unity中动态生成网格

以下是绘制正方形面片的一个例子，方便之后查阅：

效果如图所示：

红轴为x方向，蓝轴为z方向。

代码如下：

 using System.Collections;
 using System.Collections.Generic;
 using UnityEngine;
 public class SingleMesh:MonoBehaviour
 {
     public int size = ;//边长
     public int segment = ;//分段数
     public Material mat;//mesh材质
     private Vector3[] vertices;//顶点
     private Vector2[] uv;//纹理坐标
     private int[] triangles;//索引

     [ContextMenu("Create Mesh")]
     /// <summary>
     /// 创建mesh
     /// </summary>
     private void CreateMesh()
     {
         GameObject obj_cell = new GameObject();
         obj_cell.name = "cell";
         Mesh mesh = new Mesh();
         mesh.Clear();
         SetVertivesUV();//生成顶点和uv信息
         SetTriangles();//生成索引
         mesh.vertices = vertices;
         mesh.uv = uv;
         mesh.triangles = triangles;

         mesh.RecalculateNormals();//重置法线

         mesh.RecalculateBounds();   //重置范围
         obj_cell.AddComponent<MeshFilter>().mesh = mesh;
         obj_cell.AddComponent<MeshRenderer>();
         obj_cell.GetComponent<MeshRenderer>().material = mat;
     }

     /// <summary>
     /// 设置顶点信息
     /// </summary>
     private void SetVertivesUV()
     {
         vertices = new Vector3[(segment + ) * (segment + )];
         uv = new Vector2[vertices.Length];
         int num = ;
         float m = (float)size / (float)segment;
         for (int i = ; i < segment + ; i++)
             for (int j = ; j < segment + ; j++)
             {
                 vertices[num] = new Vector3(j * m,, i * m);
                 uv[num] = new Vector2((float)j / segment, (float)i / segment);
                 num++;
             }

     }
     /// <summary>
     /// 设置索引
     /// </summary>
     private void SetTriangles()
     {
         triangles = new int[segment * segment * ];
         int index = ;//用来给三角形索引计数
         for (int i = ; i < segment; i++)
             for (int j = ; j < segment; j++)
             {
                 int line = segment + ;
                 int self = j + (i * line);

                 triangles[index] = self;
                 triangles[index + ] = self + line + ;
                 triangles[index + ] = self + ;
                 triangles[index + ] = self;
                 triangles[index + ] = self + line;
                 triangles[index + ] = self + line + ;

                 index += ;
             }
     }
 }

其中triangles索引为链接各定点的顺序，一个小格的链接顺序如下：

准则：三角形有两面，正面可见，背面不可见。三角形的渲染顺序与三角形的正面法线呈左手螺旋定则。大部分按顺时针：012,213