GSDObjExporter.cs

/*
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 
http://answers.unity3d.com/questions/317951/how-to-use-editorobjexporter-obj-saving-script-fro.html 
http://wiki.unity3d.com/index.php?title=ObjExporter
http://wiki.unity3d.com/index.php/User:KeliHlodversson
*/

#if UNITY_EDITOR
#region "Imports"
using UnityEngine;
using UnityEditor;
using System.Collections;
using System.Collections.Generic;
using System.IO;
using System.Text;
using System;
#endregion


struct ObjMaterial
{
    public string name;
    public string textureName;
}


public class GSDObjExporter : 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)
    {
        Mesh m = mf.sharedMesh;
        Renderer rend = mf.GetComponent<Renderer>();
        //Material[] mats = mf.renderer.sharedMaterials;
        Material[] mats = rend.sharedMaterials;

        StringBuilder sb = new StringBuilder();

        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 index = 0; index < triangles.Length; index += 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[index] + 1 + vertexOffset, triangles[index + 1] + 1 + normalOffset, triangles[index + 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 + "/" + 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('/');//FIXME: Should be Path.PathSeparator;

                    if (stripIndex >= 0)
                    {
                        destinationFile = destinationFile.Substring(stripIndex + 1).Trim();
                    }


                    string relativeFile = destinationFile;

                    destinationFile = folder + "/" + 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 + "/" + 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 + "/" + filename + ".obj"))
        {
            sw.Write("mtllib ./" + filename + ".mtl\n");

            for (int index = 0; index < mf.Length; index++)
            {
                sw.Write(MeshToString(mf[index], 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("Window/Road Architect/Export/Export all MeshFilters in selection to separate OBJs")]
    private static void ExportSelectionToSeparate()
    {
        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 index = 0; index < selection.Length; index++)
        {
            Component[] meshfilter = selection[index].GetComponentsInChildren(typeof(MeshFilter));

            for (int m = 0; m < meshfilter.Length; m++)
            {
                exportedObjects++;
                MeshToFile((MeshFilter) meshfilter[m], targetFolder, selection[index].name + "_" + index + "_" + m);
            }
        }

        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!", "");
        }
    }


    [MenuItem("Window/Road Architect/Export/Export whole selection to single OBJ")]
    private 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 index = 0; index < selection.Length; index++)
        {
            Component[] meshfilter = selection[index].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 index = 0; index < mfList.Count; index++)
            {
                mf[index] = (MeshFilter) mfList[index];
            }


            string tSceneName = UnityEditor.SceneManagement.EditorSceneManager.GetActiveScene().name;
            //string filename = EditorApplication.currentScene + "_" + exportedObjects;
            string filename = tSceneName + "_" + exportedObjects;

            int stripIndex = filename.LastIndexOf('/');//FIXME: Should be Path.PathSeparator

            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("Window/Road Architect/Export/Export each selected to single OBJ")]
    private 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 index = 0; index < selection.Length; index++)
        {
            Component[] meshfilter = selection[index].GetComponentsInChildren(typeof(MeshFilter));

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

            for (int m = 0; m < meshfilter.Length; m++)
            {
                exportedObjects++;
                mf[m] = (MeshFilter) meshfilter[m];
            }

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

        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!", "");
        }
    }


    [MenuItem("Window/Road Architect/Export/Exporters by Hrafnkell Freyr Hlooversson from Unity3D wiki")]
    private static void DoNothing1()
    {
        Application.OpenURL("http://wiki.unity3d.com/index.php?title=ObjExporter");
    }
}
#endif