There's no way to specify a door swing in OBJ format. The OBJ format isn't that clever! 
Does this mean it is better to submit models of windows/doors/light-sources in sh3f (furniture library) format? And if so, is there a preferred standard for the various properties that would make life easier?
ok
PS - just realising that for instance my categories is unlikely to be to everyone's taste... - see sourceforge submission of window
