Unity3DでMeshのPostureを固定する

FreezeMesh.cs

using UnityEngine;
using UnityEditor;
using System;
using System.Collections;
public class FreezeMesh : MonoBehaviour {
    [Flags]
    enum FreezeFlag {
        kSCALE = 1<<0,
        kROTATION,
        kTRANSLATION,
        kPROCESS_SHARED,
    }
    [MenuItem("Tools/FreezeMesh/Freeze Scale")]
    static void DoFreezeScale() {
        DoFreezing(FreezeFlag.kSCALE);
    }
    [MenuItem("Tools/FreezeMesh/Freeze Rotation")]
    static void DoFreezeRotation() {
        DoFreezing(FreezeFlag.kROTATION);
    }
    [MenuItem("Tools/FreezeMesh/Freeze Position")] // Unity用語に合わせた
    static void DoFreezeTranslation() {
        DoFreezing(FreezeFlag.kTRANSLATION);
    }
    [MenuItem("Tools/FreezeMesh/")]
    [MenuItem("Tools/FreezeMesh/Freeze Scale(Shared Mesh)")]
    static void DoFreezeScaleShared() {
        DoFreezing(FreezeFlag.kSCALE | FreezeFlag.kPROCESS_SHARED);
    }
    [MenuItem("Tools/FreezeMesh/Freeze Rotation(Shared Mesh)")]
    static void DoFreezeRotationShared() {
        DoFreezing(FreezeFlag.kROTATION | FreezeFlag.kPROCESS_SHARED);
    }
    [MenuItem("Tools/FreezeMesh/Freeze Position(Shared Mesh)")]
    static void DoFreezeTranslationShared() {
        DoFreezing(FreezeFlag.kTRANSLATION | FreezeFlag.kPROCESS_SHARED);
    }
    static void DoFreezing(FreezeFlag flag) {
        Undo.RegisterUndo(Selection.gameObjects, "Freeze Mesh");
        //Undo.RegisterSceneUndo("(Debug)Freeze Mesh");
        foreach (GameObject obj in Selection.gameObjects) {
            Freeze(obj, flag);
            EditorUtility.SetDirty(obj);
        }
    }
    // メッシュをコピーする
    // もしかしたら、これでは不完全かもしれない
    static Mesh DuplicateMesh(Mesh mesh) {
        Mesh newmesh = new Mesh();
        newmesh.vertices = (Vector3[])mesh.vertices.Clone();
        newmesh.normals = (Vector3[])mesh.normals.Clone();
        newmesh.tangents = (Vector4[])mesh.tangents.Clone();
        newmesh.uv = (Vector2[])mesh.uv.Clone();
        newmesh.uv2 = (Vector2[])mesh.uv2.Clone();
        newmesh.colors = (Color[])mesh.colors.Clone();
        newmesh.subMeshCount = mesh.subMeshCount;
        for (int i = 0; i < mesh.subMeshCount; ++i)
            newmesh.SetTriangles(mesh.GetTriangles(i), i);
        newmesh.boneWeights = (BoneWeight[])mesh.boneWeights.Clone();
        newmesh.bindposes = (Matrix4x4[])mesh.bindposes.Clone();
        return newmesh;
    }
    static void Freeze(GameObject obj, FreezeFlag flag) {
        bool processshared = ((flag & FreezeFlag.kPROCESS_SHARED) == FreezeFlag.kPROCESS_SHARED);
        MeshFilter meshfilter = obj.GetComponent<MeshFilter>();
        Mesh mesh = (processshared)? meshfilter.sharedMesh : DuplicateMesh(meshfilter.sharedMesh);
        Vector3 trs = Vector3.zero;
        Quaternion rot = Quaternion.identity;
        Vector3 sca = new Vector3(1.0f, 1.0f, 1.0f);
        if ((flag & FreezeFlag.kSCALE) == FreezeFlag.kSCALE) {
            sca = obj.transform.localScale;
            obj.transform.localScale = new Vector3(1.0f, 1.0f, 1.0f);
        }
        if ((flag & FreezeFlag.kROTATION) == FreezeFlag.kROTATION) {
            rot = obj.transform.localRotation;
            obj.transform.localRotation = Quaternion.identity;
        }
        if ((flag & FreezeFlag.kTRANSLATION) == FreezeFlag.kTRANSLATION) {
            trs = obj.transform.localPosition;
            obj.transform.localPosition = Vector3.zero;
        }
        Matrix4x4 mtx = Matrix4x4.TRS(trs, rot, sca);
        mesh.vertices = MultiplyPoint(mtx, mesh.vertices);
        mesh.normals = MultiplyVector(mtx, mesh.normals, true);
        mesh.RecalculateBounds();
        if (!processshared) {
            DestroyImmediate(meshfilter);
            obj.AddComponent<MeshFilter>().mesh = mesh;
        }
    }
    static Vector3[] MultiplyPoint(Matrix4x4 mtx, Vector3[] vec) {
        int len = vec.Length;
        Vector3[] newvec = new Vector3[len];
        for (int i = 0; i < len; ++i) {
            newvec[i] = mtx.MultiplyPoint(vec[i]);
        }
        return newvec;
    }
    static Vector3[] MultiplyVector(Matrix4x4 mtx, Vector3[] vec, bool ignorescale) {
        Matrix4x4 mtx2 = Matrix4x4.identity;
        if (ignorescale) {
            for (int i = 0; i < 3; ++i) {
                mtx2.SetColumn(i, mtx.GetColumn(i).normalized);
            }
        } else {
            mtx2 = mtx;
        }
        int len = vec.Length;
        Vector3[] newvec = new Vector3[len];
        for (int i = 0; i < len; ++i) {
            newvec[i] = mtx2.MultiplyVector(vec[i]);
        }
        return newvec;
    }
}