使用Unity3D生成网格并加贴图

        在使用Unity3D进行开发时，我们通常需要生成自己的网格来进行控制，比如进行图像变形等等。本文将介绍如何在Unity3D中生成一个网格。

        首先，需要在空间中生成顶点，然后在定义三角面片顶点序号。生成网格的代码如下：

using UnityEngine;
using System.Collections;
public class MeshGeneration : MonoBehaviour
{
Mesh mesh;
Vector3[] vertices;
Vector2[] uv;
int[] triangles;
Vector3[] normals;
void Start()
{
gameObject.AddComponent<MeshFilter>();
gameObject.AddComponent<MeshRenderer>();
Texture img = (Texture)Resources.Load("tu");
gameObject.GetComponent<Renderer>().material.mainTexture = img;
mesh = new Mesh();
int m = 5; //row  
int n = 10;  //col  
float width = 8;
float height = 6;
vertices = new Vector3[(m + 1) * (n + 1)];//the positions of vertices 
normals = new Vector3[(m + 1) * (n + 1)];
uv = new Vector2[(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);
normals[i] = new Vector3(0,0,-1);
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;
}
//三角形顶点顺序会影响显示方向
triangles[i * 3] = triIndex[0];
triangles[i * 3 + 1] = triIndex[2];
triangles[i * 3 + 2] = triIndex[1];
}
mesh.vertices = vertices;
mesh.uv = uv;
mesh.triangles = triangles;
mesh.normals = normals;
this.GetComponent<MeshFilter>().mesh = mesh;
}
}

        下图中的风景图片就是将贴图直接贴在网格上的结果。看上去效果和直接将贴图扔到一个plane上是一样的。但是我们可以控制网格顶点的数量，自由度大大增加。