public class AchimedeanSpiral : MonoBehaviour
{
    //极坐标方程为: r = a + bθ
    //平面笛卡尔坐标方程式为: x = (a + bθ)cos(θ), y = (a + bθ)sin(θ)
    //a: 当θ=0°时的极径(mm)
    //b: 阿基米德螺旋线系数(mm/°),表示每旋转1度时极径的增加/减小量
    //θ: 极角,单位为度,表示阿基米德螺旋线转过的总度数（弧度）
    //改变参数a将改变螺线形状,b控制螺线间距离,通常其为常量
 
    //公式参数
    [SerializeField] float parameA = 1;
    [SerializeField] float parameB = 1;
    [SerializeField] float parameAngle = 2 * Mathf.PI;
 
    //Z值变化
    [SerializeField] float spiralHeightAdded = 0.5f;
 
    //取点间隔角度（弧度）
    [SerializeField] float intervalAngle = 0.1f;
 
    //保存取样点
    List<Vector3> spiralPointList = new List<Vector3>();
 
    //绘制曲线
    [SerializeField] LineRenderer lineRenderer;
 
    void Update()
    {
        if (Input.GetMouseButtonDown(1))
            DrawSpiral();
    }
 
    void DrawSpiral()
    {
        spiralPointList.Clear();
 
        //隔固定角度取样
        float drawAngle = 0;
        while (drawAngle <= parameAngle)
        {
            spiralPointList.Add(GetPointByAngle(drawAngle));
            drawAngle += intervalAngle;
        }
 
        lineRenderer.positionCount = spiralPointList.Count;
        lineRenderer.SetPositions(spiralPointList.ToArray());
    }
 
    float tempX, tempY, tempZ;
    Vector3 GetPointByAngle(float angle)
    {
        //公式计算坐标
        tempX = (parameA + parameB * angle) * Mathf.Cos(angle);
        tempY = (parameA + parameB * angle) * Mathf.Sin(angle);
        //Z值增量
        tempZ = spiralHeightAdded * angle;
        return new Vector3(tempX, tempY, tempZ);
    }
 
}