protected void ApplyDrag()
        {
            List <GizmoTransform> parents = GizmoTransform.FilterParentsOnly(_targetTransforms);

            if (DragChannel == GizmoDragChannel.Offset)
            {
                foreach (var parentTransform in parents)
                {
                    parentTransform.Position3D = parentTransform.Position3D + _relativeDragOffset;
                }
            }
            else
            if (DragChannel == GizmoDragChannel.Rotation)
            {
                foreach (var parentTransform in parents)
                {
                    parentTransform.Rotation3D = _relativeDragRotation * parentTransform.Rotation3D;
                }
            }
        }