Unity合并mesh，【CombineMeshes】将多个物体合并成一个物体或层级关系的物体

痛定思痛。 2023-09-23 12:58 76阅读 0赞

## Unity3D将多个物体合并一个物体或层级关系的物体 ##

### 一、三种合并工具 ###

#### 1.MergeMesh1： ####

（效率低，适应性高）模型点超过65535自动分模型，一个mesh上有多个材质会自动分出来成为子集部分，父节点要有mesh则 fatherMesh = true;

#### 2.MergeMesh2： ####

（效率快、适应性低）模型点不能超过65535，超过会报错，且相同材质才会合并，若一个mesh上有多个材质会少一些材质（也就是丢失了一部分模型）

#### 3.MergeMesh4： ####

（适应性极低）模型点不能超过65535，超过会报错 ，材质相同也不会合并(一般外部不常调用，MergeMesh1、2函数更好)

using System.Collections;
    using System.Collections.Generic;
    using UnityEngine;
    
    namespace CombineMeshes
    {
        ///<summary>
        ///注意：MergeMesh2、3只能针对于mesh上只有一个材质
        /// </summary>
        public static class Combinemeshes
        {
            /// <summary>
            /// （效率低，适应性高）模型点超过65535自动分模型，一个mesh上有多个材质会分出来成为子集部分，父节点要有mesh则 fatherMesh = true;
            /// </summary>
            public static GameObject MergeMesh1(GameObject parent, bool fatherMesh = true)
            {
                //获取原始坐标
                Vector3 initialPos = parent.transform.position;
                Quaternion initialRot = parent.transform.rotation;
                //将模型坐标归零
                parent.transform.position = Vector3.zero;
                parent.transform.rotation = Quaternion.Euler(Vector3.zero);
    
                List<GameObject> list = new List<GameObject>();
                int verts = 0;
                //存放要合并的父物体  
                Dictionary<int, GameObject> NewParent = new Dictionary<int, GameObject>();
                //获取所有网格过滤器
                MeshFilter[] meshFilters = parent.GetComponentsInChildren<MeshFilter>();
    
                //通过游戏对象的总点数/65536，进行分组
                for (int i = 0; i < meshFilters.Length; i++)
                {
                    verts += meshFilters[i].mesh.vertexCount;
                }
                for (int i = 1; i <= (verts / 65536) + 1; i++)
                {
                    GameObject wx = new GameObject("child" + i);
                    wx.transform.parent = parent.transform;
                    NewParent.Add(i, wx);
                }
                verts = 0;
                int key = 1;
                //给超过65535点的游戏对象进行分组
                for (int i = 0; i < meshFilters.Length; i++)
                {
                    verts += meshFilters[i].mesh.vertexCount;
                    if (verts >= 65535)
                    {
                        key++;
                        verts = 0;
                        verts += meshFilters[i].mesh.vertexCount;
                    }
                    //key= (verts / 65536) + 1;
                    if (NewParent.ContainsKey(key))
                    {
                        meshFilters[i].transform.parent = NewParent[key].transform;
                    }
                    //else
                    //    Debug.Log("错误");
                }
                //处理多材质（一个mesh上有多个材质）
                if (meshFilters[0].GetComponent<MeshRenderer>().sharedMaterials.Length > 1)
                {
                    list.Add(GameObject.Instantiate(meshFilters[0].gameObject));
                }
                //
                foreach (var item in NewParent)
                {
                    list.Add(MergeMesh3(item.Value, false));
                }
                //处理多材质
                for (int i = 1; i < meshFilters.Length; i++)
                {
                    if (meshFilters[0].GetComponent<MeshRenderer>().sharedMaterials.Length > 1)
                    {
                        for (int j = 0; j < list[0].transform.childCount; j++)
                        {
                            GameObject.Destroy(list[0].transform.GetChild(j).gameObject);
                        }
                        GameObject.Destroy(meshFilters[0].gameObject);
                    }
                    if (meshFilters[i].GetComponent<MeshRenderer>().sharedMaterials.Length > 1)
                    {
                        list.Add(GameObject.Instantiate(meshFilters[i].gameObject));
                        GameObject.Destroy(meshFilters[i].gameObject);
                    }
                }
                //
    
                GameObject tar_Obj = null;
                //是否父节点上有mesh
                if (!fatherMesh)
                {
                    tar_Obj = new GameObject();
                    tar_Obj.name = "clone_F";
                    for (int i = 0; i < list.Count; i++)
                    {
                        list[i].gameObject.transform.parent = tar_Obj.transform;
                    }
                    //还原坐标
                    tar_Obj.transform.position = initialPos;
                    tar_Obj.transform.rotation = initialRot;
                }
                //父节点上无mesh
                else
                {
                    for (int i = 1; i < list.Count; i++)
                    {
                        list[i].gameObject.transform.parent = list[0].gameObject.transform;
                        list[i].gameObject.name = "child" + i;
                    }
                    //还原坐标
                    list[0].gameObject.transform.position = initialPos;
                    list[0].gameObject.transform.rotation = initialRot;
                }
    
                GameObject.Destroy(parent);
                return fatherMesh ? list[0] : tar_Obj;
            }
            /// <summary>
            ///（效率快、适用性低）模型点不能超过65535，且相同材质会合并
            /// </summary>
            public static GameObject MergeMesh2(GameObject parent, bool mergeAll = true)
            {
                //获取原始坐标
                Vector3 initialPos = parent.transform.position;
                Quaternion initialRot = parent.transform.rotation;
                //将坐标归零
                parent.transform.position = Vector3.zero;
                parent.transform.rotation = Quaternion.Euler(Vector3.zero);
                //获取所有网格过滤器
                MeshFilter[] meshFilters = parent.GetComponentsInChildren<MeshFilter>();
                //存放不同的材质球，相同的就存一个
                Dictionary<string, Material> materials = new Dictionary<string, Material>();
    
                //存放要合并的网格对象
                Dictionary<string, List<CombineInstance>> combines = new Dictionary<string, List<CombineInstance>>();
                for (int i = 0; i < meshFilters.Length; i++)
                {
                    //构造一个网格合并结构体
                    CombineInstance combine = new CombineInstance();
    
                    //给结构体的mesh赋值
                    combine.mesh = meshFilters[i].sharedMesh;
                    combine.transform = meshFilters[i].transform.localToWorldMatrix;
    
                    MeshRenderer renderer = meshFilters[i].GetComponent<MeshRenderer>();
                    if (renderer == null)
                    {
                        continue;
                    }
                    Material mat = renderer.sharedMaterial;
                    //将相同材质记录一次，再将拥有相同材质的mesh放到Dictionary中
                    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;
                    }
                }
                GameObject combineObj = new GameObject(parent.name);
                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();
    
                    //将引用相同材质球的网格合并
                    combineMeshFilter.sharedMesh.CombineMeshes(combines[mater.Key].ToArray(), true, true);
                    //Debug.LogError("网格定点数" + combineMeshFilter.sharedMesh.vertices);
                    MeshRenderer rend = obj.AddComponent<MeshRenderer>();
    
                    //指定材质球
                    rend.sharedMaterial = mater.Value;
    
                    //需要设置请自行打开
                    //rend.shadowCastingMode = ShadowCastingMode.Off;
                    //rend.receiveShadows = true;
                }
    
                GameObject tar_Obj = null;
                if (mergeAll)
                {
                    tar_Obj = MergeMesh3(combineObj);
                }
                //还原坐标
                tar_Obj.transform.position = initialPos;
                tar_Obj.transform.rotation = initialRot;
                GameObject.Destroy(parent);
                return tar_Obj;
            }
            /// <summary>
            /// 模型点不能超过65535，材质相同也不会合并(一般外部不常调用，MergeMesh1、2函数更好)
            /// </summary>
            public static GameObject MergeMesh3(GameObject parent, bool mergeSubMeshes = false)
            {
                MeshRenderer[] meshRenderers = parent.GetComponentsInChildren<MeshRenderer>();
                Material[] materials = new Material[meshRenderers.Length];
                for (int i = 0; i < meshRenderers.Length; i++)
                {
                    materials[i] = meshRenderers[i].sharedMaterial;
                }
    
                MeshFilter[] meshFilters = parent.GetComponentsInChildren<MeshFilter>();
                CombineInstance[] combineInstances = new CombineInstance[meshFilters.Length];
                for (int i = 0; i < meshFilters.Length; i++)
                {
                    combineInstances[i].mesh = meshFilters[i].sharedMesh;
                    combineInstances[i].transform = meshFilters[i].transform.localToWorldMatrix;
                }
                GameObject mesh_obj = new GameObject(parent.name);
    
                MeshFilter meshFilter = mesh_obj.AddComponent<MeshFilter>();
                meshFilter.mesh.CombineMeshes(combineInstances, mergeSubMeshes);
                MeshRenderer meshRenderer = mesh_obj.AddComponent<MeshRenderer>();
                meshRenderer.sharedMaterials = materials;
    
                GameObject.Destroy(parent);
                return mesh_obj;
            }
        }
    }

### 二、调用合并工具 ###

using System.Collections.Generic;
    using UnityEngine;
    using CombineMeshes;
    public class UsingMergeMesh : MonoBehaviour
    {
        [Header("示例1：AllMergeMesh")]
        public GameObject MergeMeshGameObject;
        [Header("示例2：PartMergeMesh请给父节点放入4个模型（若没有4个游戏对象，程序会报错）")]
        public GameObject MergeMeshGameObject2;//
    
        void Update()
        {
            //按下Enter键才会执行
            if (Input.GetKeyDown(KeyCode.Return))
            {
                AllMergeMesh(MergeMeshGameObject);
            }
            //按下A键才会执行
            if (Input.GetKeyDown(KeyCode.A))
            {
                PartMergeMesh(MergeMeshGameObject2);
            }
        }
    
        /// <summary>
        /// 模型的整体合并网格
        /// </summary>
        /// <param name="source_Obj">父节点</param>
        /// <returns></returns>
        GameObject AllMergeMesh(GameObject source_Obj)
        {
            Vector3 initialPos = source_Obj.transform.position;
            Quaternion initialRot = source_Obj.transform.rotation;
    
            GameObject clone_Obj = Instantiate(source_Obj);
            GameObject cloneParents = new GameObject();
            cloneParents.transform.position = initialPos;
            cloneParents.transform.rotation = initialRot;
    
            clone_Obj.transform.parent = cloneParents.transform;
            #region<根据实际要求自行更改>
            ///<summary>
            ///自动分总点数超过65535点的模型，超过65535的点会有子集关系，且相同材质会合并
            ///</summary>
            GameObject tar_Obj = Combinemeshes.MergeMesh1(cloneParents, true);//父节点有mesh
            //tar_Obj = Combinemeshes.MergeMesh1(clone_F,false);//父节点无mesh
    
    
            ///<summary>
            ///模型总点数不能超过65535，且相同材质会合并，超过会报错：合并游戏对象的总点数超过65535
            ///</summary>
            //tar_Obj = Combinemeshes.MergeMesh2(clone_F);
    
    
            ///<summary>
            ///模型总点数不能超过65535，材质相同也不会合并（一般不调用，MergeMesh2函数更好）
            ///</summary>
            //tar_Obj = Combinemeshes.MergeMesh3(clone_F);
            #endregion
    
            tar_Obj.name = "AllMergeMesh";
            return tar_Obj;
        }
    
        /// <summary>
        /// 模型的子集关系合并（这里做个示例，请给父节点放入4个模型）
        /// </summary>
        /// <param name="source_Obj">父节点</param>
        /// <returns></returns>
        GameObject PartMergeMesh(GameObject source_Obj)
        {
            //获取父节点中的子物体
            List<GameObject> source_ObjChild = new List<GameObject>();
            for (int i = 0; i < source_Obj.transform.childCount; i++)
            {
                source_ObjChild.Add(source_Obj.transform.GetChild(i).gameObject);
            }
            GameObject tar_Obj = new GameObject(source_Obj.name);
    
            GameObject gameObjects;//将gameObj实例化的对象，放入gameObjects子集中
            List<GameObject> gameObj = new List<GameObject>();//实例化对象
    
            //合并一
            gameObjects = new GameObject(source_Obj.name);
            gameObjects.transform.position = source_ObjChild[0].transform.localPosition;
            gameObj.Add(Instantiate(source_ObjChild[0]));
            gameObj.Add(Instantiate(source_ObjChild[1]));
            for (int i = 0; i < gameObj.Count; i++)
            {
                gameObj[i].transform.parent = gameObjects.transform;
            }
            //这里我用的是MergeMesh1，可自行根据实际更改MergeMesh2、MergeMesh3
            gameObjects = Combinemeshes.MergeMesh1(gameObjects);
            gameObj.Clear();
            gameObjects.transform.parent = tar_Obj.transform;
    
            //合并二
            gameObjects = new GameObject("joint");
            gameObjects.transform.position = source_ObjChild[2].transform.localPosition;
            gameObj.Add(Instantiate(source_ObjChild[2]));
            gameObj.Add(Instantiate(source_ObjChild[3]));
            for (int i = 0; i < gameObj.Count; i++)
            {
                gameObj[i].transform.parent = gameObjects.transform;
            }
            //这里我用的是MergeMesh1，可自行根据实际更改MergeMesh2、MergeMesh3
            gameObjects = Combinemeshes.MergeMesh1(gameObjects);
            gameObj.Clear();
            gameObjects.transform.parent = tar_Obj.transform;
    
    
            Vector3 initialPos = source_Obj.transform.position;
            Quaternion initialRot = source_Obj.transform.rotation;
    
            tar_Obj.transform.position = initialPos;
            tar_Obj.transform.rotation = initialRot;
    
            //设置父子关系
            for (int i = 0; i < tar_Obj.transform.childCount; i++)
            {
                gameObj.Add(tar_Obj.transform.GetChild(i).gameObject);
            }
            for (int i = 1; i < gameObj.Count; i++)
            {
                gameObj[i].transform.parent = gameObj[i - 1].transform;
            }
    
            #region<根据需要请自行更改>
            ///<summary>
            ///父节点有mesh
            /// </summary>
            gameObj[0].transform.parent = tar_Obj.transform.parent;
            gameObj[0].name = "PartMergeMesh";
            Destroy(tar_Obj);
            return gameObj[0];
    
            ///<summary>
            ///父节点无mesh
            /// </summary>
            //return tar_Obj;
            #endregion
        }
    
    }

### 三、使用方法 ###

#### 1.创建如下测试示例模型，拖入框中 ####

![a9267bfad4004ecda1ef3eaa87ebb478.png][]

#### 2.创建好的模型如下![0044383de4e347aeaae8080cf7cad026.png][] ####

#### 3.点击Enter和A键就会得到如下合并后的模型，合并后模型与原模型位置是重合的，为了方便大家看清合并的模型，我将它们移了出来。 ####

![8c81bb53f0a94cab9085a803360312b8.png][]

参考文章：

[Unity 合并Mesh 将多个小的物体合并成一个大物体，同批次渲染\_万兴丶的博客-CSDN博客\_unity合并物体][Unity _Mesh _-CSDN_unity]

[a9267bfad4004ecda1ef3eaa87ebb478.png]: https://img-blog.csdnimg.cn/a9267bfad4004ecda1ef3eaa87ebb478.png
[0044383de4e347aeaae8080cf7cad026.png]: https://img-blog.csdnimg.cn/0044383de4e347aeaae8080cf7cad026.png
[8c81bb53f0a94cab9085a803360312b8.png]: https://img-blog.csdnimg.cn/8c81bb53f0a94cab9085a803360312b8.png
[Unity _Mesh _-CSDN_unity]: https://blog.csdn.net/qq_42980269/article/details/123064307