.
public class Floater : MonoBehaviour {
    // User Inputs
    public float degreesPerSecond = 15.0f;
    public float amplitude = 0.5f;
    public float frequency = 1f;
 
    // Position Storage Variables
    Vector3 posOffset = new Vector3 ();
    Vector3 tempPos = new Vector3 ();
 
    // Use this for initialization
    void Start () {
        // Store the starting position & rotation of the object
        posOffset = transform.position;
    }
     
    // Update is called once per frame
    void Update () {
        // Spin object around Y-Axis
        transform.Rotate(new Vector3(0f, Time.deltaTime * degreesPerSecond, 0f), Space.World);
 
        // Float up/down with a Sin()
        tempPos = posOffset;
        tempPos.y += Mathf.Sin (Time.fixedTime * Mathf.PI * frequency) * amplitude;
 
        transform.position = tempPos;
    }
}

思路

记录物体原本的位置，在此基础上使用Mathf.Sin()函数，让物体上下浮动（类似为横波的简谐运动）

1 浮动

posOffset 为物体的初始位置，先记录下来
修改其y即数值方向的坐标：tempPos.y += Mathf.Sin(...)

(Time.fixedTime * Mathf.PI * frequency) 和 amplitude
相当于频率（快慢）和幅度（强度）

2 旋转

transform.Rotate(new Vector3(0f, Time.deltaTime * degreesPerSecond, 0f), Space.World);

绕何轴旋转，将何轴以外置为0

效果