Unity相机局部旋转异常求助：单轴丢失局部朝向

问题根源 #

• 旋转轴错误使用了Player对象的世界空间轴向（transform.up/transform.right/transform.forward），而非相机当前的局部空间轴向，导致旋转偏离局部坐标系统。
• 从Quaternion.identity重新构建旋转的方式，相当于每次丢弃相机当前的旋转状态，从初始值叠加，无法保持局部朝向的连续性。

修正后的代码 #

public class Player : MonoBehaviour
{
    [Header("Camera")]
    [SerializeField] private Camera _camera;
    [SerializeField] private Vector2 _xMinMaxRotation = new Vector2(-90, 90);
    [SerializeField] private Vector2 _yMinMaxRotation = new Vector2(-90, 90);
    [SerializeField] private Vector2 _zMinMaxRotation = new Vector2(-25, 25);
    [SerializeField] private float _mouseXSensistivity = 1f;
    [SerializeField] private float _mouseYSensistivity = 1f;
    [SerializeField] private float _mouseZSensistivity = 1f;
    [SerializeField] private float _xStartRotation = 0f;
    [SerializeField] private float _yStartRotation = 0f;
    [SerializeField] private float _zStartRotation = 0f;

    private float _currentXRot;
    private float _currentYRot;
    private float _currentZRot;

    void Start()
    {
        Cursor.lockState = CursorLockMode.Locked;
        _currentXRot = _xStartRotation;
        _currentYRot = _yStartRotation;
        _currentZRot = _zStartRotation;
        UpdateCameraRotation();
    }

    void Update()
    {
        var mouseDelta = new Vector2(Input.GetAxis("Mouse X"), Input.GetAxis("Mouse Y"));
        UpdateCameraRotationInput(mouseDelta);
    }

    private void UpdateCameraRotationInput(Vector2 mouseDelta)
    {
        _currentXRot += mouseDelta.x * _mouseXSensistivity * Time.deltaTime * 100f;
        _currentYRot -= mouseDelta.y * _mouseYSensistivity * Time.deltaTime * 100f;

        if (Input.GetKey(KeyCode.Q))
        {
            _currentZRot += _mouseZSensistivity * Time.deltaTime * 50f;
        }
        else if (Input.GetKey(KeyCode.E))
        {
            _currentZRot -= _mouseZSensistivity * Time.deltaTime * 50f;
        }
        else
        {
            _currentZRot = Mathf.MoveTowards(_currentZRot, 0f, 2f * _mouseZSensistivity * Time.deltaTime * 50f);
        }

        _currentXRot = Mathf.Clamp(_currentXRot, _xMinMaxRotation.x, _xMinMaxRotation.y);
        _currentYRot = Mathf.Clamp(_currentYRot, _yMinMaxRotation.x, _yMinMaxRotation.y);
        _currentZRot = Mathf.Clamp(_currentZRot, _zMinMaxRotation.x, _zMinMaxRotation.y);

        UpdateCameraRotation();
    }

    private void UpdateCameraRotation()
    {
        // 直接设置相机局部欧拉角，Unity自动转换为局部空间四元数，避免万向锁
        Quaternion rotation = Quaternion.Euler(_currentYRot, _currentXRot, _currentZRot);
        _camera.transform.localRotation = rotation;
    }
}

关键修正点 #

1. 局部空间旋转：通过Quaternion.Euler设置相机的localRotation，确保旋转基于相机自身的局部坐标系统，而非Player的世界坐标。
2. 简化Z轴逻辑：用Mathf.MoveTowards替代冗余的条件判断，实现更平滑的自动回正效果。
3. 状态连续更新：基于当前累积的旋转值更新相机状态，保持局部朝向的连续性，而非每次从初始状态重建旋转。

可选：纯四元数增量旋转（更严谨的局部旋转） #

如果希望完全通过四元数增量更新（避免欧拉角的潜在问题），可以替换UpdateCameraRotation方法：

private void UpdateCameraRotation()
{
    Quaternion currentRot = _camera.transform.localRotation;

    // 计算各轴的增量旋转（基于局部空间轴）
    Quaternion xDeltaRot = Quaternion.AngleAxis(_currentXRot - currentRot.eulerAngles.y, Vector3.up);
    Quaternion yDeltaRot = Quaternion.AngleAxis(_currentYRot - currentRot.eulerAngles.x, Vector3.right);
    Quaternion zDeltaRot = Quaternion.AngleAxis(_currentZRot - currentRot.eulerAngles.z, Vector3.forward);

    // 四元数右乘：新旋转应用在当前旋转的局部空间
    _camera.transform.localRotation = yDeltaRot * xDeltaRot * zDeltaRot * currentRot;
}

内容的提问来源于stack exchange，提问作者Vincent Mazzarella