【Unity3D】实现太阳系

    实践要求：写一个程序，实现一个完整的太阳系，其他星球围绕太阳的转速必须不一样，并且不再一个法平面内。

    法平面是指过空间曲线的切点，且与切线垂直的平面。要求不在一个法平面内，则在保证所有行星以及太阳在一条轴上时，另外两条轴的比例不相同即可。公转速度在RotateAround参数里面设置。如：

    这个程序在课堂程序的基础上完成，使用了预制、动态生成对象，在位置上使用Vector3定好行星初始位置，使用RotateAround设置行星公转，使用Rotate设置行星自转。参数大部分参照了太阳系的参数，如行星大小，公转速度等按比例模拟。

显示效果：

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制作概述：

1.制作太阳系预制

根据太阳系各行星的大小设置Transform中的Scale

想要给白色的球贴上图的，可以去网上找到太阳系贴图，直接百度搜索就好。

然后导入图片资源，再将对应的图片拖到对应的行星即可。

最后将Sun整个拖入Assets/Resources/Perfabs（这一步是为了后续改进，直接放在Hierarchy里面后面再挂载cs文件就可以直接运行）

到这预制就做好啦~

2.开始编写代码~

使用了课程中的MVC架构

新建一个RoundSun.cs

cs文件：

2.1声明对象

    public Transform Sun;
    public Transform Mercury;
    public Transform Venus;
    public Transform Earth;
        public Transform Moon;
    public Transform Mars;
    public Transform Jupiter;
    public Transform Saturn;
    public Transform Uranus;
    public Transform Neptune;
    public Transform Pluto;

2.2初始行星位置

void Start () {
        Sun.position = Vector3.zero;
        Mercury.position = new Vector3 (4, 0, 0);
        Venus.position = new Vector3 (6, 0, 0);
        Earth.position = new Vector3 (8, 0, 0);
            Moon.position = new Vector3 (10, 0, 0);
        Mars.position = new Vector3 (12, 0, 0);
        Jupiter.position = new Vector3 (16, 0, 0);
        Saturn.position = new Vector3 (20, 0, 0);
        Uranus.position = new Vector3 (24, 0, 0);
        Neptune.position = new Vector3 (28, 0, 0);
        Pluto.position = new Vector3 (32, 0, 0);
    }

2.3设置行星公转和自转

手动设置的参数，与真实太阳系有偏差

void Update () {
        Vector3 a1 = new Vector3 (0, 9, 2);
        Vector3 a2 = new Vector3 (0, 257, 135);
        Vector3 a3 = new Vector3 (0, 45, 339);
        Vector3 a4 = new Vector3 (0, 4, 9);
        Vector3 a5 = new Vector3 (0, 8, 19);
        Vector3 a6 = new Vector3 (0, 11, 9);
        Vector3 a7 = new Vector3 (0, 6, 137);
        Vector3 a8 = new Vector3 (0, 3, 13);
        Vector3 a9 = new Vector3 (0, 13, 122);
        
        Mercury.RotateAround (Sun.position, a1, 20*Time.deltaTime);
        Mercury.Rotate (Vector3.up*50*Time.deltaTime);

        Venus.RotateAround (Sun.position, a2, 10*Time.deltaTime);
        Venus.Rotate (Vector3.up*30*Time.deltaTime);

        Earth.RotateAround (Sun.position, a3, 10*Time.deltaTime);
        Earth.Rotate (Vector3.up*30*Time.deltaTime);
        Moon.transform.RotateAround (Earth.position, Vector3.up, 359 * Time.deltaTime);

        Mars.RotateAround (Sun.position, a4, 8*Time.deltaTime);
        Mars.Rotate (Vector3.up*30*Time.deltaTime);

        Jupiter.RotateAround (Sun.position, a5, 7*Time.deltaTime);
        Jupiter.Rotate (Vector3.up*30*Time.deltaTime);

        Saturn.RotateAround (Sun.position, a6, 6*Time.deltaTime);
        Saturn.Rotate (Vector3.up*30*Time.deltaTime);

        Uranus.RotateAround (Sun.position, a7, 5*Time.deltaTime);
        Uranus.Rotate (Vector3.up*30*Time.deltaTime);

        Neptune.RotateAround (Sun.position, a8, 4*Time.deltaTime);
        Neptune.Rotate (Vector3.up*30*Time.deltaTime);

        Pluto.RotateAround (Sun.position, a9, 3*Time.deltaTime);
        Pluto.Rotate (Vector3.up*30*Time.deltaTime);
    }

这时候直接将cs挂载到Sun里，到这里已经可以运行实现啦。

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接下来实现预制，动态生成对象吧。直接放代码。

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

public class FirstController : MonoBehaviour, ISceneController {
    void Awake() {
        Debug.Log ("load sunt...
");
        SSDirector director = SSDirector.getInstance ();
        director.setFPS (60);
        director.currentSceneController = this;
        director.currentSceneController.LoadResources ();
    }

    public void LoadResources() {
        GameObject sunset = Instantiate<GameObject> (
                                Resources.Load <GameObject> ("Perfabs/Sun"),
                                Vector3.zero, Quaternion.identity);
        sunset.name = "sunset";
        Debug.Log ("load sunset...
");
    }
    public void Pause(){
    }
    public void Resume(){
    }
    // Use this for initialization
    void Start () {
        
    }
    
    // Update is called once per frame
    void Update () {
        
    }
}

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

    public interface ISceneController {
        void LoadResources();
        void Pause();
        void Resume();
    }

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

public class SSDirector : System.Object {
    private static SSDirector _instance;

    public ISceneController currentSceneController { get; set; }
    public bool running{ get; set; }

    public static SSDirector getInstance() {
        if (_instance == null) {
            _instance = new SSDirector ();
        }
        return _instance;
    }

    public int getFPS() {
        return Application.targetFrameRate;
    }

    public void setFPS(int fps) {
        Application.targetFrameRate = fps;
    }
}

在确保

在这个文件目录下

将FirstController挂载到主摄像机或者空对象即可运行

 大致架构：