一、前言

美术想要一个把unity中*.asset的模型导出来，导成3D Max可以打开的模式，fbx或obj. 

需要导出的格式：

图1

也就是需要一个工具，个人觉得这个问题，肯定之前Unity的前辈就有解决方法了。于是乎网上一通下载和测试。

二、解包工具集合

网络上找来了各种测试，但是没有一个适合我的，很多都是失败，打不开。 
参考宣雨松的博客，找了还是没有结果。

 解包工具有很多种类， 
disunity github地址: https://github.com/ata4/disunity 

还有就是AssetAssetsExport，还有Unity Studio. 
别人的博客里面都有比较多的介绍和说明，这里就详细说了。 

最后还网上wiki里，找到了一个合适的我自己的解包。 
//wiki.unity3d.com/index.php?title=ObjExporter

三、初步成果

找到了一个网站：//wiki.unity3d.com/index.php?title=ObjExporter 

可以导出部分对象。 

而原来unity中模型是这个样子的。

导出的只有武器和头盔，没有人物主体body.

四、bug修改

其实也不能算bug，也许人家没有这样的需要呢。

 Component[] meshfilter = selection[i].GetComponentsInChildren<MeshFilter>();

            MeshFilter[] mf = new MeshFilter[meshfilter.Length];

            int m = 0;

            for (; m < meshfilter.Length; m++)

            {

                exportedObjects++;

                mf[m] = (MeshFilter)meshfilter[m];

            }

代码中是要查找所有组件中的MeshFilter，发现SkinnedMeshRender组件居然没有这个MeshFilter这个组件，所以总会导出少一个，而这个居然是人的主体。

本来说让美术自己添加一个MeshFilter组件，然后根据mesh render中的mesh自己来添加一个对应的mesh. 

既然是程序，那就想办法，思路很明显，既然是有meshrender,就从这入手呗。 

代码还是不难度。

// 没有meshFilter，添加一个meshFilter.

            SkinnedMeshRenderer[] meshfilterRender = selection[i].GetComponentsInChildren<SkinnedMeshRenderer>();

            for (int j = 0; j < meshfilterRender.Length; j++)

            {   

                if (meshfilterRender[j].GetComponent<MeshFilter>() == null)

                {

                    meshfilterRender[j].gameObject.AddComponent<MeshFilter>();

                    meshfilterRender[j].GetComponent<MeshFilter>().sharedMesh = Instantiate(meshfilterRender[j].sharedMesh);

                }

            }

这样修改过，就会自动在没有MeshFilter，但是有skinnedMeshRender组件的节点下，添加一个MeshFilter,然后就可以正常导出成.obj文件，与.FBX是类似的，都可以被3D max编辑使用。

最后的在VS中看的模型，因为没有安装3Dmax.

虽然看起来简陋，但是满足他们小需要，就好了。 

贴出主要的代码：

/*

Based on ObjExporter.cs, this "wrapper" lets you export to .OBJ directly from the editor menu.

This should be put in your "Editor"-folder. Use by selecting the objects you want to export, and select

the appropriate menu item from "Custom->Export". Exported models are put in a folder called

"ExportedObj" in the root of your Unity-project. Textures should also be copied and placed in the

same folder.

N.B. there may be a bug so if the custom option doesn't come up refer to this thread //answers.unity3d.com/questions/317951/how-to-use-editorobjexporter-obj-saving-script-fro.html

Updated for Unity 5.3

2017-03-07

@cartzhang

fixed can not create obj file in folder.

*/

using UnityEngine;using UnityEditor;using UnityEditor.SceneManagement;using System.Collections;using System.Collections.Generic;using System.IO;using System.Text;using System;

struct ObjMaterial

{

    public string name;

    public string textureName;

}

public class EditorObjExporter : ScriptableObject

{

    private static int vertexOffset = 0;

    private static int normalOffset = 0;

    private static int uvOffset = 0;

    //User should probably be able to change this. It is currently left as an excercise for

    //the reader.

    private static string targetFolder = "ExportedObj";

    private static string MeshToString(MeshFilter mf, Dictionary<string, ObjMaterial> materialList)

    {

        Debug.Assert(null != mf);

        Mesh m = mf.sharedMesh;

        Material[] mats = mf.GetComponent<Renderer>().sharedMaterials;

        StringBuilder sb = new StringBuilder();

        if (null == m)

            return sb.ToString();

        sb.Append("g ").Append(mf.name).Append("\n");

        foreach (Vector3 lv in m.vertices)

        {

            Vector3 wv = mf.transform.TransformPoint(lv);

            //This is sort of ugly - inverting x-component since we're in

            //a different coordinate system than "everyone" is "used to".

            sb.Append(string.Format("v {0} {1} {2}\n", -wv.x, wv.y, wv.z));

        }

        sb.Append("\n");

        foreach (Vector3 lv in m.normals)

        {

            Vector3 wv = mf.transform.TransformDirection(lv);

            sb.Append(string.Format("vn {0} {1} {2}\n", -wv.x, wv.y, wv.z));

        }

        sb.Append("\n");

        foreach (Vector3 v in m.uv)

        {

            sb.Append(string.Format("vt {0} {1}\n", v.x, v.y));

        }

        for (int material = 0; material < m.subMeshCount; material++)

        {

            sb.Append("\n");

            sb.Append("usemtl ").Append(mats[material].name).Append("\n");

            sb.Append("usemap ").Append(mats[material].name).Append("\n");

            //See if this material is already in the materiallist.

            try

            {

                ObjMaterial objMaterial = new ObjMaterial();

                objMaterial.name = mats[material].name;

                if (mats[material].mainTexture)

                    objMaterial.textureName = AssetDatabase.GetAssetPath(mats[material].mainTexture);

                else

                    objMaterial.textureName = null;

                materialList.Add(objMaterial.name, objMaterial);

            }

            catch (ArgumentException)

            {

                //Already in the dictionary

            }

            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 + vertexOffset, triangles[i + 1] + 1 + normalOffset, triangles[i + 2] + 1 + uvOffset));

            }

        }

        vertexOffset += m.vertices.Length;

        normalOffset += m.normals.Length;

        uvOffset += m.uv.Length;

        return sb.ToString();

    }

    private static void Clear()

    {

        vertexOffset = 0;

        normalOffset = 0;

        uvOffset = 0;

    }

    private static Dictionary<string, ObjMaterial> PrepareFileWrite()

    {

        Clear();

        return new Dictionary<string, ObjMaterial>();

    }

    private static void MaterialsToFile(Dictionary<string, ObjMaterial> materialList, string folder, string filename)

    {

        using (StreamWriter sw = new StreamWriter(folder + Path.DirectorySeparatorChar + filename + ".mtl"))

        {

            foreach (KeyValuePair<string, ObjMaterial> kvp in materialList)

            {

                sw.Write("\n");

                sw.Write("newmtl {0}\n", kvp.Key);

                sw.Write("Ka  0.6 0.6 0.6\n");

                sw.Write("Kd  0.6 0.6 0.6\n");

                sw.Write("Ks  0.9 0.9 0.9\n");

                sw.Write("d  1.0\n");

                sw.Write("Ns  0.0\n");

                sw.Write("illum 2\n");

                if (kvp.Value.textureName != null)

                {

                    string destinationFile = kvp.Value.textureName;

                    int stripIndex = destinationFile.LastIndexOf(Path.DirectorySeparatorChar);

                    if (stripIndex >= 0)

                        destinationFile = destinationFile.Substring(stripIndex + 1).Trim();

                    string relativeFile = destinationFile;

                    destinationFile = folder + Path.DirectorySeparatorChar + destinationFile;

                    Debug.Log("Copying texture from " + kvp.Value.textureName + " to " + destinationFile);

                    try

                    {

                        //Copy the source file

                        File.Copy(kvp.Value.textureName, destinationFile);

                    }

                    catch

                    {

                    }

                    sw.Write("map_Kd {0}", relativeFile);

                }

                sw.Write("\n\n\n");

            }

        }

    }

    private static void MeshToFile(MeshFilter mf, string folder, string filename)

    {

        Dictionary<string, ObjMaterial> materialList = PrepareFileWrite();

        using (StreamWriter sw = new StreamWriter(folder + Path.DirectorySeparatorChar + filename + ".obj"))

        {

            sw.Write("mtllib ./" + filename + ".mtl\n");

            sw.Write(MeshToString(mf, materialList));

        }

        MaterialsToFile(materialList, folder, filename);

    }

    private static void MeshesToFile(MeshFilter[] mf, string folder, string filename)

    {

        Dictionary<string, ObjMaterial> materialList = PrepareFileWrite();

        using (StreamWriter sw = new StreamWriter(folder + Path.DirectorySeparatorChar + filename + ".obj"))

        {

            sw.Write("mtllib ./" + filename + ".mtl\n");

            for (int i = 0; i < mf.Length; i++)

            {

                sw.Write(MeshToString(mf[i], materialList));

            }

        }

        MaterialsToFile(materialList, folder, filename);

    }

    private static bool CreateTargetFolder()

    {

        try

        {

            System.IO.Directory.CreateDirectory(targetFolder);

        }

        catch

        {

            EditorUtility.DisplayDialog("Error!", "Failed to create target folder!", "");

            return false;

        }

        return true;

    }

    [MenuItem("Custom/Export/Export whole selection to single OBJ")]

    static void ExportWholeSelectionToSingle()

    {

        if (!CreateTargetFolder())

            return;

        Transform[] selection = Selection.GetTransforms(SelectionMode.Editable | SelectionMode.ExcludePrefab);

        if (selection.Length == 0)

        {

            EditorUtility.DisplayDialog("No source object selected!", "Please select one or more target objects", "");

            return;

        }

        int exportedObjects = 0;

        ArrayList mfList = new ArrayList();

        for (int i = 0; i < selection.Length; i++)

        {

            Component[] meshfilter = selection[i].GetComponentsInChildren(typeof(MeshFilter));

            for (int m = 0; m < meshfilter.Length; m++)

            {

                exportedObjects++;

                mfList.Add(meshfilter[m]);

            }

        }

        if (exportedObjects > 0)

        {

            MeshFilter[] mf = new MeshFilter[mfList.Count];

            for (int i = 0; i < mfList.Count; i++)

            {

                mf[i] = (MeshFilter)mfList[i];

            }

            string filename = EditorSceneManager.GetActiveScene().name + "_" + exportedObjects;

            int stripIndex = filename.LastIndexOf(Path.DirectorySeparatorChar);

            if (stripIndex >= 0)

                filename = filename.Substring(stripIndex + 1).Trim();

            MeshesToFile(mf, targetFolder, filename);

            EditorUtility.DisplayDialog("Objects exported", "Exported " + exportedObjects + " objects to " + filename, "");

        }

        else

            EditorUtility.DisplayDialog("Objects not exported", "Make sure at least some of your selected objects have mesh filters!", "");

    }

    [MenuItem("Custom/Export/Export each selected to single OBJ")]

    static void ExportEachSelectionToSingle()

    {

        if (!CreateTargetFolder())

            return;

        Transform[] selection = Selection.GetTransforms(SelectionMode.Editable | SelectionMode.ExcludePrefab);

        if (selection.Length == 0)

        {

            EditorUtility.DisplayDialog("No source object selected!", "Please select one or more target objects", "");

            return;

        }

        int exportedObjects = 0;

        for (int i = 0; i < selection.Length; i++)

        {

            // 没有meshFilter，添加一个meshFilter.

            SkinnedMeshRenderer[] meshfilterRender = selection[i].GetComponentsInChildren<SkinnedMeshRenderer>();

            for (int j = 0; j < meshfilterRender.Length; j++)

            {   

                if (meshfilterRender[j].GetComponent<MeshFilter>() == null)

                {

                    meshfilterRender[j].gameObject.AddComponent<MeshFilter>();

                    meshfilterRender[j].GetComponent<MeshFilter>().sharedMesh = Instantiate(meshfilterRender[j].sharedMesh);

                }

            }

            Component[] meshfilter = selection[i].GetComponentsInChildren<MeshFilter>();

            MeshFilter[] mf = new MeshFilter[meshfilter.Length];

            int m = 0;

            for (; m < meshfilter.Length; m++)

            {

                exportedObjects++;

                mf[m] = (MeshFilter)meshfilter[m];

            }

            MeshesToFile(mf, targetFolder, selection[i].name + "_" + i);

        }

        if (exportedObjects > 0)

        {

            EditorUtility.DisplayDialog("Objects exported", "Exported " + exportedObjects + " objects", "");

        }

        else

            EditorUtility.DisplayDialog("Objects not exported", "Make sure at least some of your selected objects have mesh filters!", "");

    }

}

可以直接复制到直接的项目中使用。

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