ローレンツ方程式の挙動をUnityで再現するためのScript

ButterflyEffect.cs

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

public class ButterflyEffect : MonoBehaviour
{
    [SerializeField] Transform ball; //このオブジェクトにTrail Rendererをつけると可愛い
    [SerializeField] float scale = 0.002f; //scale=1だと大きすぎてARグラスで観測しにくい
    LorenzModel model;
    Vector3 initBallPosition;
    // Start is called before the first frame update
    void Start()
    {
        model = new LorenzModel(Time.fixedDeltaTime);
        initBallPosition = ball.transform.position;
    }
    void FixedUpdate() {
        UpdatePosition();
    }

    void UpdatePosition() {
        model.UpdatePosition() ;
        ball.transform.position = initBallPosition + model.GetPosition()*scale;
    }
}

public class LorenzModel {
    Vector3 position;
    Vector3 velocity;
    float deltaTime; //微小時間 = Time.fixedDeltaTime

    public LorenzModel(float deltaTime) {
        this.deltaTime = deltaTime;
        this.position = new Vector3(0,0.001f,0); //初期位置が原点だと動かないので適当にずらす。
    }
    
    //p,r,b:有名な初期値設定を採用
    float p = 10f; 
    float r = 28f;
    float b = 8f/3f;
    
    public void UpdatePosition() {
        velocity = new Vector3(-p*position.x+p*position.y,-position.x*position.z+r*position.x-position.y,position.x*position.y-b*position.z);
        position = position + velocity * deltaTime;
    }
    public Vector3 GetPosition() {
        return this.position;
    }
}