Unity --- MeshRenderer之网格合并

创建如图所示的对象结构,parent为空对象，然后将下面的代码挂载到parent对象上运行即可。

 using UnityEngine;
 using System.Collections;

 public class CombineMeshAndMaterials : MonoBehaviour
 {
     void Start()
     {
         CombineMesh();
     }
     void CombineMesh()
     {
         //收集要合并的贴图
         MeshRenderer[] oldMRArray = GetComponentsInChildren<MeshRenderer>();
         Material[] oldMArray = new Material[oldMRArray.Length];
         Texture2D[] textures = new Texture2D[oldMRArray.Length];
         for (int i = , iMax = oldMRArray.Length; i < iMax; ++i)
         {
             oldMArray[i] = oldMRArray[i].sharedMaterial;
             Texture2D t2d = oldMArray[i].GetTexture("_MainTex") as Texture2D;
             Texture2D _t2d = new Texture2D(t2d.width, t2d.height, TextureFormat.ARGB32, false);
             _t2d.SetPixels(t2d.GetPixels(, , t2d.width, t2d.height));
             _t2d.Apply();
             textures[i] = _t2d;
         }

         //创建合并后的材质
         MeshRenderer newMR = gameObject.AddComponent<MeshRenderer>();
         Material newM = new Material(oldMArray[].shader);
         newM.CopyPropertiesFromMaterial(oldMArray[]);
         newMR.sharedMaterial = newM;

         //创建合并后的贴图，
         Texture2D newTex = new Texture2D(, );
         newM.SetTexture("_MainTex", newTex);   //将合并后的贴图赋给合并后的材质

         //重新计算贴图UV
         MeshFilter[] oldMF = GetComponentsInChildren<MeshFilter>();
         CombineInstance[] combines = new CombineInstance[oldMF.Length];
         Rect[] rects = newTex.PackTextures(textures, , );  //贴图打包 ，矩形的数组包含每个输入的纹理的UV坐标
         for (int i = , iMax = oldMF.Length; i < iMax; ++i)
         {
             Rect rect = rects[i];
             Mesh mesh = oldMF[i].mesh;
             Vector2[] newUVs = new Vector2[mesh.uv.Length];

             //刷新uv
             for (int j = , jMax = mesh.uv.Length; j < jMax; ++j)
             {
                 //如果这里看不太懂，说明对uv的确切含义不太明白
                 //uv是一个比值,u = 横向第u个像素/原始贴图的宽度    v = 竖向第v个像素/原始贴图的高度
                 //rect.x : 原贴图在合并后的贴图的 x 坐标，  rect.y : 原贴图在合并后的贴图的 y 坐标
                 newUVs[j].x = mesh.uv[j].x * rect.width + rect.x;
                 newUVs[j].y = mesh.uv[j].y * rect.height + rect.y;
             }
             mesh.uv = newUVs;
             combines[i].mesh = mesh;
             combines[i].transform = oldMF[i].transform.localToWorldMatrix;  //没有这句,合并后的网格无法看到
             oldMF[i].gameObject.SetActive(false);
         }

         //创建合并后的网格
         MeshFilter newMF = gameObject.AddComponent<MeshFilter>();
         Mesh newMesh = new Mesh();
         newMesh.CombineMeshes(combines, true, true);
         newMF.mesh = newMesh;
     }
 }