Showing only the border of the top volume in opengl

I have a drawing of some shapes in opengl, but I would like to be able to see the full dimensions of their container, the top volume, a box. I see that you can use the TGeoManager::SetTopVisibile() option to draw the top volume, but that obscures what’s inside it. I’d like to just have the borders visible. Is this possible? Thanks!

press “T” when your mouse is in the viewer (See gl viewer canvas help button)

Rene