Unity相机旋转优化：实现达最大转速后平滑换向并减速至停止

问题描述 #

现有BallManager脚本中，相机达到maxRotationSpeed后，当前逻辑会导致转速减速到0后变为负值，进而反向旋转且转速不断递增，不符合达到最大转速后平滑切换旋转方向并缓慢减速至0的需求。

修复后的完整代码 #

using System.Collections;
using TMPro;
using UnityEngine;

public class BallManager : MonoBehaviour
{
    public GameObject ballPrefab;
    public int numberOfBalls = 10;
    public float fallSpeed = 5;
    public float spawningSpeed = 1;
    public float ballSize = 1f;
    public bool randomSize = false;
    public TextMeshProUGUI ballCountText; // Reference to the TextMeshPro Text
    public float maxRotationSpeed = 180.0f;
    public float rotationSpeed = 10.0f; // Initial rotation speed (when it starts)
    public float timeToReachMaxSpeed = 30.0f; // Time in seconds to reach maximum rotation speed
    public float timeToDecelerate = 10.0f; // 控制从最大转速减速到0的时长
    public float currentRotationSpeed; // Variable to display the current rotation speed in the inspector

    private int ballCount; // Counter for the number of balls
    private Transform cameraTransform;
    private int rotationDirection = 1; // 1为正方向旋转，-1为反方向旋转

    private void Start()
    {
        cameraTransform = Camera.main.transform;
        currentRotationSpeed = rotationSpeed; // Initialize currentRotationSpeed
        StartCoroutine(SpawnBalls());
        StartCoroutine(StartCameraRotation());
    }

    private IEnumerator SpawnBalls()
    {
        for (int i = 0; i < numberOfBalls; i++)
        {
            GameObject ball = Instantiate(ballPrefab, transform.position, Quaternion.identity);

            if (randomSize)
            {
                float randomScale = Random.Range(0.5f, 2.0f); // Random size between 0.5 and 2
                ball.transform.localScale = new Vector3(randomScale, randomScale, randomScale);
            }
            else
            {
                ball.transform.localScale = new Vector3(ballSize, ballSize, ballSize);
            }

            Rigidbody rb = ball.GetComponent<Rigidbody>();
            rb.velocity = Vector3.down * fallSpeed;

            // Randomize bouncing direction
            Vector3 randomDirection = new Vector3(Random.Range(-1f, 1f), 0, Random.Range(-1f, 1f)).normalized;
            rb.AddForce(randomDirection * 5f, ForceMode.Impulse);

            // Increase the ball count and update the TextMeshPro Text
            ballCount++;
            ballCountText.text = "Balls: " + ballCount;

            yield return new WaitForSeconds(spawningSpeed); // Time delay between spawning balls
        }
    }

    private IEnumerator StartCameraRotation()
    {
        float timer = 0.0f;

        // 阶段1：从初始转速平滑加速到最大转速
        while (timer < timeToReachMaxSpeed)
        {
            timer += Time.deltaTime;
            currentRotationSpeed = Mathf.Lerp(rotationSpeed, maxRotationSpeed, timer / timeToReachMaxSpeed);

            cameraTransform.RotateAround(transform.position, Vector3.up, currentRotationSpeed * rotationDirection * Time.deltaTime);

            yield return null;
        }

        // 阶段2：切换旋转方向并平滑减速至0
        timer = 0.0f;
        rotationDirection *= -1; // 立即切换旋转方向
        while (timer < timeToDecelerate)
        {
            timer += Time.deltaTime;
            // 从最大转速线性插值到0，保证减速平滑
            currentRotationSpeed = Mathf.Lerp(maxRotationSpeed, 0, timer / timeToDecelerate);

            cameraTransform.RotateAround(transform.position, Vector3.up, currentRotationSpeed * rotationDirection * Time.deltaTime);

            yield return null;
        }

        // 减速完成后固定转速为0
        currentRotationSpeed = 0;
    }
}

关键修改说明 #

• 新增timeToDecelerate变量：可视化控制减速时长，方便调整平滑度。
• 用rotationDirection替代原changeDir：用整数1/-1直接控制旋转方向，逻辑更直观，避免状态判断混乱。
• 拆分旋转流程为两个明确阶段：
  1. 加速阶段：保持原逻辑从初始转速平滑提升到最大值。
  2. 切换减速阶段：先反转方向，再通过Mathf.Lerp将转速从最大值线性降到0，彻底解决负转速递增的问题。
• 移除无限循环：减速完成后直接停止旋转，完全匹配需求中"减速至0"的目标（若需要循环切换方向，可在减速完成后重新调用加速/减速逻辑）。

内容的提问来源于stack exchange，提问作者Daniel Lip