Unity批量生成Prefab

在項目中有時會遇到批量生成Prefab的需求。於是寫了一個編輯器，用來實現此功能。

在Hierarchy面板中選中多個GameObject，點擊生成Prefab即可。

如果所選物體中包含自定義Mesh，需要先在指定目錄生成Obj，再將Obj包含的網格賦值給新生成的Prefab。

編輯器腳本如下：

using UnityEngine;
using UnityEditor;
using System.Collections;
using System.IO;
/// <summary>
/// CreatePrefabs類為批量創建Prefab的窗口類，選擇Hierarchy窗口的物體，點擊創建Prefab即可在指定目錄生成Prefab
/// 如果所選物體含有動態創建的Mesh，必須先在指定目錄先生成OBJ文件
/// </summary>
public class CreatePrefabs : EditorWindow
{
    [MenuItem("AssetsManager/批量生成Prefab")]

    static void AddWindow()
    {
        //創建窗口
        CreatePrefabs window = (CreatePrefabs)EditorWindow.GetWindow(typeof(CreatePrefabs), false, "批量生成Prefab");
        window.Show();

    }

    //輸入文字的內容
    private string PrefabPath = "Assets/Resources/";
    private string ObjPath = @"Assets/Obj/";
    GameObject[] selectedGameObjects;



    [InitializeOnLoadMethod]
    public void Awake()
    {
        OnSelectionChange();
    }
    void OnGUI()
    {
        GUIStyle text_style = new GUIStyle();
        text_style.fontSize = 15;
        text_style.alignment = TextAnchor.MiddleCenter;

        EditorGUILayout.BeginHorizontal();
        GUILayout.Label("Prefab導出路徑:");
        PrefabPath = EditorGUILayout.TextField(PrefabPath);
        if (GUILayout.Button("瀏覽"))
        { EditorApplication.delayCall += OpenPrefabFolder; }
        EditorGUILayout.EndHorizontal();
        EditorGUILayout.BeginHorizontal();

        GUILayout.Label("    Obj導出路徑:");
        ObjPath = EditorGUILayout.TextField(ObjPath);
        if (GUILayout.Button("瀏覽"))
        { EditorApplication.delayCall += OpenObjFolder; }
        EditorGUILayout.EndHorizontal();

        GUILayout.Label("當前選中了" + selectedGameObjects.Length + "個物體", text_style);
        if (GUILayout.Button("如果包含動態創建的Mesh，請先點擊生成Obj", GUILayout.MinHeight(20)))
        {
            foreach (GameObject m in selectedGameObjects)
            {
                CreateObj(m);
            }
            AssetDatabase.Refresh();
        }
            if (GUILayout.Button("生成當前選中物體的Prefab", GUILayout.MinHeight(20)))
        {
            if (selectedGameObjects.Length <= 0)
            {
                //打開一個通知欄  
                this.ShowNotification(new GUIContent("未選擇所要導出的物體"));
                return;
            }
            if (!Directory.Exists(PrefabPath))
            {
                Directory.CreateDirectory(PrefabPath);
            }
            foreach (GameObject m in selectedGameObjects)
            {
                CreatePrefab(m, m.name);
            }
            AssetDatabase.Refresh();
        }
    }

    void OpenPrefabFolder()
    {
        string path = EditorUtility.OpenFolderPanel("選擇要導出的路徑", "", "");
        if (!path.Contains(Application.dataPath))
        {
            Debug.LogError("導出路徑應在當前工程目錄下");
            return;
        }
        if (path.Length != 0)
        {
            int firstindex = path.IndexOf("Assets");
            PrefabPath = path.Substring(firstindex) + "/";
            EditorUtility.FocusProjectWindow();
        }
    }

    void OpenObjFolder()
    {
        string path = EditorUtility.OpenFolderPanel("選擇要導出的路徑", "", "");
        if (!path.Contains(Application.dataPath))
        {
            Debug.LogError("導出路徑應在當前工程目錄下");
            return;
        }
        if (path.Length != 0)
        {
            int firstindex = path.IndexOf("Assets");
            ObjPath = path.Substring(firstindex) + "/";
            EditorUtility.FocusProjectWindow();
        }
    }

    void CreateObj(GameObject go)
    {
        if (!Directory.Exists(ObjPath))
        {
            Directory.CreateDirectory(ObjPath);
        }
        MeshFilter[] meshfilters = go.GetComponentsInChildren<MeshFilter>();
        if (meshfilters.Length > 0)
        {
            for (int i = 0; i < meshfilters.Length; i++)
            {
                ObjExporter.MeshToFile(meshfilters[i], ObjPath + meshfilters[i].gameObject.name + ".obj");

            }
        }
    }
    /// <summary>
    /// 此函數用來根據某物體創建指定名字的Prefab
    /// </summary>
    /// <param name="go">選定的某物體</param>
    /// <param name="name">物體名</param>
    /// <returns>void</returns>
    void CreatePrefab(GameObject go, string name)
    {  
        //先創建一個空的預制物體
        //預制物體保存在工程中路徑，可以修改("Assets/" + name + ".prefab");
        GameObject tempPrefab = PrefabUtility.CreatePrefab(PrefabPath + name + ".prefab", go);

        MeshFilter []meshfilters= go.GetComponentsInChildren<MeshFilter>();
        if (meshfilters.Length > 0)
        {
            MeshFilter[] prefabmeshfilters = tempPrefab.GetComponentsInChildren<MeshFilter>();
            for (int i = 0; i < meshfilters.Length; i++)
            {
               Mesh m_mesh = AssetDatabase.LoadAssetAtPath<Mesh>(ObjPath + meshfilters[i].gameObject.name + ".obj");
                prefabmeshfilters[i].sharedMesh = m_mesh;
            }
        }
        //返回創建后的預制物體
    }

    void OnInspectorUpdate()
    {
        //這里開啟窗口的重繪，不然窗口信息不會刷新
        this.Repaint();
    }

    void OnSelectionChange()
    {
        //當窗口出去開啟狀態，並且在Hierarchy視圖中選擇某游戲對象時調用
        selectedGameObjects = Selection.gameObjects;

    }
}

using UnityEngine;
using System.Collections;
using System.IO;
using System.Text;

public class ObjExporter
{

    public static string MeshToString(MeshFilter mf)
    {
        Mesh m = mf.sharedMesh;
        //  Material[] mats = mf.GetComponent<MeshRenderer>().sharedMaterials;

        StringBuilder sb = new StringBuilder();

        sb.Append("g ").Append(mf.name).Append("\n");
        for(int i=0;i<m.vertices.Length;i++)
            sb.Append(string.Format("v {0} {1} {2}\n", -m.vertices[i].x, m.vertices[i].y, m.vertices[i].z));
        sb.Append("\n");
        for (int i = 0; i < m.normals.Length; i++)
            sb.Append(string.Format("vn {0} {1} {2}\n", -m.normals[i].x, m.normals[i].y, m.normals[i].z));
        sb.Append("\n");
        for (int i = 0; i < m.uv.Length; i++)
            sb.Append(string.Format("vt {0} {1}\n",m.uv[i].x, m.uv[i].y));

        for (int material = 0; material < m.subMeshCount; material++)
        {
            sb.Append("\n");

            int[] triangles = m.GetTriangles(material);
            for (int i = 0; i < triangles.Length; i += 3)
            {
                //Because we inverted the x-component, we also needed to alter the triangle winding.
                sb.Append(string.Format("f {1}/{1}/{1} {0}/{0}/{0} {2}/{2}/{2}\n",
                    triangles[i] + 1, triangles[i + 1] + 1, triangles[i + 2] + 1));
            }
        }
        return sb.ToString();
    }

    public static void MeshToFile(MeshFilter mf, string filename)
{
    using (StreamWriter sw = new StreamWriter(filename))
    {
        sw.Write(MeshToString(mf));
    }
}
}