public void SetSelectedElement(Helix.Element3D model)
        {
            if (model != null && model.IsDescendentOf(manipulator))
            {
                return;
            }
            else
            {
                model = model?.FindInstanceParent();
            }

            if (model is BoxManipulator3D || model == selector.Target)
            {
                return;
            }

            if (model != null)
            {
                manipulator.CenterOffset = model.GetTotalBounds(true).Center;
                manipulator.Visibility   = Visibility.Visible;
            }
            else
            {
                manipulator.Visibility = Visibility.Collapsed;
            }

            manipulator.Target = selector.Target = model;
            highlighter.Target = null;

            GetHost()?.OnElementSelected(model);
        }