// Functions
        //--------------------------------------
        public void SetMeshGroup(apMeshGroup meshGroup)
        {
            if (meshGroup == null)
            {
                _childMeshGroup = null;

                //ID를 반납하자
                if (_childMeshGroupTransform != null)
                {
                    //_portrait.PushUniqueID_Transform(_childMeshGroupTransform._transformUniqueID);
                    _portrait.PushUnusedID(apIDManager.TARGET.Transform, _childMeshGroupTransform._transformUniqueID);

                    _childMeshGroupTransform = null;
                }
                _renderUnit = null;
            }
            if (meshGroup != null)
            {
                _childMeshGroup = meshGroup;

                bool resetMeshGroupTransform = false;
                if (_childMeshGroupTransform == null)
                {
                    resetMeshGroupTransform = true;
                }
                else if (_childMeshGroupTransform._meshGroupUniqueID != meshGroup._uniqueID)
                {
                    //_portrait.PushUniqueID_Transform(_childMeshGroupTransform._transformUniqueID);
                    _portrait.PushUnusedID(apIDManager.TARGET.Transform, _childMeshGroupTransform._transformUniqueID);

                    _childMeshGroupTransform = null;
                    resetMeshGroupTransform  = true;
                }

                if (resetMeshGroupTransform)
                {
                    //Root는 별도의 Transform_MeshGroup을 가진다.

                    //새로운 ID로 Transform을 만들자
                    //_childMeshGroupTransform = new apTransform_MeshGroup(_portrait.MakeUniqueID_Transform());
                    _childMeshGroupTransform = new apTransform_MeshGroup(_portrait.MakeUniqueID(apIDManager.TARGET.Transform));

                    _childMeshGroupTransform._meshGroupUniqueID = meshGroup._uniqueID;
                    _childMeshGroupTransform._nickName          = meshGroup._name;
                    _childMeshGroupTransform._meshGroup         = meshGroup;
                    _childMeshGroupTransform._matrix            = new apMatrix();
                    _childMeshGroupTransform._isVisible_Default = true;

                    _childMeshGroupTransform._depth = 1;

                    //추가
                    //Root Transform_MeshGroup에 해당하는 RenderUnit
                    _renderUnit = new apRenderUnit(_portrait, "Root");
                    _renderUnit.SetGroup(meshGroup, _childMeshGroupTransform, null);
                    _renderUnit._childRenderUnits.Add(meshGroup._rootRenderUnit);
                }
                else
                {
                    _childMeshGroupTransform._meshGroup = meshGroup;                    //Link만 하자
                    if (_renderUnit == null)
                    {
                        _renderUnit = new apRenderUnit(_portrait, "Root");
                        _renderUnit.SetGroup(meshGroup, _childMeshGroupTransform, null);
                        _renderUnit._childRenderUnits.Add(meshGroup._rootRenderUnit);
                    }
                    else
                    {
                        _renderUnit._meshGroupTransform = _childMeshGroupTransform;
                        _renderUnit._meshGroup          = meshGroup;
                        _renderUnit._childRenderUnits.Clear();
                        _renderUnit._childRenderUnits.Add(meshGroup._rootRenderUnit);
                    }
                }
            }
        }