Unity --- MeshRenderer之網格合并

創建如圖所示的對象結構,parent為空對象，然后將下面的代碼掛載到parent對象上運行即可。

using UnityEngine;
using System.Collections;

public class CombineMeshAndMaterials : MonoBehaviour
{
    void Start()
    {
        CombineMesh();
    }
    void CombineMesh()
    {
        //收集要合并的貼圖
        MeshRenderer[] oldMRArray = GetComponentsInChildren<MeshRenderer>();
        Material[] oldMArray = new Material[oldMRArray.Length];
        Texture2D[] textures = new Texture2D[oldMRArray.Length];
        for (int i = 0, 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(0, 0, t2d.width, t2d.height));
            _t2d.Apply();
            textures[i] = _t2d;
        }

        //創建合并后的材質
        MeshRenderer newMR = gameObject.AddComponent<MeshRenderer>();
        Material newM = new Material(oldMArray[0].shader);
        newM.CopyPropertiesFromMaterial(oldMArray[0]);
        newMR.sharedMaterial = newM;

        //創建合并后的貼圖，
        Texture2D newTex = new Texture2D(1024, 1024);
        newM.SetTexture("_MainTex", newTex);   //將合并后的貼圖賦給合并后的材質

        //重新計算貼圖UV
        MeshFilter[] oldMF = GetComponentsInChildren<MeshFilter>();
        CombineInstance[] combines = new CombineInstance[oldMF.Length];
        Rect[] rects = newTex.PackTextures(textures, 10, 1024);  //貼圖打包 ，矩形的數組包含每個輸入的紋理的UV坐標
        for (int i = 0, 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 = 0, jMax = mesh.uv.Length; j < jMax; ++j)
            {
                //如果這里看不太懂，說明對uv的確切含義不太明白
                //uv是一個比值,u = 橫向第u個像素/原始貼圖的寬度    v = 豎向第v個像素/原始貼圖的高度
                //rect.x : 原貼圖在合并后的貼圖的 x 坐標，  rect.y : 原貼圖在合并后的貼圖的 y 坐標
                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;  //沒有這句,合并后的網格無法看到
            oldMF[i].gameObject.SetActive(false);
        }

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