XiJianYCYL/Assets/3D/Scripts/LocalRotator.cs

using System.Collections;
using System.Collections.Generic;
using UnityEngine;

public class LocalRotator : MonoBehaviour
{
    public float MaxAngle = 15;
    public AnimationCurve Curve;
    public float LoopLength;
    public float Offset;
    public Vector3 Axis = Vector3.up;

    Quaternion startRotation;
    float elapsedTime;

    private void Start()
    {
        startRotation = transform.localRotation;
        elapsedTime = Offset;
    }

    private void OnEnable()
    {
        elapsedTime = Offset;
    }

    private void Update()
    {
        if(float.IsNaN(elapsedTime))
        {
            elapsedTime = 0;
        }

        elapsedTime += Time.deltaTime;

        elapsedTime = Mathf.Repeat(elapsedTime, LoopLength);

        float fraction = elapsedTime / LoopLength;
        float value = Curve.Evaluate(fraction);

        transform.localRotation = Quaternion.AngleAxis(value * MaxAngle, Axis) * startRotation;
    }
}