使用二十面体画球体

当做一个地球的时候，可以使用六面体，八面体和20面体来画一个球体，，下面是20面体画球体的代码

 public GameObject GetSphere(int subdivision = 5, float radius = 1.0f)
    {
        GameObject go = new GameObject ("Pentagon");
        MeshFilter filter = go.AddComponent<MeshFilter> ();
        
        Mesh mesh = new Mesh();
        filter.mesh = mesh;
        List<Vector3> vertices = new List<Vector3>()
        {
            new Vector3(0.000000f, -1.000000f, 0.000000f),
            new Vector3(0.723600f, -0.447215f, 0.525720f),
            new Vector3(-0.276385f, -0.447215f, 0.850640f),
            new Vector3(-0.894425f, -0.447215f, 0.000000f),
            new Vector3(-0.276385f, -0.447215f, -0.850640f),
            new Vector3(0.723600f, -0.447215f, -0.525720f),
            new Vector3(0.276385f, 0.447215f, 0.850640f),
            new Vector3(-0.723600f, 0.447215f, 0.525720f),
            new Vector3(-0.723600f, 0.447215f, -0.525720f),
            new Vector3(0.276385f, 0.447215f, -0.850640f),
            new Vector3(0.894425f, 0.447215f, 0.000000f),
            new Vector3(0.000000f, 1.000000f, 0.000000f),
        };
        int[] triangles =
        {
            0, 1, 2,
            1, 0, 5,
            0, 2, 3,
            0, 3, 4,
            0, 4, 5,
            1, 5, 10,
            2, 1, 6,
            3, 2, 7,
            4, 3, 8,
            5, 4, 9,
            1, 10, 6,
            2, 6, 7,
            3, 7, 8,
            4, 8, 9,
            5, 9, 10,
            6, 10, 11,
            7, 6, 11,
            8, 7, 11,
            9, 8, 11,
            10, 9, 11
        };

        for (int s = 0; s < subdivision; s++)
        {
            
            //这将存储连接中已经存在的所有顶点，因此不存在重复/重叠的顶点
            List<VertOnEdge> connected = new List<VertOnEdge>();

            //细分后的面数
            int[] newTriangles = new int[triangles.Length * 4];
            //遍历三角形面数
            for (int i = 0; i < triangles.Length / 3; i++)
            {
                //获取一个面的三个顶点
                int A = triangles[i * 3];
                int B = triangles[i * 3 + 1];
                int C = triangles[i * 3 + 2];

                int ab = -1;
                int bc = -1;
                int ca = -1;
                List<int> connectionToBeRemoved = new List<int>(); //需要删除的连接

                for (int j = 0; j < connected.Count; j++)
                {
                    VertOnEdge voe = connected[j];
                    if (voe.A == A)
                    {
                        if (voe.B == B)
                        {
                            ab = voe.vertIndex;
                            connectionToBeRemoved.Add(j);
                        }
                        else if (voe.B == C)
                        {
                            ca = voe.vertIndex;
                            connectionToBeRemoved.Add(j);
                        }
                    }
                    else if (voe.A == B)
                    {
                        //check if there is a connection between B and A or C
                        if (voe.B == A)
                        {
                            ab = voe.vertIndex;
                            connectionToBeRemoved.Add(j);
                        }
                        else if (voe.B == C)
                        {
                            bc = voe.vertIndex;
                            connectionToBeRemoved.Add(j);
                        }
                    }
                    else if (voe.A == C)
                    {
                        //check if there is a connection between C and A or B
                        if (voe.B == A)
                        {
                            ca = voe.vertIndex;
                            connectionToBeRemoved.Add(j);
                        }
                        else if (voe.B == B)
                        {
                            bc = voe.vertIndex;
                            connectionToBeRemoved.Add(j);
                        }
                    }
                }

                connectionToBeRemoved.Sort();
                connectionToBeRemoved.Reverse();
               
                for (int k = 0; k < connectionToBeRemoved.Count; k++)
                {
                    connected.RemoveAt(connectionToBeRemoved[k]);
                }
            

            //create new vertices and connections that don't exist
                if (ab == -1)
                {
                    vertices.Add((vertices[A] + vertices[B]) / 2);
                    ab = vertices.Count - 1;
                    connected.Add(new VertOnEdge(ab, A, B));
                }

                if (bc == -1)
                {
                    vertices.Add((vertices[B] + vertices[C]) / 2);
                    bc = vertices.Count - 1;
                    connected.Add(new VertOnEdge(bc, B, C));
                }

                if (ca == -1)
                {
                    vertices.Add((vertices[C] + vertices[A]) / 2);
                    ca = vertices.Count - 1;
                    connected.Add(new VertOnEdge(ca, C, A));
                }
                //4个三角形 12个顶点
                int triangleStartingIndex = i * 12;
                //在写入三角形的时候注意要顺时针写（opengl标准），逆时针写的时候面是反的
                newTriangles[triangleStartingIndex] = A;
                newTriangles[triangleStartingIndex + 1] = ab;
                newTriangles[triangleStartingIndex + 2] = ca;

                newTriangles[triangleStartingIndex + 3] = ab;
                newTriangles[triangleStartingIndex + 4] = B;
                newTriangles[triangleStartingIndex + 5] = bc;

                newTriangles[triangleStartingIndex + 6] = bc;
                newTriangles[triangleStartingIndex + 7] = C;
                newTriangles[triangleStartingIndex + 8] = ca;

                newTriangles[triangleStartingIndex + 9] = ab;
                newTriangles[triangleStartingIndex + 10] = bc;
                newTriangles[triangleStartingIndex + 11] = ca;
            }
            for (int i = 0; i < vertices.Count; i++)
            {
                vertices[i] = vertices[i].normalized;
            }
            triangles = null;
            triangles = newTriangles;
        }

        mesh.vertices = vertices.ToArray();
        mesh.triangles = triangles;
        mesh.RecalculateNormals();
        Material material = new Material (Shader.Find ("Diffuse"));
        material.SetColor ("_Color", Color.yellow);
 
        MeshRenderer renderer = go.AddComponent<MeshRenderer> ();
        renderer.sharedMaterial = material;

        return go;



    }