使用Unity3D的网格功能生成自己的球体网格模型

        前面已经讲过怎样使用mesh生成一个自己的网格，那么本文将会讲述怎样将这个网格变换成自己想要的形状，比如一个球体。

我们需要知道一个从平面坐标到球体坐标的映射公式。假设平面坐标是（x，y），球体坐标是（x₀，y₀，z₀），则

      

        球体坐标（x₀，y₀，z₀）可以通过以下代码得到，（x，y） 对应vertices[i].x和vertices[i].y。

            v.x = r * Mathf.Cos(vertices[i].x / width * 2 * Mathf.PI) * Mathf.Cos(vertices[i].y / height * Mathf.PI - Mathf.PI / 2);
            v.y = r * Mathf.Sin(vertices[i].x / width * 2 * Mathf.PI) * Mathf.Cos(vertices[i].y / height * Mathf.PI - Mathf.PI / 2);
            v.z = r * Mathf.Sin(vertices[i].y / height * Mathf.PI - Mathf.PI / 2);

           完整代码在最后，将完整的脚本绑定到一个空物体上，把棋盘格图案chessboard.jpg放到AssetsResources下，还要在场景中生成一个sphere作为显示网格顶点的辅助物体。一切就绪后，运行效果如下：

using UnityEngine;
using System.Collections;

public class BallMesh : MonoBehaviour
{

    Mesh mesh;
    Vector3[] vertices;
    Vector2[] uv;
    int[] triangles;
    Vector3[] normals;
    public GameObject sphere;
    GameObject[] spheres;
    
    void Start()
    {
        gameObject.AddComponent<MeshFilter>();
        gameObject.AddComponent<MeshRenderer>();
        Texture img = (Texture)Resources.Load("tm");
        gameObject.GetComponent<Renderer>().material.mainTexture = img;
        mesh = new Mesh();
        int m = 25; //row  
        int n = 50;  //col  
        float width = 8;
        float height = 6;
        vertices = new Vector3[(m + 1) * (n + 1)];//the positions of vertices  
        spheres = new GameObject[(m + 1) * (n + 1)];
        uv = new Vector2[(m + 1) * (n + 1)];
        normals = new Vector3[(m + 1) * (n + 1)];
        triangles = new int[6 * m * n];
        for (int i = 0; i < vertices.Length; i++)
        {
            float x = i % (n + 1);
            float y = i / (n + 1);
            float x_pos = x / n * width;
            float y_pos = y / m * height;
            vertices[i] = new Vector3(x_pos, y_pos, 0);
            float u = x / n;
            float v = y / m;
            uv[i] = new Vector2(u, v);
        }
        for (int i = 0; i < 2 * m * n; i++)
        {
            int[] triIndex = new int[3];
            if (i % 2 == 0)
            {
                triIndex[0] = i / 2 + i / (2 * n);
                triIndex[1] = triIndex[0] + 1;
                triIndex[2] = triIndex[0] + (n + 1);
            }
            else
            {
                triIndex[0] = (i + 1) / 2 + i / (2 * n);
                triIndex[1] = triIndex[0] + (n + 1);
                triIndex[2] = triIndex[1] - 1;

            }
            triangles[i * 3] = triIndex[0];
            triangles[i * 3 + 1] = triIndex[1];
            triangles[i * 3 + 2] = triIndex[2];
        }
       
        int r = 10;
        for (int i = 0; i < vertices.Length; i++)
        {
            spheres[i] =  Instantiate( sphere,this.transform) as GameObject;
            Vector3 v ;
            v.x = r * Mathf.Cos(vertices[i].x / width * 2 * Mathf.PI) * Mathf.Cos(vertices[i].y / height * Mathf.PI - Mathf.PI / 2);
            v.y = r * Mathf.Sin(vertices[i].x / width * 2 * Mathf.PI) * Mathf.Cos(vertices[i].y / height * Mathf.PI - Mathf.PI / 2);
            v.z = r * Mathf.Sin(vertices[i].y / height * Mathf.PI - Mathf.PI / 2);
            //v = vertices[i];

            vertices[i] = v;
            spheres[i].transform.localPosition = v;

            normals[i] = new Vector3(0,1,0);
        }
        
        mesh.vertices = vertices;
        mesh.normals = normals;
        mesh.uv = uv;
        mesh.triangles = triangles;
        this.GetComponent<MeshFilter>().mesh = mesh;

    }

}