unity 将文件导出成Obj格式存储在任意位置

接上一篇将对象存储为fbx这一篇文章就是将对象存储为obj格式。

优势是可以存储在任意位置，只要可以就可以。亲测可用移动端和pc端，应该是都可以的，因为可以存在沙盒中~~~~

劣势暂时还不知道，可能obj不支持其他一些3D引擎吧。。。

方法很简单，直接调用CreatMesh，传参即可。

path地址~例如 application.streamingasets+“acc/”
meshname 存储文件的文件名 例如 ： “acc.obj”
ms 对象mesh网格

这个方法可以搭配我的上上篇文章使用，欢迎大家浏览我的博客~~~

嗯 就这样吧 这个比较简单 就不说太多了，具体的转化数据的那个方法，大家感兴趣可以自己测试

方法我是在网上找的，大家可以找找原著，我就不厚脸皮了~~~~~

大家可以一块交流有什么问题的话添加 QQ群 207019099

 /// <summary>
    /// 存储文件到沙盒中
    /// </summary>
    public static void CreatMesh(string path, string meshname, Mesh ms)
    {
        //回掉
        if (!Directory.Exists(path))
        {
            Directory.CreateDirectory(path);
        }
        using (StreamWriter streamWriter = new StreamWriter(path + meshname))
        {
            streamWriter.Write(MeshToString(ms, new Vector3(-1f, 1f, 1f)));
            streamWriter.Close();
        }
    }
    /// <summary>
    /// mesh转化为数据
    /// </summary>
    /// <param name="mf"></param>
    /// <param name="scale"></param>
    /// <returns></returns>
    public static string MeshToString(Mesh mf, Vector3 scale)
    {
        Mesh mesh = mf;
        //Material[] sharedMaterials = mf.GetComponent<Renderer>().sharedMaterials;
        //Vector2 textureOffset = mf.GetComponent<Renderer>().material.GetTextureOffset("_MainTex");//这里对于我来说么用，去掉了
        //Vector2 textureScale = mf.GetComponent<Renderer>().material.GetTextureScale("_MainTex");//这里对于我来说么用，就改掉了1，1
        Vector2 textureOffset = new Vector2(0, 0);
        Vector2 textureScale = new Vector2(1, 1);

        StringBuilder stringBuilder = new StringBuilder().Append("mtllib design.mtl")
            .Append("\n")
            .Append("g ")
            .Append(mf.name)
            .Append("\n");

        Vector3[] vertices = mesh.vertices;
        for (int i = 0; i < vertices.Length; i++)
        {
            Vector3 vector = vertices[i];
            stringBuilder.Append(string.Format("v {0} {1} {2}\n", vector.x * scale.x, vector.y * scale.y, vector.z * scale.z));
        }

        stringBuilder.Append("\n");

        Dictionary<int, int> dictionary = new Dictionary<int, int>();

        if (mesh.subMeshCount > 1)
        {
            int[] triangles = mesh.GetTriangles(1);

            for (int j = 0; j < triangles.Length; j += 3)
            {
                if (!dictionary.ContainsKey(triangles[j]))
                {
                    dictionary.Add(triangles[j], 1);
                }

                if (!dictionary.ContainsKey(triangles[j + 1]))
                {
                    dictionary.Add(triangles[j + 1], 1);
                }

                if (!dictionary.ContainsKey(triangles[j + 2]))
                {
                    dictionary.Add(triangles[j + 2], 1);
                }
            }
        }

        for (int num = 0; num != mesh.uv.Length; num++)
        {
            Vector2 vector2 = Vector2.Scale(mesh.uv[num], textureScale) + textureOffset;

            if (dictionary.ContainsKey(num))
            {
                stringBuilder.Append(string.Format("vt {0} {1}\n", mesh.uv[num].x, mesh.uv[num].y));
            }
            else
            {
                stringBuilder.Append(string.Format("vt {0} {1}\n", vector2.x, vector2.y));
            }
        }

        for (int k = 0; k < mesh.subMeshCount; k++)
        {
            stringBuilder.Append("\n");

            if (k == 0)
            {
                stringBuilder.Append("usemtl ").Append("Material_design").Append("\n");
            }

            if (k == 1)
            {
                stringBuilder.Append("usemtl ").Append("Material_logo").Append("\n");
            }

            int[] triangles2 = mesh.GetTriangles(k);

            for (int l = 0; l < triangles2.Length; l += 3)
            {
                stringBuilder.Append(string.Format("f {0}/{0} {1}/{1} {2}/{2}\n", triangles2[l] + 1, triangles2[l + 2] + 1, triangles2[l + 1] + 1));
            }
        }

        return stringBuilder.ToString();
    }