/// <summary>
        /// 【SDK3】<see cref="BlendShapePreset.Blink"/>を変換し、視線追従を有効化します。
        /// </summary>
        /// <param name="avatar"></param>
        /// <param name="clips"></param>
        /// <param name="useShapeKeyNormalsAndTangents"/>
        private static void EnableEyeLook(
            GameObject avatar,
            IEnumerable <VRMBlendShapeClip> clips,
            bool useShapeKeyNormalsAndTangents
            )
        {
            VRMBlendShapeClip clip = clips.FirstOrDefault(c => c.Preset == BlendShapePreset.Blink);
            var lookAtBoneApplyer  = avatar.GetComponent <VRMLookAtBoneApplyer>();

            if (!clip && !lookAtBoneApplyer)
            {
                return;
            }

            var renderer = avatar.transform.Find(VRChatUtility.AutoBlinkMeshPath).GetComponent <SkinnedMeshRenderer>();
            var mesh     = renderer.sharedMesh;

            if (clip)
            {
                mesh.AddBlendShapeFrame(
                    BlendShapeReplacer.BlinkShapeKeyName,
                    1,
                    BlendShapeReplacer.GenerateShapeKey(
                        clip.ShapeKeyValues,
                        BlendShapeReplacer.GetAllShapeKeys(mesh, useShapeKeyNormalsAndTangents)
                        ),
                    null,
                    null
                    );
                EditorUtility.SetDirty(mesh);
            }

#if VRC_SDK_VRCSDK3
            var descriptor = avatar.GetComponent <VRCAvatarDescriptor>();
            descriptor.enableEyeLook = true;

            var settings = new VRCAvatarDescriptor.CustomEyeLookSettings();

            if (clip)
            {
                settings.eyelidType         = VRCAvatarDescriptor.EyelidType.Blendshapes;
                settings.eyelidsSkinnedMesh = renderer;
                settings.eyelidsBlendshapes = new[] { mesh.blendShapeCount - 1, -1, -1 };
            }

            if (lookAtBoneApplyer)
            {
                settings.eyeMovement = new VRCAvatarDescriptor.CustomEyeLookSettings.EyeMovements()
                {
                    excitement = 0.5f,
                    confidence = 0,
                };
                settings.leftEye       = lookAtBoneApplyer.LeftEye.Transform;
                settings.rightEye      = lookAtBoneApplyer.RightEye.Transform;
                settings.eyesLookingUp = new VRCAvatarDescriptor.CustomEyeLookSettings.EyeRotations()
                {
                    left  = Quaternion.Euler(x: -lookAtBoneApplyer.VerticalUp.CurveYRangeDegree, 0, 0),
                    right = Quaternion.Euler(x: -lookAtBoneApplyer.VerticalUp.CurveYRangeDegree, 0, 0),
                };
                settings.eyesLookingDown = new VRCAvatarDescriptor.CustomEyeLookSettings.EyeRotations()
                {
                    left  = Quaternion.Euler(x: lookAtBoneApplyer.VerticalUp.CurveYRangeDegree, 0, 0),
                    right = Quaternion.Euler(x: lookAtBoneApplyer.VerticalUp.CurveYRangeDegree, 0, 0),
                };
                settings.eyesLookingLeft = new VRCAvatarDescriptor.CustomEyeLookSettings.EyeRotations()
                {
                    left  = Quaternion.Euler(0, y: -lookAtBoneApplyer.HorizontalOuter.CurveYRangeDegree, 0),
                    right = Quaternion.Euler(0, y: -lookAtBoneApplyer.HorizontalInner.CurveYRangeDegree, 0),
                };
                settings.eyesLookingRight = new VRCAvatarDescriptor.CustomEyeLookSettings.EyeRotations()
                {
                    left  = Quaternion.Euler(0, y: lookAtBoneApplyer.HorizontalInner.CurveYRangeDegree, 0),
                    right = Quaternion.Euler(0, y: lookAtBoneApplyer.HorizontalOuter.CurveYRangeDegree, 0),
                };
            }

            descriptor.customEyeLookSettings = settings;
#endif
        }
        /// <summary>
        /// <see cref="BlendShapePreset.Neutral"/>、および<see cref="BlendShapePreset.Blink"/>を変換します。
        /// </summary>
        /// <remarks>
        /// 参照:
        /// 最新版(10/02時点)自動まばたきの実装【VRChat技術情報】 — VRChatパブリックログ
        /// <https://jellyfish-qrage.hatenablog.com/entry/2018/10/02/152316>
        /// VRchatでMMDモデルをアバターとして使う方法——上級者編 — 東屋書店
        /// <http://www.hushimero.xyz/entry/vrchat-EyeTracking#%E5%A4%A7%E5%8F%A3%E9%96%8B%E3%81%91%E3%82%8B%E5%95%8F%E9%A1%8C%E3%81%AE%E8%A7%A3%E6%B1%BA>
        /// 技術勢の元怒さんのツイート: “自動まばたきはまばたきシェイプキーを、まばたき防止のほうは自動まばたきのエナブルONOFFを操作してますね。 欲しければサンプル渡せますよ。… ”
        /// <https://twitter.com/gend_VRchat/status/1100155987216879621>
        /// momoma/ナル@VRChatter/VTuberさんのツイート: “3F目にBehavior 1のキーを追加したら重複しなくなったわ、なるほどな… ”
        /// <https://twitter.com/momoma_creative/status/1137917887262339073>
        /// </remarks>
        /// <param name="avatar"></param>
        /// <param name="clips"></param>
        /// <paramref name="useShapeKeyNormalsAndTangents"/>
        private static void SetNeutralAndBlink(
            GameObject avatar,
            IEnumerable <VRMBlendShapeClip> clips,
            bool useShapeKeyNormalsAndTangents
            )
        {
            AnimatorController neutralAndBlinkController
                = BlendShapeReplacer.CreateSingleAnimatorController(avatar: avatar, name: "blink");
            AnimationClip animationClip = neutralAndBlinkController.animationClips[0];

            VRMBlendShapeClip blinkClip = null;

            foreach (var preset in new[] { BlendShapePreset.Blink, BlendShapePreset.Neutral })
            {
                VRMBlendShapeClip clip = clips.FirstOrDefault(c => c.Preset == preset);
                if (!clip)
                {
                    continue;
                }

                if (preset == BlendShapePreset.Blink)
                {
                    blinkClip = clip;
                }

                foreach (var(shapeKeyName, shapeKeyWeight) in clip.ShapeKeyValues)
                {
                    var keys = BlendShapeReplacer.BlinkWeights;
                    if (preset == BlendShapePreset.Neutral)
                    {
                        if (blinkClip && blinkClip.ShapeKeyValues.ContainsKey(shapeKeyName))
                        {
                            // NEUTRALとBlinkが同一のシェイプキーを参照していた場合
                            float blinkShapeKeyWeight = blinkClip.ShapeKeyValues[shapeKeyName];
                            var   animationCurve      = new AnimationCurve();
                            foreach (var(seconds, blendShapePreset) in BlendShapeReplacer.NeutralAndBlinkWeights)
                            {
                                float weight;
                                switch (blendShapePreset)
                                {
                                case BlendShapePreset.Neutral:
                                    weight = shapeKeyWeight;
                                    break;

                                case BlendShapePreset.Blink:
                                    weight = blinkShapeKeyWeight;
                                    break;

                                default:
                                    weight = 0;
                                    break;
                                }
                                animationCurve.AddKey(new Keyframe(seconds, weight));
                            }

                            animationClip.SetCurve(
                                "",
                                typeof(SkinnedMeshRenderer),
                                "blendShape." + shapeKeyName,
                                animationCurve
                                );
                            continue;
                        }

                        keys = BlendShapeReplacer.NeutralWeights;
                    }

                    SetBlendShapeCurve(animationClip, shapeKeyName, shapeKeyWeight, keys, setRelativePath: false);
                }

                foreach (MaterialValueBinding binding in clip.MaterialValues)
                {
                    // TODO
                }
            }

            Transform transform = avatar.transform.Find(VRChatUtility.AutoBlinkMeshPath);

            transform.gameObject.AddComponent <Animator>().runtimeAnimatorController = neutralAndBlinkController;

            // VRChat側の自動まばたきを回避
            Mesh mesh = transform.GetSharedMesh();
            IEnumerable <BlendShape> shapeKeys = BlendShapeReplacer.GetAllShapeKeys(mesh, useShapeKeyNormalsAndTangents);

            mesh.ClearBlendShapes();
            foreach (string name in BlendShapeReplacer.OrderedBlinkGeneratedByCatsBlenderPlugin)
            {
                BlendShapeReplacer.AddDummyShapeKey(mesh: mesh, name: name);
            }
            foreach (BlendShape shapeKey in shapeKeys)
            {
                if (BlendShapeReplacer.OrderedBlinkGeneratedByCatsBlenderPlugin.Contains(shapeKey.Name))
                {
                    continue;
                }

                mesh.AddBlendShapeFrame(
                    shapeKey.Name,
                    BlendShapeReplacer.MaxBlendShapeFrameWeight,
                    shapeKey.Positions.ToArray(),
                    shapeKey.Normals.ToArray(),
                    shapeKey.Tangents.ToArray()
                    );
            }
            EditorUtility.SetDirty(mesh);
        }
        /// <summary>
        /// Animatorコンポーネントを使用せずに、<see cref="BlendShapePreset.Neutral"/>、および<see cref="BlendShapePreset.Blink"/>を変換します。
        /// </summary>
        /// <remarks>
        /// <see cref="BlendShapePreset.Blink"/>が関連付けられたメッシュが見つからない、またはそのメッシュに
        /// <see cref="BlendShapeReplacer.OrderedBlinkGeneratedByCatsBlenderPlugin"/>がそろっていれば何もしません。
        /// それらのキーが存在せず、<see cref="BlendShapePreset.Blink_L"/>、<see cref="BlendShapePreset.Blink_R"/>がいずれも設定されていればそれを優先します。
        /// </remarks>
        /// <param name="avatar"></param>
        /// <param name="clips"></param>
        /// <param name="useShapeKeyNormalsAndTangents"></param>
        private static void SetBlinkWithoutAnimator(
            GameObject avatar,
            IEnumerable <VRMBlendShapeClip> clips,
            bool useShapeKeyNormalsAndTangents
            )
        {
            var  renderer = avatar.transform.Find(VRChatUtility.AutoBlinkMeshPath).GetComponent <SkinnedMeshRenderer>();
            Mesh mesh     = renderer.sharedMesh;

            if (BlendShapeReplacer.GetBlendShapeNames(mesh: mesh)
                .Take(BlendShapeReplacer.OrderedBlinkGeneratedByCatsBlenderPlugin.Count())
                .SequenceEqual(BlendShapeReplacer.OrderedBlinkGeneratedByCatsBlenderPlugin))
            {
                return;
            }

            IEnumerable <BlendShape> shapeKeys = BlendShapeReplacer.GetAllShapeKeys(mesh, useShapeKeyNormalsAndTangents);

            mesh.ClearBlendShapes();

            var dummyShapeKeyNames = new List <string>();

            if (clips.FirstOrDefault(c => c.Preset == BlendShapePreset.Blink_L) &&
                clips.FirstOrDefault(c => c.Preset == BlendShapePreset.Blink_R))
            {
                mesh.AddBlendShapeFrame(
                    BlendShapeReplacer.OrderedBlinkGeneratedByCatsBlenderPlugin.ElementAt(0),
                    BlendShapeReplacer.MaxBlendShapeFrameWeight,
                    BlendShapeReplacer.GenerateShapeKey(
                        namesAndWeights: clips.First(c => c.Preset == BlendShapePreset.Blink_L).ShapeKeyValues,
                        shapeKeys: shapeKeys
                        ),
                    null,
                    null
                    );
                mesh.AddBlendShapeFrame(
                    BlendShapeReplacer.OrderedBlinkGeneratedByCatsBlenderPlugin.ElementAt(1),
                    BlendShapeReplacer.MaxBlendShapeFrameWeight,
                    BlendShapeReplacer.GenerateShapeKey(
                        namesAndWeights: clips.First(c => c.Preset == BlendShapePreset.Blink_R).ShapeKeyValues,
                        shapeKeys: shapeKeys
                        ),
                    null,
                    null
                    );
            }
            else
            {
                mesh.AddBlendShapeFrame(
                    BlendShapeReplacer.OrderedBlinkGeneratedByCatsBlenderPlugin.ElementAt(0),
                    BlendShapeReplacer.MaxBlendShapeFrameWeight,
                    BlendShapeReplacer.GenerateShapeKey(
                        namesAndWeights: clips.First(c => c.Preset == BlendShapePreset.Blink).ShapeKeyValues,
                        shapeKeys: shapeKeys
                        ),
                    null,
                    null
                    );
                dummyShapeKeyNames.Add(BlendShapeReplacer.OrderedBlinkGeneratedByCatsBlenderPlugin.ElementAt(1));
            }
            dummyShapeKeyNames.AddRange(BlendShapeReplacer.OrderedBlinkGeneratedByCatsBlenderPlugin.Skip(2));
            foreach (string name in dummyShapeKeyNames)
            {
                BlendShapeReplacer.AddDummyShapeKey(mesh: mesh, name: name);
            }

            foreach (BlendShape shapeKey in shapeKeys)
            {
                if (BlendShapeReplacer.OrderedBlinkGeneratedByCatsBlenderPlugin.Contains(shapeKey.Name))
                {
                    continue;
                }

                mesh.AddBlendShapeFrame(
                    shapeKey.Name,
                    BlendShapeReplacer.MaxBlendShapeFrameWeight,
                    shapeKey.Positions.ToArray(),
                    shapeKey.Normals.ToArray(),
                    shapeKey.Tangents.ToArray()
                    );
            }

            EditorUtility.SetDirty(mesh);
        }
        /// <summary>
        /// リップシンクの設定を行います。
        /// </summary>
        /// <remarks>
        /// <see cref="BlendShapePreset.A"/>、<see cref="BlendShapePreset.I"/>、<see cref="BlendShapePreset.O"/>が
        /// 単一のフレームを持つシェイプキーが存在しない場合、設定を行いません。
        /// 生成するシェイプキー名と同じシェイプキーが存在する場合、それを利用します。
        /// </remarks>
        /// <param name="avatar"></param>
        /// <param name="clips"></param>
        /// <param name="useShapeKeyNormalsAndTangents"></param>
        private static void SetLipSync(
            GameObject avatar,
            IEnumerable <VRMBlendShapeClip> clips,
            bool useShapeKeyNormalsAndTangents
            )
        {
            Transform transform = avatar.transform.Find(VRChatUtility.AutoBlinkMeshPath);
            var       renderer  = transform.GetComponent <SkinnedMeshRenderer>();
            Mesh      mesh      = renderer.sharedMesh;

            foreach (var preset in new[] { BlendShapePreset.A, BlendShapePreset.I, BlendShapePreset.O })
            {
                if (!clips.FirstOrDefault(c => c.Preset == preset))
                {
                    return;
                }
            }

            IEnumerable <BlendShape> shapeKeys = BlendShapeReplacer.GetAllShapeKeys(mesh, useShapeKeyNormalsAndTangents);

            foreach (var(newName, values) in BlendShapeReplacer.VisemeShapeKeyNamesAndValues)
            {
                if (mesh.GetBlendShapeIndex(newName) != -1)
                {
                    continue;
                }

                Vector3[] deltaVertices = null;
                foreach (Vector3[] vertices in values.SelectMany(presetAndWeight =>
                                                                 clips.First(clip => clip.Preset == presetAndWeight.Key).ShapeKeyValues.Select(
                                                                     shapeKeyNameAndWeight => shapeKeys
                                                                     .First(shapeKey => shapeKey.Name == shapeKeyNameAndWeight.Key)
                                                                     .Positions
                                                                     .Select(vertix => vertix * (shapeKeyNameAndWeight.Value / VRMUtility.MaxBlendShapeBindingWeight * presetAndWeight.Value))
                                                                     .ToArray()
                                                                     )
                                                                 ))
                {
                    if (deltaVertices == null)
                    {
                        deltaVertices = vertices;
                        continue;
                    }

                    for (var i = 0; i < deltaVertices.Length; i++)
                    {
                        deltaVertices[i] += vertices[i];
                    }
                }

                mesh.AddBlendShapeFrame(
                    newName,
                    BlendShapeReplacer.MaxBlendShapeFrameWeight,
                    deltaVertices,
                    null,
                    null
                    );
            }
            EditorUtility.SetDirty(mesh);

#if VRC_SDK_VRCSDK2 || VRC_SDK_VRCSDK3
            var avatarDescriptor = avatar.GetComponent <VRC_AvatarDescriptor>();
            avatarDescriptor.lipSync           = VRC_AvatarDescriptor.LipSyncStyle.VisemeBlendShape;
            avatarDescriptor.VisemeSkinnedMesh = renderer;
            avatarDescriptor.VisemeBlendShapes
                = BlendShapeReplacer.VisemeShapeKeyNamesAndValues.Select(nameAndValues => nameAndValues.Key).ToArray();
#endif
        }