protected static void ModelPropertyChanged(DependencyObject d, DependencyPropertyChangedEventArgs e)
{
ReusableUIElement3D reusableElement = (ReusableUIElement3D)d;
reusableElement.Visual3DModel = reusableElement.Model;
}
protected static void VisualPropertyChanged(DependencyObject d, DependencyPropertyChangedEventArgs e)
{
ReusableUIElement3D reusableElement = (ReusableUIElement3D)d;
reusableElement.InvalidateModel();
}