此次项目场景中有相当多的类似小方块的建筑简模（约13w个），每一个都是单独的存在，所以将场景中的所有建筑简模，按照区域划分，并合并网格，减轻了渲染负担，同时按区块合并，方便后续LOD等优化措施。

 [MenuItem("Tool/Combine Mesh With Area")]static void CombineMeshWithArea(){//当前选择的物体，必须为需要合并网格的物体的父物体GameObject selectedGo = Selection.activeGameObject;MeshFilter[] meshFilters = selectedGo.GetComponentsInChildren<MeshFilter>();selectedGo.SetActive(false);Transform parent = new GameObject("model").transform;parent.position = Vector3.zero;//x和z方向上划分的区块个数int areaNum_x = 100, areaNum_z = 100;//x和z方向的边界坐标float min_x=0,min_z=0,max_x=0,max_z = 0;//每个区块的长度float areaLength_x = 0,areaLength_z = 0;Vector3 tempPosition = Vector3.zero;Dictionary<string, List<MeshFilter>> areaMeshFilters = new Dictionary<string, List<MeshFilter>>();//取到最边界的范围for(int i = 0; i < meshFilters.Length; i++){tempPosition = meshFilters[i].transform.position;max_x = tempPosition.x > max_x ? tempPosition.x : max_x;min_x = tempPosition.x < min_x ? tempPosition.x : min_x;max_z = tempPosition.z > max_z ? tempPosition.z : max_z;min_z = tempPosition.z < min_z ? tempPosition.z : min_z;}areaLength_x = (max_x - min_x)/ areaNum_x;areaLength_z = (max_z - min_z)/ areaNum_z;//将所有物体划分至对应的区块中for (int i = 0; i < meshFilters.Length; i++){int tempX = (int)((meshFilters[i].transform.position.x - min_x) / areaLength_x);int tempZ = (int)((meshFilters[i].transform.position.z - min_z) / areaLength_z);string key = tempX + "," + tempZ;if (areaMeshFilters.ContainsKey(key)){areaMeshFilters[key].Add(meshFilters[i]);}else{List<MeshFilter> tempFilterList = new List<MeshFilter>();tempFilterList.Add(meshFilters[i]);areaMeshFilters.Add(key, tempFilterList);}}Debug.Log(areaMeshFilters.Count);//遍历所有区块，并合并网格foreach (string item in areaMeshFilters.Keys){List<MeshFilter> value = areaMeshFilters[item];CombineInstance[] combineInstances = new CombineInstance[value.Count];for (int i = 0; i < value.Count; i++){combineInstances[i].mesh = value[i].sharedMesh;combineInstances[i].transform = value[i].transform.localToWorldMatrix;}//新网格对象Mesh tempNewMesh = new Mesh();tempNewMesh.name = item;//将combineInstances数组传入函数tempNewMesh.CombineMeshes(combineInstances);//给当前空物体，添加网格组件；将合并后的网格，给到自身网格GameObject tempGo = new GameObject(item);tempGo.transform.parent = parent;tempGo.gameObject.AddComponent<MeshFilter>().sharedMesh = tempNewMesh;//给当前空物体添加渲染组件，给新模型网格上色;       tempGo.gameObject.AddComponent<MeshRenderer>().sharedMaterial = Resources.Load<Material>("Materials/FrontCol");}}

完成后的效果：   

合并完成后，可以设置合并后的网格中心点到模型中心，具体见：https://blog.csdn.net/weixin_39562801/article/details/107842345