在球面上“均匀”分布物体

在一个球体上均匀分布多个prefab。方法：
球面上坐标满足x^2+y2+z^2=R。以y轴向上为例
x = R * sin（alpha）cos（beta）；
y = R * cos（alpha）；
z = R * sin（alpha）sin（beta）；

在unity实现：

public class DistributeLight : MonoBehaviour
{

    // Use this for initialization
    public GameObject prefab;
    public int alphaStep = 12;
    public int betaStep = 4;

    public float R = 5.0f;

    float Deg2Rad (float angle)
    {
        float rad = angle * Mathf.PI * 2 / 360;
        return rad;
    }

    void CaculateSpherePosition ()
    {
        float alpha = 360.0f/alphaStep;
        float beta = 360.0f/betaStep;
        List<Vector3> posList = new List<Vector3> ();
        posList.Clear ();
        for (float i = 0.0f; i < 90.01f; i = i + alpha)
        {
            if (i == 0.0f)
            {
                Vector3 p = new Vector3 (0.0f, R, 0.0f);
                posList.Add (p);
                continue;
            }

            float R2 = R * Mathf.Sin (Deg2Rad (i));

            for (float j = 0.0f; j < 360.0f; j = j + beta)
            {
                Vector3 p = new Vector3 (R2 * Mathf.Cos (Deg2Rad (j)), R * Mathf.Cos (Deg2Rad (i)), R2 * Mathf.Sin (Deg2Rad (j)));
                posList.Add (p);
            }
            //step += 4;
        }
    
        int ii = 0;
        foreach (Vector3 pos in posList)
        {
            GameObject temp = Instantiate (prefab) as GameObject;
            temp.name = temp.name + ii;
            ii++;
            temp.transform.localPosition = pos;
            temp.transform.LookAt (new Vector3 (0, 0, 0));
            Debug.Log (pos);
        }
    }

    void Start ()
    {
        CaculateSpherePosition ();
    }
    
    // Update is called once per frame
    void Update ()
    {
        
    }

结果长这样：

image.png