functionCombineMeshes(combine: CombineInstance[],mergeSubMeshes: bool = true,useMatrices: bool = true) : void

結合網格有利於效能最優化。如果mergeSubMeshes為true，所有的網格會被結合成一個單個子網格。否則每一個網格都將變成單個不同的子網格。如果所有的網格共享同一種材質，設定它為真。如果useMatrices為false，在CombineInstance結構中的變換矩陣將被忽略。

用這函式我們可以把引用相同材質球的網格進行合併達到減少Draw Call，優化效能的效果。

我的基本思路是：將所有的材質球用字典存（相同的只存一個）,將引用相同材質球的網格存一個連結串列中用材質球的名稱作為Key值;

然後遍歷字典用Mesh的成員方法CombineMeshes()合併相同;

OK，上程式碼

using UnityEngine;
using System.Collections;
using System.Collections.Generic;
 
public class ComebinMesheDemo : MonoBehaviour {
 
// Use this for initialization
void Start () {
//獲取所有網格過濾器;
MeshFilter[] meshFilters = gameObject.GetComponentsInChildren<MeshFilter>();
//存放不同的材質球，相同的就存一個;
Dictionary<string, Material> materials = new Dictionary<string, Material>();
 
//存放要合併的網格物件;
Dictionary<string, List<CombineInstance>> combines = new Dictionary<string, List<CombineInstance>>();
for (int i = 0; i < meshFilters.Length; i++)
{
//構造一個網格合併結構體;
CombineInstance combine = new CombineInstance();
 
//給結構體的mesh賦值;
combine.mesh = meshFilters[i].mesh;
combine.transform = meshFilters[i].transform.localToWorldMatrix;
 
MeshRenderer renderer = meshFilters[i].GetComponent<MeshRenderer>();
Material mat = renderer.sharedMaterial;
 
if (!materials.ContainsKey(mat.name))
{
materials.Add(mat.name, mat);
}
if (combines.ContainsKey(mat.name))
{
combines[mat.name].Add(combine);
}
else
{
List<CombineInstance> coms = new List<CombineInstance>();
coms.Add(combine);
combines[mat.name] = coms;
}
 
Destroy(meshFilters[i].gameObject);
}
GameObject combineObj = new GameObject("Combine");
combineObj.transform.parent = transform;
foreach (KeyValuePair<string, Material> mater in materials)
{
GameObject obj = new GameObject(mater.Key);
obj.transform.parent = combineObj.transform;
MeshFilter combineMeshFilter = obj.AddComponent<MeshFilter>();
combineMeshFilter.mesh = new Mesh();
 
//將引用相同材質球的網格合併;
combineMeshFilter.mesh.CombineMeshes(combines[mater.Key].ToArray(), true,true);
MeshRenderer rend = obj.AddComponent<MeshRenderer>();
 
//指定材質球;
rend.sharedMaterial = mater.Value;
rend.castShadows = false;
rend.receiveShadows = true;
}
}
}