I have used setPlatformGeometry to add a simple scene graph
(rectangle) the right hand side of my canvas3D. I always want this
rectangle to be at the rhs of my window no matter what transformations
are going on which is why I used the PlatformGeometry in the
SimpleUniverse. However, when I resize my window, the rectangle
changes its size in relation to the width of the canvas. If I change
the height of the canvas, the rectangle size stays the same size.

The behavior I would expect from adding geometry to the ViewerPlatform
in the SimpleUniverse would be for the size of the rectangle to stay
proportionate to the size of the window. Does anyone know how I can
achieve this?

thanks,
Kristian.