외부 패키지 없이 구현하는 감쇠 진폭 2D/3D 카메라 셰이크(Camera Shake)

using UnityEngine;

public class CameraShake : MonoBehaviour
{
    public static CameraShake Instance { get; private set; }

    [SerializeField] private float frequency = 25f;
    [SerializeField] private float maxAngle = 5f;
    [SerializeField] private float maxOffset = 0.5f;
    [SerializeField] private float decaySpeed = 1.5f;

    private float _trauma = 0f;
    private Vector3 _originalPos;
    private float _timeCounter;

    private void Awake()
    {
        Instance = this;
        _originalPos = transform.localPosition;
    }

    public void Shake(float amount)
    {
        _trauma = Mathf.Clamp01(_trauma + amount);
    }

    private void LateUpdate()
    {
        if (_trauma > 0f)
        {
            _timeCounter += Time.deltaTime * frequency;
            float shakeStrength = _trauma * _trauma; // 비선형 반응 (자연스러운 체감)

            float offsetX = (Mathf.PerlinNoise(_timeCounter, 0f) * 2f - 1f) * maxOffset * shakeStrength;
            float offsetY = (Mathf.PerlinNoise(0f, _timeCounter) * 2f - 1f) * maxOffset * shakeStrength;
            float rotZ = (Mathf.PerlinNoise(_timeCounter, _timeCounter) * 2f - 1f) * maxAngle * shakeStrength;

            transform.localPosition = _originalPos + new Vector3(offsetX, offsetY, 0f);
            transform.localRotation = Quaternion.Euler(0f, 0f, rotZ);

            _trauma = Mathf.MoveTowards(_trauma, 0f, Time.deltaTime * decaySpeed);
        }
        else
        {
            transform.localPosition = _originalPos;
            transform.localRotation = Quaternion.identity;
        }
    }
}