Unity Flat Shading实现低多边形(low-poly)效果

原理：修改Mesh顶点及三角索引

获取模型的mesh网格，非蒙皮模型通过获取MeshFilter组件得到Mesh，带有蒙皮的模型通过Skinned Mesh Renderer组件获取Mesh。

MeshFilter meshFilter = GetComponent<MeshFilter>();
Mesh mesh = meshFilter.mesh;

修改模型mesh顶点以及三角索引：

Vector3[] oldVerts = mesh.vertices;//保存当前Mesh顶点
int[] triangles = mesh.triangles;//三角索引数组

Vector3[] verts = new Vector3[triangles.Length];//用于保存新的顶点信息

for (int i = 0; i < triangles.Length; i++)
{
verts[i] = oldVerts[triangles[i]];
triangles[i] = i;
}

mesh.vertices = verts;//更新Mesh顶点
mesh.triangles = triangles;//更新索引
mesh.RecalculateBounds();//重新计算边界
mesh.RecalculateNormals();//重新计算法线

将脚本赋予模型，运行即可得到low poly效果。为了避免每次执行进行顶点的计算以及修改，可以加上下面代码将修改后的Mesh保存成文件：

string fileName = "Assets/FileName.asset";//要保存成的文件路径及文件名 文件格式为.asset
AssetDatabase.CreateAsset(meshFilter.sharedMesh, fileName);//创建文件
AssetDatabase.SaveAssets();//保存数据

运行程序后会在Assets下生成Mesh文件，将此文件拖到该模型Mesh Filter组件下的Mesh，此时生成low poly的脚本组件已经无用了，记得移除



完整代码：

using UnityEngine;
using System.Collections;
using UnityEditor;
public class FlatShading : MonoBehaviour
{

private Mesh mesh;
void Start()
{
var meshFilter = GetComponent<MeshFilter>();
mesh = meshFilter.mesh;
Vector3[] oldVerts = mesh.vertices;
int[] triangles = mesh.triangles;

Vector3[] verts = new Vector3[triangles.Length];

for (int i = 0; i < triangles.Length; i++)
{
verts[i] = oldVerts[triangles[i]];
triangles[i] = i;
}

mesh.vertices = verts;
mesh.triangles = triangles;
mesh.RecalculateBounds();
mesh.RecalculateNormals();

//save file
string fileName = "Assets/" + System.DateTime.Now.Year.ToString()+ System.DateTime.Now.Month.ToString()+ System.DateTime.Now.Day.ToString()+ System.DateTime.Now.Hour.ToString()+ System.DateTime.Now.Minute.ToString()+ System.DateTime.Now.Second.ToString() + ".asset";
AssetDatabase.CreateAsset(meshFilter.sharedMesh, fileName);
AssetDatabase.SaveAssets();
}
}