private void chkWest_Checked(object sender, RoutedEventArgs e)
{
westDoor = MeshFactory.MakeVerticalDoorWall(this);
canvasRoom.Children.Add(westDoor);
westDoor.SetValue(Canvas.LeftProperty, -20.0 * widthRatio);
westDoor.SetValue(Canvas.TopProperty, 800.0 * heightRatio);
}
